I'm hoping this should be good enough to twist off the axle shafts. Whatever they can take, these cups should be two steps stronger. The Fiero cups don't fail. The only failures we have seen on this forum were caused by external factors, such as too short an axle (FieroX's w/500HP ish) or a split internal tripod joint. We've seen the longitudinal guys take the fiero cups, cut the shaft off them and weld them to a plate, bolt that to the longitudinal transmission, and not have issues with the cups. 600 horsepower? I don't know if the rest of the axle is up to the task. We are talking about a manual transaxle too, which the axle stresses are considerably higher due to shock loading of the dump clutch nature of a manual shift.
Well, you sure answered my question, thanks. As for the shafts taking it, There are places like the much-malgned Moser, so hopefully my contact patches will be what gives first.
If there's an off-the-shelf combo that works, that would be great. For the amount of effort those custom tri-pots require, it's more efficient to have Moser, etc, make a set of custom axles to mate the F40 inners to the Fiero outers.
If there's an off-the-shelf combo that works, that would be great. For the amount of effort those custom tri-pots require, it's more efficient to have Moser, etc, make a set of custom axles to mate the F40 inners to the Fiero outers.
Yep, it's very reasonable price wise and if you have a couple of axles laying around at least an inch in diameter you can send those in and have them cut and splined appropriately for even less than a set of new axles. Just make sure they get the snap ring groove right.
[This message has been edited by Joseph Upson (edited 07-16-2009).]
I mentioned Moser because they came up before, but in the past I've much preferred Dutchman. I haven't ordered anything in over a year, so I'm not sure they've survived this recession, but it's a great company, a smaller operation than Moser.
Not sure if this has been posted as of yet but here's my attempted contribution to the thread.
These here are the left side o7 SS Cobalt Axles. I can get more measurements for those who need it for about the next week and after that I will not have access to them for about 3 months. These were taken apart to see if there was the possibility of mix matching them with something else that GM makes by NW Driveline to which they have told me that they can not come up with anything that they have access to.
For my application, it looks like I will have to have custom axles made due to the location of where I placed the motor.
--Allen
------------------ Is this where I insert something witty?
I believe the proper way to measure this distance is with the joint installed in the hub and the tripot in the transmission with the car on all four wheels at normal ride height. You should measure from approximately the snap ring groove inside the joint, to the middle insideof the tripot so that at normal ride height the roller bearings are centered leaving plunge room inside the tripot. I didn't go through that trouble. I knew my left inboard joint would be about 1 inch closer to the left side of the car so I aimed for an axle 1" shorter than stock.
Originally posted by Fierobsessed: Take it I am too late to ask for a measurement (?) But... What is the diameter of the rollers in the tripod? and the approximate diameter of the outside of the tripot? If NO, then no sweat, I have my solution, but I am curious about those cups
Sorry FBO -
The movers packed up all the stuff and I just got an E-mail saying that its been delivered to storage.
When I get to it, I will be more than willing to get that for ya.
My G6 is going behind a 3800 SII SC So I am investigating the flywheel/clutch again.
Still having one heck of a time finding the magic number. I've taken many measurements, put it into CAD, and I've come to the conclusion that it has to be about 1.76" thick for the throw out bearing to function within its limited range using a Fiero Pressure plate. Also, the disk's hub has to be slightly biased towards the transmission. The fiero's stock disk hub would just hang over the edge of the spline slightly, so shifting the hub a little more towards the transmission is beneficial. I found that the Fiero's stock disk hub is exactly centered over the available spline shaft on the stock application. CAD helped me through this one.
Does anyone have the known thickness for a 3800 manual flywheel from a F bod? Flange to friction surface of course. I bet its nowhere near what is needed. It seems like the only thing easy about this transmission, is bolting it to the engine.
This is what I am doing, this is the Fbody flywheel from the low mileage engine that I put in my car. I am moving but dug it out for you to take some pictures. They did not come out good but you can see no tape used and only precision instruments to take my measurements. The flywheel is not clean and has some rust from being out. I will use it for a core. The flywheel is 1.960 from clutch surface to crank surface with the surface rust. I will be using this with my fiero pressure plate it is new and was not cheap so I will only need to get a new disc.
I have some, nearly set in stone values for the thickness of the flywheel... At (approximatly) 1.65", the throw out bearing may not be able to release the clutch without topping out. (still need to verify this one) At 1.87", the Throw out bearing will bottom out each time you let the pedal out. At 1.93", the clutch contacts the insides of the transmission.
So it looks like 1.75-1.80" should be good. I'm still researching.
Does anyone know how much travel at the throw out bearing is needed to disengage the clutch? I havn't found a good number for this yet.
I have some, nearly set in stone values for the thickness of the flywheel... At (approximatly) 1.65", the throw out bearing may not be able to release the clutch without topping out. (still need to verify this one) At 1.87", the Throw out bearing will bottom out each time you let the pedal out. At 1.93", the clutch contacts the insides of the transmission.
So it looks like 1.75-1.80" should be good. I'm still researching.
Does anyone know how much travel at the throw out bearing is needed to disengage the clutch? I havn't found a good number for this yet.
Two important measurements that should be taken and that I regret not taking is of each flywheel clutch and pressure plate assymbly bolted together, from the bottom of the flywheel to the top of pressure plate release flanges and the top of the disc's spline bore.
From mounting flange surface to clutch friction surface the G6 flywheel is 1.62" thick.
[This message has been edited by Joseph Upson (edited 08-07-2009).]
Good # to know. There is a bit of a grey area when it comes to clutcthes. I know that as clutches wear, the fingers start to grow outwards from the pressure plate. How much? I have no Idea. I also have no idea how much Throw Out Bearing travel it takes to release the clutch, Its probably only about 0.25" or so. The TOB on the G6 only has 0.54" of travel available. So positioning the surface of the clutch is critical or you will run out of stroke. I am guessing that when the clutch is new, the TOB is probably closest to its most extended limit when the pedal is pressed. The Getrag's slave had about 0.71" of useful stroke, so it was a bit more tolerant. But knowing that the F bod flywheel is 1.96" thick, means its good to go, just needs some surfacing. Im still hoping that the ring gear is the correct size, but I'm skeptical. Now If only I can remember to call SPEC, and inquire about the SC82A Aluminum 3800 Fbod flywheel... It looks like a potential problem solver, but might require some lathe time to correct the thickness.
I haven't pulled the HTOB on the F40 to confirm, but if you are concerned with maxing out the throw of the HTOB, you should be able to shim the backside of the HTOB to move it closer to the pressure plate fingers (I did this on my 92-94 HTOB getrag).
Good # to know. There is a bit of a grey area when it comes to clutcthes. I know that as clutches wear, the fingers start to grow outwards from the pressure plate. How much? I have no Idea. I also have no idea how much Throw Out Bearing travel it takes to release the clutch, Its probably only about 0.25" or so. The TOB on the G6 only has 0.54" of travel available. So positioning the surface of the clutch is critical or you will run out of stroke. I am guessing that when the clutch is new, the TOB is probably closest to its most extended limit when the pedal is pressed. The Getrag's slave had about 0.71" of useful stroke, so it was a bit more tolerant. But knowing that the F bod flywheel is 1.96" thick, means its good to go, just needs some surfacing. Im still hoping that the ring gear is the correct size, but I'm skeptical. Now If only I can remember to call SPEC, and inquire about the SC82A Aluminum 3800 Fbod flywheel... It looks like a potential problem solver, but might require some lathe time to correct the thickness.
The pressure plate cover positioning is a must know before the 3.4 or 3.8 flywheel gets the okay, the F40 pressure plate has an extended friction hub instead of being flush with the pressure plate cover mounting flanges like those found on the Fiero p-plate cover. You may be able to see this difference in the pictures I posted early in the thread. In other words there could be an exceptional difference in the location of the p-plate release flanges between the two clutch assymblies once installed.
[This message has been edited by Joseph Upson (edited 08-08-2009).]
I saw that someone posted a question about using the Fiero master (clutch) clyinder with the F40 HTOB, and are they compatible, but at the time, the question wasn't answered as there were larger issues.
I am currently testing the MR2 clutch master cylinder with my F40 HTOB, and after creating a test rig, where the HTOB can push on a spring, it appears that the they are not compatible. I am not totally sure yet, it could be air in the system, or it could be that the bore is fine, but the stroke is not enough, so it doesn't move enough volume of fluid.
The MR2 master is 5/8" diameter bore.
What is the Pontiac G6 GTP 3.9L master cylinder bore and stroke?
I have a new master cylinder assembly from Napa that was meant for the Pontiac Gran Prix 2.2L. I bought it because it has the F40 HTOB compatble plumbing fittings. The bore on this master is .530 inches
What are the guys with running/driving Fieros with F40's using for the master? What is the bore and stroke of this master?
I haven't pulled the HTOB on the F40 to confirm, but if you are concerned with maxing out the throw of the HTOB, you should be able to shim the backside of the HTOB to move it closer to the pressure plate fingers (I did this on my 92-94 HTOB getrag).
I do not believe you can do this with the F40 HTOB. The trans input shaft seal is integral to the HTOB, and shimming it would cause the backside of the HTOB to not be sealed to the trans, and you would lose all of your gear oil. It would go into the bellhousing area and probably ruin your clutch as well.
Good # to know. There is a bit of a grey area when it comes to clutcthes. I know that as clutches wear, the fingers start to grow outwards from the pressure plate. How much? I have no Idea. I also have no idea how much Throw Out Bearing travel it takes to release the clutch, Its probably only about 0.25" or so. The TOB on the G6 only has 0.54" of travel available. So positioning the surface of the clutch is critical or you will run out of stroke. I am guessing that when the clutch is new, the TOB is probably closest to its most extended limit when the pedal is pressed. The Getrag's slave had about 0.71" of useful stroke, so it was a bit more tolerant. But knowing that the F bod flywheel is 1.96" thick, means its good to go, just needs some surfacing. Im still hoping that the ring gear is the correct size, but I'm skeptical. Now If only I can remember to call SPEC, and inquire about the SC82A Aluminum 3800 Fbod flywheel... It looks like a potential problem solver, but might require some lathe time to correct the thickness.
I beleive you can make a good guess as to how much the diaphram fingers move as the clutch disk wears.
Here is what I did: I sandwiched an area of my clutch disk between some wood, and used a C clamp to squish the disk. Some disks are springy and can be squished by the PP when it is tightened down, so I simulated this with the wood and C clamp. Next, I looked for the areas of the disk that would end up being the thinnest when it is fully worn out. FOr example, on a normal disk with organic full faces on both sides, you measure the full thickness with calipers, then use the depth end of the caliper and measure how far down the rivet heads are below the surface of the friction face. YOu subtract that (the rivet head depth from each side of the disk) from the total thickness, and that number is the fully worn out disk thickness.
Now, you find some washers or shims or whatever you have handy that cannot be squished by a lot of pressure (I stacked up large diameter washers with the right thickness), and will not damage the friction surface of your flywheel and PP. With the flywheel off of the engine, you place the washers on the flywheel at regular intervals. THen you place the PP on top and tighten it down. Now you can measure the location of your diaphram fingers. I used the surface of the flywheel as my reference. I used a machinist straightedge laying across the fingers. I used digital calipers to take this measurement.
I did the same with the disk and the PP installed as they would be normally. In this situation, the diaphram fingers are usually below the top surface of the PP, so you have to measure using the depth end of the caliper. Now you have the total distance the fingers move as the clutch wears.
It helps to make sketches of both situations. Now to complicate things, you will need to figure out how far the fingers need to move to RELEASE the disk. On this one, I am not sure. I am using about .03 - .05inch gap total between the disk and one friction surface as my guess as to how far the PP needs to move to fully release the disk. To simulate this, you place the disk on the flywheel, then some washers that are .03inch thick (or use shim metal--they sell thin aluminum plates at the hobby shop) on top of the disk, then bolt the PP into place, and measure the diaphram finger locations. THis is, of course, with the disk with no wear at all on it. However, the distance the fingers need to move to disengage won't change as the disk wears. Its only thier starting location (determined above) that changes.
[This message has been edited by CBulen (edited 09-24-2009).]
I didn't do any of that. I just connected the Fiero Mastercylinder which has to much volume and installed the retaining nuts a safe distance on the studs without securing the mastercylinder flush against the firewall. In other words there is a gap between the firewall and mastercylinder to prevent full piston travel and reduce throwout bearing travel. It works well enough to allow me to forget that I need to figure out something a bit more tact later.
I'm making a few spacers out of steel plate. so far I've made 3 out of 1/8" and will make more if needed. The plate lets me spread the load out over more of the firewall to reduce flex and improve response. It'll work better once I make a brace for the inside, but best of all would be a new, thicker firewall.
Can anyone help with my above questions? I am going to have to purchase an aftermarket master cylinder, and need to know bore and stroke of the G6 clutch master to size the aftermarket one.
I just did a test with my F40 HTOB in a rigged up test frame. The Pontiac grand am 2.2L clutch master cylinder moves the F40 HTOB about 6mm
[This message has been edited by CBulen (edited 09-24-2009).]
You mentioned that you've used a 92-94 HTOB with your Getrag - do you have details/pics/writeup on it?
quote
Originally posted by fieroguru:
I haven't pulled the HTOB on the F40 to confirm, but if you are concerned with maxing out the throw of the HTOB, you should be able to shim the backside of the HTOB to move it closer to the pressure plate fingers (I did this on my 92-94 HTOB getrag).
You mentioned that you've used a 92-94 HTOB with your Getrag - do you have details/pics/writeup on it?
I am running a FWD 92-94 Getrag with the HTOB designed to go with it (haven't tried swapping the HTOB into an earlier Getrag case - don't have any Fiero Getrags) https://www.fiero.nl/forum/Forum2/HTML/091336.html
It looks like the neutrally balanced manual flywheel from the camaro/firebird will be the easiest approach to get around the dualmass flywheel. I believe F355spider measured the flywheel height to the top of the piece of metal he has on top of the flywheel in the picture he posted. I just picked up an example flywheel and measured the following:
I measure a height of 1.738" vs. the dualmass flywheels 1.62" leaving a difference of .118". since there is cushion designed in the clearance the entire .118" should not require removal. The pressure plate bolt pattern is different than that found on the dualmass flywheel as far as spacing goes, I'm not sure how it compares to that found on the Fiero pressure plate but hopefully tomorrow I'll stop by a store in an effort to get a measurement. I'm not sure if the camaro pressure plate release flanges will be at the proper height to use it instead of having new pressure plate holes drilled. The ring gears as you can see between the G6 flywheel and Camaro FW mesh when both are facing upward. The camaro ring gear has 148 teeth vs the Fiero flywheels 142 so the ring gear mounting surface will need to be turned down. 142 tooth gear ID= 10.978", internal underside diameter of the camaro flywheel = 11.088 leaving .110" + a little for tight fit. It will also need a few tack welds for added security as the underside of the flywheel has shallow radiused voids around the inner perimeter so the tack welds can be placed in a few of those before balancing.
I'm still trying to get the measured height of a Fiero flywheel, clutch disc and pressure plate bolted together but it appears I'm the only one that has a set of those parts laying around except 500 miles away from me at the moment however, so if someone can find the distance between the flywheel mount surface and the pressure plate release flanges with the assembly bolted together that would help. I'm still biding time between my studies and play so there's still a couple of months ahead before I can get back to my project. Progress will be slow until then.
[This message has been edited by Joseph Upson (edited 01-06-2010).]
Originally posted by Joseph Upson: The camaro ring gear has 148 teeth
When you get a chance, can you measure the OD of the camaro ring gear... just curious if it would fit within the F40 bellhousing. If so, it would provide more freedom for those of us working on a tranny mounted starter.
When you get a chance, can you measure the OD of the camaro ring gear... just curious if it would fit within the F40 bellhousing. If so, it would provide more freedom for those of us working on a tranny mounted starter.
12.429"
Will it fit?
[This message has been edited by Joseph Upson (edited 01-06-2010).]
Nope... 12.30 ID on the F40. There is one boss that protrudes into this so the clearance is actually less, but if 12.30 would allow it to fit, that boss could be clearanced.
Nope... 12.30 ID on the F40. There is one boss that protrudes into this so the clearance is actually less, but if 12.30 would allow it to fit, that boss could be clearanced.
Well, the ring gear tooth depth is .167", the diameter would need to be reduced by .129" to get to 12.3" max dia, so you would have to turn the ring down by at least .0645" plus additional necessary clearance for the bellhousing so lets say .0655" leaving you with .167" - .0655" = .1015" gear tooth height. It would work well with a tight clearance gear mesh. I might even try cutting my ring down first just to see the outcome.
On second thought, I'll just install the smaller ring gear. Can you measure the depth from the bellhousing mounting surface down to the fully compressed throwout bearing in the F40, I can use that measurement as an alternative to the Fiero clutch assembly to estimate clearance.
[This message has been edited by Joseph Upson (edited 01-06-2010).]
Ok I havent read through the entire thing, but seeing how I've gone through similar clutch woes with my ecotec swap I thought I would chime in.
It seems that the clutch issue looks like its wayyy overcomplicated than it should be. The clutch/pressureplate/flywheel shouldnt be nearly as difficult as everyone is making it out to be, a custom shop should be able to make a clutch with the correct spline count, then whatever flywheel for the engine you want, the only thing to worry about is where the F40 engage/disengages the TB to the pressure plate in stock configuration, as long as the new setup is close to that, there shouldnt be any problems.
Am I missing something? I mean I took alot of measurements to do mine, but this just seems way overcomplicated for something simple.
Ok I havent read through the entire thing, but seeing how I've gone through similar clutch woes with my ecotec swap I thought I would chime in.
It seems that the clutch issue looks like its wayyy overcomplicated than it should be. The clutch/pressureplate/flywheel shouldnt be nearly as difficult as everyone is making it out to be, a custom shop should be able to make a clutch with the correct spline count, then whatever flywheel for the engine you want, the only thing to worry about is where the F40 engage/disengages the TB to the pressure plate in stock configuration, as long as the new setup is close to that, there shouldnt be any problems.
Am I missing something? I mean I took alot of measurements to do mine, but this just seems way overcomplicated for something simple.
Axles.... Im confused there
There's a lot in the thread that you are missing. The current subject is all about measurements without which you can't perform a proper combination no matter how simple it appears. This is about replaceing the stock dualmass flywheel with a substitute that is not a direct fit, if you don't know the measurements that I've inquired about you can't possibly know how much work needs to be done to the replacement flywheel. The clutch itself was resolved on page 1 or 2. Read back a little further and that will put you on track with what's going on.
[This message has been edited by Joseph Upson (edited 01-06-2010).]
Ok I havent read through the entire thing, but seeing how I've gone through similar clutch woes with my ecotec swap I thought I would chime in.
It seems that the clutch issue looks like its wayyy overcomplicated than it should be. The clutch/pressureplate/flywheel shouldnt be nearly as difficult as everyone is making it out to be, a custom shop should be able to make a clutch with the correct spline count, then whatever flywheel for the engine you want, the only thing to worry about is where the F40 engage/disengages the TB to the pressure plate in stock configuration, as long as the new setup is close to that, there shouldnt be any problems.
Am I missing something? I mean I took alot of measurements to do mine, but this just seems way overcomplicated for something simple.
Axles.... Im confused there
This is the largest problem... the splines on the input shaft are deeper into the tranny than any other fiero manual tranny... so you must somehow move the clutch disk (and its splined hub) further from the crankshaft flange so it will properly mesh with the recessed input shaft.
The secondary issue is the HTOB has a limited amount of stroke unlike the stock fiero transmissions. So the clutch pressue plate fingers must operate in the same range of motion which is from 2 5/8” to 3 3/16” from the bellhousing face.
A stock fiero depth flywheel (about .81" from the bellhousing flange) will not provide full mesh to the clutch disk splines nor will it put the pressure plate fingers in the range of motion for the HTOB.
The current DIY trend is to start with a RWD flywheel (they are thicker) to help get the clutch/pressure plate combo deeper in the transmission where it needs to be.
Fieroguru your measurement for the F40 depth suggests one of us is off on the measurement, I measured the stock G6 flywheel and clutch assembly on page 1 to be 3.33 with an additional clearance that I estimated necessary (I'm not sure anymore exactly) but my measurement has to be more accurate since the stock assembly would not fit otherwise unless the crankshaft flange is actually recessed a little relative to the engine block bellhousing surface. I also recall the 5 speed input shaft sticking out a little passed the bellhousing. I used a digital caliper I picked up from Harbor Freight to measure.
[This message has been edited by Joseph Upson (edited 01-06-2010).]
