What is the material that the headlight gear pins are made of like? Mine have deteriorated and need replacement, but the pins Rodney and TFS sell look little different than slices of a rod of polyurethane-like plastic. Rodney's are made of delrin. Delrin is supposed to be a hard plastic, and it's properties sound similar to hard polyurethane. How much shock are they supposed to absorb? As easy as they are to replace, I wouldn't mind using any sort of semi-hard wood or plastic dowl as I know that will technically work, but I presume the pins are intended to absorb shock and thus protect the gears from stripping. Does anyone know just how hard they are? Can you depress them with a fingernail?
$12 dollars (that's including shipping) isn't a ton of money, but those parts do not look to be worth that much.
The pins are not there to absorb shock, they act as a clutch between the gear and the shaft. They are very rigid and even though other materials might work, do you really want to have to rebuild the headlights a second time when you discover that the material you used does not provide the right traction between the gear and the output shaft?
Originally posted by lateFormula: The pins are not there to absorb shock, they act as a clutch between the gear and the shaft. They are very rigid and even though other materials might work, do you really want to have to rebuild the headlights a second time when you discover that the material you used does not provide the right traction between the gear and the output shaft?
Sorry but the pins do absorb shock etc. The pins are also a mechanical "fuse," called a Shear Pin, that breaks before other parts will fail. And You want the pins to fail when the module is dieing. You could find fried, even melted, motors from the dead module.
Shear pins/bolts/keys are a balancing act... Too soft and pins will fail, likely often. Too hard and more expensive parts will fail, like the gear or the output shaft with the aluminum hub. Especially when Module have problems.
Two common examples: Some of you have "broken the key" on the flywheel on small gas engines, like when the lawnmower blade hits one too many rocks. Many new snowblowers have plastic shear pins that breaks when the auger hits anything.
GM design the pins a bit soft that will fail in normal use over time... Many using Delrin and other harder materials can cause problems too, like some here have striped Aluminum hub on the output shaft. (Use PFF search)
I got Delrin pins before I found out the pins are "shear" parts... maybe Delrin is too hard.
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
Thanks Ogre. Do you have any ideas? I imagine standard rubber rod would be too soft. Maybe a polyurethane material like is used in prothane suspension would work.
Too soft is a pain but too hard is a bigger headache, even a nightmare.
To expand Example above: Replacing a shear key w/ a steel key (And many people do just that) in a lawnmower's flywheel then can cause the crankshaft to fail the next time you hit a big rock.
Some Rubber, Polyurethane, and others plastic/nylon could work. Problem is they have thousands/millions of formals.
To find a good one would help if we had old "pins" specs. No-one I know have that info. To find a better one... You likely need a intact pins, and even a good motor and module etc, and shop to analyze the part and the load the part will see. That cost $...
With all due respect Ogre, those pins act as a clutch. There is no mechanism by which those pins can "shear", unless they completely break down and turn to dust which is what they naturally do over time. Next time you need to rebuild one of these headlight motors, buy a set of Rodney's pins, and before you install them, grind 1mm off of their length. Reassemble the motor and you will find that the motor cannot lift the headlight assembly because the large gear cannot transmit it's rotational energy to the steel plate that is fastened to the output shaft. Those pins act as a clutch and will provide slippage if the motor is overloaded. The headlight drive assembly of large gear, delrin/nylon pins, and output shaft are controlled to have a specific spacing (preload) between the components by the shim washers that are used in the housing.
[This message has been edited by lateFormula (edited 06-01-2013).]
It looks like I'm in the perfect position, then. I have one good motor and one with broken pins. I also work at a shop with a quality metal-turning lathe. I'll do my own measurements of the good motor's pins and see if I want to try turning my own material. Thanks.
Some possibilities pre-analysis: -polyurethane -hdpe (high-density polyethylene)
You guys really crack me up. You must have too much time on your hands... $20 and you can have all the bushings and gaskets to do both lights and not have to worry about them for years to come.. ...Or spend 5 hours (or more) screwing around trying to make something work...
If for some reason you just don't want to buy them from the previously mentioned Fiero vendors, Ecklers sells them too. But they're $2 each too. [long whistle]
I'd rather spend the $20 and be done with the job in under an hour.
Agreed! The agony some people go through "reinventing the wheel" to save a couple of dollars amazes me too. ... and in the long run, it sometimes costs more in dollars or grief. We see it over on over on PFF in almost every category.
You have a point, and I would agree with you to an extent. My issue is more with the replacement material. If I understand what delrin is like, it seems to be a harder, tougher material than the original. From the design of the gear, t looks like the original material was made to compensate for something blocking the motion of the motor so that it would not strip the gears. If delrin is in fact too hard for this function, then using that material could be bad for the motors should something get in the way of them opening up, maybe even something as innocuous as ice freezing the headlight doors shut. Contrary to my original claim, I now agree that the price Rodney and TFS are charging is not, in fact, horribly high. They're providing a good service. I'm asking this question concerning proper material before I put the parts in lest the Ogre's theory is correct and it strips the gears.
All the best, -Michael
[This message has been edited by Fierology (edited 07-07-2013).]
With all due respect Ogre, those pins act as a clutch. There is no mechanism by which those pins can "shear", unless they completely break down and turn to dust which is what they naturally do over time. Next time you need to rebuild one of these headlight motors, buy a set of Rodney's pins, and before you install them, grind 1mm off of their length. Reassemble the motor and you will find that the motor cannot lift the headlight assembly because the large gear cannot transmit it's rotational energy to the steel plate that is fastened to the output shaft. Those pins act as a clutch and will provide slippage if the motor is overloaded. The headlight drive assembly of large gear, delrin/nylon pins, and output shaft are controlled to have a specific spacing (preload) between the components by the shim washers that are used in the housing.
Does the Delrin impede the slippage? It seems you are saying that it allows the motors to function as originally intended. Is this true? Thanks.
Originally posted by Fierology: If I understand what delrin is like, it seems to be a harder, tougher material than the original. ... I'm asking this question concerning proper material before I put the parts in lest the Ogre's theory is correct and it strips the gears.
Rodney etc is trying to make dowels/pins that last... I don't blame anyone. And I have Delrin dowels
I've taken apart 1 motor last week because has stuck down... (7/1/13. Too hot/wet to mess w/ other side) The replacement Delrin dowels look new after years of use but the gear was waiting to break because the dowels won't absorb enough shock. Lucky I found this before gear broke because Gen2 uses all ~3/4 of the teeth. I was able to rotate the gear so stall points at another set of teeth. (Edit: Changing stall point then you run thru the damage area.) {Stalled point is the motor stalled at end of travel.}
CLICK FOR FULL SIZE
Now I've got to search at junk yards looking for good gears... New Dowels source? Don't know. Right now I'm still using my Delrin parts. It took years to slow, I have some time... Just use new gears... Aftermarket/"Restoration" gears have a bad rep but is cheap if i can't find OE ones. Just use Metal gears... Might solve gear failure but not save output shaft if the dowels are too hard. Hard dowels + metal gear then next weak part fails, likely output shaft. and Metal gears Cost... $40-60 + shipping for 1 gear. http://www.ecklerscorvette....r-kit-1988-1996.html http://rodneydickman.com/ca...h=32&products_id=257
For the rest... Just buy what the Internet says is good... No Thanks. Reexamined the "Internet Wheel" is often a good thing.
Several vendors sell, even use, Delrin and other hard plastics. (I think Eckler's change/altered their dowels/pins... For 1, now their hollow.)
In designing Gen2 system, GM gave the pins a graceful way to fail and easy to fix. Anyone whine about OE dowel spec should try fixing Gen1 that loves to nickle and dime you to death. Bumpers bad, Gears bad, 1 to all relays are dead, limit switch is toast, etc, etc, etc... Worse, Gen1 is very good at killing you battery.
Repairing the dowels every few years is a pain (I can do it and I only have one hand that works.) but better that then fixing gears or messing to pin the output shaft pieces back together. (Output shaft problems use PFF etc search...)
You blame Delrin? Any pin harder then OE part can cause this damage.
Is it possible that other things can contribute to this? Old age of Gen2 parts likely won't help but adding new Delrin pins then old part will fail faster then "normal."
(Edit for a short version) (9/15 Edit to fix image)
[This message has been edited by theogre (edited 09-23-2015).]
A shear pin should shear if sometnhing else goes wrong with the system. If it shears when nothing else is wrong then the shear pin is too weak. The pin should let go just before something else more expensive fails, if your pin has sheared and nothing else is wrong then the pin was not strong enough. Larry
update... I made this "cut away" view today to show how the dowels get a beating each time the motor is on. (I took pictures to make this at same as gear above but lost track of them.)
CLICK FOR FULL SIZE
Notice the dowels make a very small amount of contact on the output shaft. That point gets all the load from the gear side of them. Over time, the OE dowels will deform way before they fail and turn to dust.
Grinding to dust is more accurate. The flat sides of gear opening and shape of output part acts as a mortar and pestle (wikiHow) and just grind the dowels to dust and stops working at all. You might find bigger pieces but most are "stuck" in more open areas and doesn't make the unit to operate or may make it work sometimes.
W/o the dowels, the gear just spins around the metal part.
You might take note that some do sell these pins for less. The reason probably is they are probably cast injection molded plastic (hopefully Delrin). Years ago you could buy these at auto stores and they were turned Delrin. Now they are cast Delrin which has a lot shorter service life than the (turned from Delrin rod) Delrin torque pins. Mine are turned Delrin.
This idea was introduced (I believe) by Ford many, many years ago for electric window motors. The pins are there for a reason.
------------------ Rodney Dickman
Fiero Parts And Acc's Web Page: All new web page!:www.rodneydickman.com Rodney Dickman's Fiero accessories 7604 Treeview Drive Caledonia, WI 53108 Phone/Fax (262) 835-9575
[This message has been edited by Rodney (edited 09-23-2015).]
i work mostly with generation 1 motors. They work similarly but still dis similarly. They also use bump stops and in both motors, the bump stop do absorb shock. In the case of Gen 2, the module turns off the motor when it locks up. Generation 1 uses breaker points.
I've experimented with various materials for bump stops. Maple and plastic dowels, threaded rod, and other materials. I've seen motors filled with RTV and J & B Weld and even threaded nuts, too. In the case of the maple dowels, they began to splinter. The plastic dowels, and threaded rod were too hard and I started to see the same result Ogre illustrates. Some of the aftermarket dowels were too soft and caused the Gen. 1 motors to continue to cycle.
I eventually stumbled upon a very low mileage set of motors that had a perfect set of original bump stops. I've since acquired two more sets, one set of which has bumpstops of the green material, but they've not been tested. I also have a set of 20,000 mile Generation 2 motors that were stored inside when the car was totaled. Someday I'll have them tested. Generation 1 original bumpstops
I had my former partner's machine shop do a Rockwell Hardness test. I then searched various materials until I found one that closely matched. Finding that product was the difficult part, but I finally succeeded. Some of my motors have been out there for at least 7 years. Either they're still working as they should, or they broke and the customer doesn't want to deal with me again, but I like to think they're still working.
Edit to add: The Generation 2 shaft shown in the center of Ogre's picture will simply continue to turn when the bumpstops crumble. At that point, no further damage can be done to the inside workings of the motor. The Generation 1 motor is a prime example of what can happen if bumpstops are used that are too hard. The metal drive plate in this Generation 1 gear holds the bumpstops captive underneath it. There are 4 fingers, one on either corner that keep the bump stops from coming out. They exert force against the bumpstops when the motor suddenly stops. When the bumpstops crumble, those steel fingers then start to slam against the hard plastic ribs of the gears. Either the gear teeth strip or the metal fingers break off. Luckily, it's usually the softer plastic gear teeth, but I've seen a broken metal plate.
[This message has been edited by fierofool (edited 09-23-2015).]
I have one set of these black rubber bump stops. I believe I got them from a headlight motor that has the plastic intermediate gear. I think these are certainly very rare. Most had the green bump stops and the metal intermediate gear. I still have a few of these NOS green bump stops. When I bought all the left over 84-86 headlight motor obsolete parts from the original manufacturer that made the 84-86 headlight motors they sent me only green bump stops.
Years ago I had many more OEM plastic gears than I had green bump stops. So I thought for a long time on what I could use to replace the green bump stops. One day I thought of using rubber O ring material. That seems to work fine. The FS should thank me as they copied my O ring idea and now also sell these bump stops made out of rubber O ring material.
------------------ Rodney Dickman
Fiero Parts And Acc's Web Page: All new web page!:www.rodneydickman.com Rodney Dickman's Fiero accessories 7604 Treeview Drive Caledonia, WI 53108 Phone/Fax (262) 835-9575
The durometer of TFS bump stops seems to be a little softer than yours. I've never had problems with yours compressing the way theirs does. I had given some thought to having a mold made and then casting these in polyurethane but my former partner was killed in a plane crash and the machine shop closed up. Never got around to it after that.
[This message has been edited by fierofool (edited 09-24-2015).]
Originally posted by Rodney: You might take note that some do sell these pins for less. The reason probably is they are probably cast injection molded plastic (hopefully Delrin). Years ago you could buy these at auto stores and they were turned Delrin. Now they are cast Delrin which has a lot shorter service life than the (turned from Delrin rod) Delrin torque pins. Mine are turned Delrin.
This idea was introduced (I believe) by Ford many, many years ago for electric window motors. The pins are there for a reason.
I have your Delrin dowels/bushings/pins in the damaged gears shown above and didn't want a flame war because doesn't matter in the end who made them. Some have use your set, Ecker's, and others then after they blow the output shaft joint or destroy the gear. Some have post here and elsewhere w/ problem use Delrin in the past, others just finally replace w/ Pro Rebuild or New units or, like many Gen1 users, they gave up fixing and sold the car or use other things like often illegal flush mount HL.
"You might take note that some do sell these pins for less. ... " Pin Cost is irreverent here. Dorman is ~$8 each set of 3. A bit softer plastic/Delrin might matter... Could be harder then OE but maybe not hard enough to cause problems. Again... It is a pain to replacing pins but safer to the motor and cheap to you then fixing dead gears or output shaft. Having a Known fail point is better then fixing gears, etc.
Ford/etc Window motors can look the same to most people but be made different in many ways and have no problems using Delrin. So Might be Good for whatever PW but not be for Gen2 HL motors.
Worse when HL Module has even minor problems... GM design have tolerance for amps drawn from the motor then add years of use. If the Module is a bit late kill power at the of travel and you use hard pins in the gear then likely = quick death to the gear teeth or output shaft. Even the HL lift itself as part of linkage is under high load to stop the motor. If you fix the motor bottom end very strong to last then you can fry the module and/or the motor from high current. (Depending how bad the electrical problem... the OE pins may not fail fast enough to matter.) If module can't "see" the amp spike when motor stalls the you hope the timer run out before you have big problem or a fire. Quick Example: Cliff repairing fried MOSFET thread. Blew a FET, replace w/o much checking why and blew again and burn the board too. (Fusible Links C & D are not to protect the HL motor system but like most others are to stop the Battery from dumping 200+ amps in a short circuit.)
I have not tried Dorman PN 74410... They are part of or related to 747412 kit etc. (Many parts sources have them at local stores.) Some say there too soft (google other places) for HL motors but could have other problem making them fail. Like could be area get hot from weather/sun and radiator. This guy (YT vid, He's using big BB... ouch.) said Some Dorman pins are defective... In short, You want Clear pins not "milky" plastic.
I have one set of these black rubber bump stops. I believe I got them from a headlight motor that has the plastic intermediate gear. I think these are certainly very rare. Most had the green bump stops and the metal intermediate gear. I still have a few of these NOS green bump stops. When I bought all the left over 84-86 headlight motor obsolete parts from the original manufacturer that made the 84-86 headlight motors they sent me only green bump stops.
Years ago I had many more OEM plastic gears than I had green bump stops. So I thought for a long time on what I could use to replace the green bump stops. One day I thought of using rubber O ring material. That seems to work fine. The FS should thank me as they copied my O ring idea and now also sell these bump stops made out of rubber O ring material.
Rodney the black gen. 1 bump stops are from Firebird motors not Fiero. The durometer of the black ones are much softer than the green ones used in the Fiero's and the black ones do not crumble like the green ones. Every Firebird motor I have opened up has the plastic cog gear set, black bumpers, and a softer spring since the Firebird motors do not work against headlight doors with a torsion spring like Fiero motors. For this reason Firebird motors should not be used in Fiero's because the gears will not last and the limit switch may activate before the headlights are fully opened.
The black bump stops in my picture came from a Fiero. Motor removed and opened by me, personally. They may be the same as used in the Firebird, but they came out of a Fiero and a Fiero motor.
Are you sure the motor was original to the Fiero? Correct part number? I have rebuilt at least 500 of these motors over the years and Fiero motors always have green bumpers (or usually green bits) and the Firebird motors always have the black ones (still intact). Perhaps the motor originally came from a Firebird and the PO installed it on your Fiero. The motors look identical on the outside. Only difference is the part number on the tag and 85-86 Firebird motors have a single 3-wire plug.
I'm just trying to get accurate information out there and this has been my experience.
They came from a pullapart car. What year, I don't remember since I've been into so many and retrieved so many motors from them. I do lean toward it being one of the earlier years, though.
When I get a motor, I usually look to see if the brush set is good and check to see if there's any play in the arm attached to the through shaft. Tells me if the bump stops are any good. If the bump stops are good, the motor has probably had little use.
As was my practice, I opened them up to replace the gears with TFS plastic gears and my own version of bump stops and found the black rubber ones. Both motors had the black ones. The second set of black ones also came from one vehicle as did the green ones. It's possible but I think it unlikely that two different vehicles got a full set of motors from Firebirds. I never check the silver tags on the motors, so I don't really know.
The green bump stops are actually much harder than the black ones. They really feel like they're made of plastic. The black ones feel more like neoprene rubber.
The green bump stops are actually much harder than the black ones. They really feel like they're made of plastic. The black ones feel more like neoprene rubber.
The NOS green bumpers I have on hand are fairly soft. Especially the ends because they have the hole in the ends.
------------------ Rodney Dickman
Fiero Parts And Acc's Web Page: All new web page!:www.rodneydickman.com Rodney Dickman's Fiero accessories 7604 Treeview Drive Caledonia, WI 53108 Phone/Fax (262) 835-9575
The NOS green bumpers I have on hand are fairly soft. Especially the ends because they have the hole in the ends.
That probably means the ones I have are very old. I thought about using them to make a mold. Have you? They definitely will never go back into a motor. BTW, Rodney, I stopped using the plastic gears and recommend your metal ones to my customers. I'll rebuild with any gear my customer wants or provides, but I like the way your gear retains the bump stop. Being contained in a similar size cavity, I think it helps to prevent the bump stop from deforming, compared to being able to flatten in the normal open cavity of the plastic gear.
I don't want to get into the argument but I have used the Delrin pins to rebuild the Gen II headlight motors myself. They work fine but I feel that this fix will not last with regular use as they provide almost no cushioning action . Now with the introduction of the new Cardone motors we have a back up in case that happens. I installed one recently and it seems to work fine but the headlight doors just go up slightly slower. Its a heavy duty motor assembly BUT it is Made in China so who knows????
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
Originally posted by Dennis LaGrua: I don't want to get into the argument but I have used the Delrin pins to rebuild the Gen II headlight motors myself. They work fine but I feel that this fix will not last with regular use as they provide almost no cushioning action . Now with the introduction of the new Cardone motors we have a back up in case that happens. I installed one recently and it seems to work fine but the headlight doors just go up slightly slower. Its a heavy duty motor assembly BUT it is Made in China so who knows????
China made likely new but to make sure... New or Rebuild? Cardone Both and come w/ same warranty but... AZ will honor most warranties w/ just phone # to id the buyer. (I returned 10+ year old dead starter last year and AZ still honored the warranty.) Others will bi--- unless you show the receipt and some return to Same store location too.
[This message has been edited by theogre (edited 09-25-2015).]
China made likely new but to make sure... New or Rebuild? Cardone Both and come w/ same warranty but... AZ will honor most warranties w/ just phone # to id the buyer. (I returned 10+ year old dead starter last year and AZ still honored the warranty.) Others will bi--- unless you show the receipt and some return to Same store location too.
Cardone used to rebuild the motors, but now sells brand new GEN 2 motors. They are Made in China look like the GM units, the motors feel heavy duty and function well. Cost is $85 each. Only time will tell if these new Cardone units will hold up but you use headlights to drive at night, so the use in not 100% of your driving time. When I encounter a motor that can not easily be repaired (broken off screws) I'll just buy the Cardone I wish that Cardone would come out with a new GEN 1 headlight motor. My neighbor drives an 84 and his headlight motors did not go up. We checked it out and determined that both were bad. He sent them out to a guy (Bill Kennedy) to rebuild them and they were returned. Trouble was that after installation both "rebuilt" motors did not function. They tested bad again. Bill offered to make good so he returned them. On the second try the motors worked but he got hit for $28 in extra shipping costs and an additional hour of extra labor. I tell you it takes an expert to rebuild the Gen I motors. They are just so overly complex.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
Update: My left D side motor's gear or output shaft, shown above, finally died last night. (Note that I drive ~1000 miles per year and mostly during daytime last few years now.) I'm guess the shaft because will lift the HL w/ Hood open.
I bought 2 new Cardone motors thru Amazon should be here is a couple days. L is ~$90 R is ~$100 but have 5% back for card used so can be less at the end plus free shipping.
I no longer recommend any Derlin pins. If you keep the car and drive at night... You might get luckly and last years but some only last a few days to months before next weak area breaks and likely means the gear as shown above or the output shaft. I'll post more pictures next week.
Note: Amazon has Dorman dowels/pins a bit cheaper then cheaper then most. Dorman told me type of plastic for them but have to dig thru my old email to find. I think Close to LDPE or HDPE, is not Derlin or any other Nylon formulas. Old and new version are same type but exact formula effects final strength and I think new Clear is a bit stronger but not stronger then the gear plastic.
[This message has been edited by theogre (edited 02-03-2017).]
I think few have ever seen a set of bumpstops intact. Either Genration 1 or 2. Generation 1 bumpstops are shown in one of my posts earlier in this thread. They straddle the ribs inside the plastic gear.
I have a full set of Generation 2 gears from a low mileage wrecked 87GT, I had to rebuild them because one of the motors wouldn't lift the headlight. When I disassembled them, I found that the aluminum clutch portion had spun on the motor output shaft. It's likely pressed onto the shaft during manufacture. Some have drilled through and inserted a pin successfully, while some have told me that after doing that, the shaft or aluminum clutch piece sheered.
When I opened the Generation 2 motors from the 87GT and found the clutch had spun on the output shaft, I also found that the original bumpstops were still in good shape. The material is hard plastic. They have a hole through the core. My theory is that gives them a crush zone in the event that something goes wrong with another part of the system.
The motors will continue to work with crushed bumpstops. At least until all the crumbs vacate the cavities between the clutch and gear. Just yesterday, I opened up a pair of motors that were still operating, yet 1 would continue to spin at the end of it's up or down travel. These motors looked almost new, inside and out. I assume they were aftermarket or rebuilds because they had clear decal part number decals on them.
I've never seen any crumbled bumpstops as clean as these. They looked like fine granulated sugar. Even the color was near white. The grease inside was still just a little darker than Vaseline Petroleum Jelly. They both still worked just because the bumpstop crumbs were still providing enough friction between the clutch hub and the gear.
As TheOgre pointed out earlier. Something too hard will cause another part to break. There is always a weak point in anything mechanical. Personally, I'd rather use something a little softer to absorb shock, have to rebuild from time to time, than to have a part fail that isn't available any longer, or have to go through the trouble and expense to convert to some form of flushmount.
Originally posted by wgpierce: Well, it's always good to know that you can just manually crank the motors up and disconnect them. At least you can still drive your Fiero!!
Only because the shaft had some resistance. Many times shaft will just spin and do nothing even w/ hood open.
quote
Originally posted by fierofool: ... When I disassembled them, I found that the aluminum clutch portion had spun on the motor output shaft. It's likely pressed onto the shaft during manufacture. Some have drilled through and inserted a pin successfully, while some have told me that after doing that, the shaft or aluminum clutch piece sheered.
When I opened the Generation 2 motors from the 87GT and found the clutch had spun on the output shaft, I also found that the original bumpstops were still in good shape. The material is hard plastic. They have a hole through the core. My theory is that gives them a crush zone in the event that something goes wrong with another part of the system.
I betting Metal is cast w/ shaft in the mold and shaft has "ears" stamped to keep traction. I think this because you can't pull shaft out of metal after damage is done. I will take dead shaft apart to see later.
Hard hollow plastic pins are someone else Derlin pins like Eckler's. http://www.ecklerscorvette....r-set-1988-1996.html OEM pins are tanish color and solid and left over pieces feels about like chalk dust to baby powder. Dorman are milk or clear solid pins.
The ones I took out that had white powder may be Dorman. Definitely didn't smell like Columbian.
The ones with center holes from the wrecked 87 were amber. I really believe they were original because of mileage and that it was put in a barn when totaled in 1990.
I think you may be right about the casting because the brass bushing is cast into it. The shaft may be knurled to provide grip and bonding.
[This message has been edited by fierofool (edited 02-04-2017).]
New motors are now in the car. They are noticeably quieter then old motors and not black finish but fits the same.
For the dead one... confirmed shaft just spins. Can turn easy all day w/ a very small wrench to grip the mounting flats for lift link. Took quick look at the gear etc. Gear is same as above and Rodney's dowels still look new. No time to do more, maybe tomorrow.
Posts here and elsewhere tell how tried to fix the shaft (Most fail soon after.) but never find what inside. I have extra parts so I'll see with this one.
I forgot brass on the Output shaft... Might be simple thrust bearing (Because teeth load the shaft axially while rotate the part.) or more complicated. I'm trying to section the pot metal and maybe brass if needed w/o totally destroying it to show exactly how they work together. Maybe a better fix for dead ones too.
[This message has been edited by theogre (edited 04-13-2017).]
Late but as "promised" Driver's side Gen2 HL Motor output shaft sectioned. (Finally had time and weather to work outdoors.) 1.The shaft is just knurled to hold/grip when the Aluminum is cast on the shaft. 2.The brass bearing is only a thrust bearing to handle heavy loads when the motor is lifting the headlight. Higher load because has to push up the doors too but door springs fight that.
CLICK FOR FULL SIZE
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Yes the Shaft is "Weak" but GM made the motor with dowels to fail easier then the shaft. Even plastic gears with Delrin pins can beat the shaft and break it as I did after rotating the gear to give me more time. In my case was ~4 years but I drive ~1000miles/year and mostly during daytime. Many vendors including Rodney sell Metal gears but just mean the shaft will fail and likely soon if you regularly drive at night or in bad weather.
I'm not the only one that have problems w/ Delrin for this use. Several posts over the years with dead output shaft just on PFF. Some have pinning/screwed the shaft parts but many that tried fixing have problems and soon fail again. I betting most have sold or junk the car w/ Delrin pin before having problems.
Dorman told me the pins are "Thermoplastic polyurethane (TPU)." I guess same family/class but different formulas... Old version milky color as posted in that page, new version is clear and some say they're better. In general TPU plastics have Impact strength and are Flexible so they can absorb/buffer the loads as showed above vs Delrin passes all shock and other loads directly from gear to the shaft and other way around.
You're better off to using Dorman pins and deal with the fact they might be "weak" or very likely others things will overload and break them or just use Cardone new motors. If you do have HL lift and/or door problems then even new motors could fail but Cardone have a warranty. Metal gears alone cost ~$40 each but new motors can be as low as ~$90 each and no headaches.
Other notes: Shaft is not hard steel and can be easily cut by the hacksaw used here. In fact was hard not to damage the shaft cutting thru the aluminum. (or worse maybe is pot metal?) Likely I could pry off the bearing to save it but molding flash said the bearing is in the mold too so I cut it. The damaged gear has "healed" itself somewhat likely because the white grease and moving damage area so won't get loaded at end of travel. The cracks show above are there but not so obvious and if I didn't mark them likely couldn't find them now.
(edit to fix images.) ETA 10-2-19 I finally found my Dorman part but won't fit w/o doing something to file/sand them down. IOW Likely Works but not a direct fit. I only bought to have spares on hand so didn't try to file them. Note: This Dorman part is made to fit Ford PW motor & likely fit them w/o sanding.
E2A--> Easiest way to install the Dorman 74410 is... Grab a pin on flat sides w/ pliers then sand off the round side to fit. Small "Water pump" pliers & some other types may hold better. Any power sander w/ 120 to 220 grid works well & doesn't "eat" too fast. Don't use a grinder w/ high RPM. If no power tool available, tape sand paper to a flat surface. They don't need a lot of work. ALMOST fit as is & I just sanded off the factory surface so the gear fit the driver lobes w/o effort. It doesn't matter if you sand & get a minor flat spot(s). Motor will force a flat spot over time w/ door closed & pins stay loaded enough to deform.
Even if OE or Cardone motors break these pins... I'll install these again & check for other problems. Better then buying Any Delrin pins so will break the gear, output shaft or both next time door jams for any reason.
[This message has been edited by theogre (edited 12-29-2023).]
Here's the bearing off... I think the bears is in the mold before casting because of the flow wraps around and in the bearing. Bearing is tight on the shafts but bonded so likely can carefully pry it off and even reverse it if it has wear issues.
The metal maybe pot metal because it melts very fast, like small scraps melt is ~2 seconds and flows easy.
Failures like this are extremely rare. I've seen a few spin on the shaft thru the years. Maybe a few dozen over many many years. I've sold thousands of kits. Firebirds and C4 Corvettes also. If spinning on the shaft was a common problem it would be discussed here on a regular basis. It is not because it rarely happens. At most a handful of people have contacted me thru the years with slipping aluminum pieces. That is Fiero, Firebird and C4 Corvettes combined. C4 Corvettes take a lot more abuse and some (not all that uncommon) actually strip the teeth out of the factory plastic gear. Yet very, very few C4 Corvette owners ever have the aluminum piece strip on the knurled shaft.
------------------ Rodney Dickman
Fiero Parts And Acc's Web Page: All new web page!:www.rodneydickman.com Rodney Dickman's Fiero accessories 7604 Treeview Drive Caledonia, WI 53108 Phone/Fax (262) 835-9575
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or they broke and the customer doesn't want to deal with me again, 
but I like to think they're still working. _3.JPG)
If you keep the car and drive at night... You might get luckly and last years but some only last a few days to months before next weak area breaks and likely means the gear as shown above or the output shaft.
