Ok, so... I'm planning for the restoration of my 1987 Pontiac Fiero, as soon as my daughter's car is out of the garage.
As I'm writing this, there are two minutes left on an auction where I'll essentially be buying an Oldsmobile Achieva W41 SCX 5-Speed Getrag.
Now, I already have 2 5-Speed Fiero Getrags... one that has super low miles... like 30k, which I got from Blacktree or someone else (can't remember), and another 5-Speed Getrag which has 130k miles on it, and is seriously ragged out. The case itself though is SOLID, and everything spins.
Since I know the Olds Achieva Getrag uses a different bell-housing, can I simply swap out the bell-housing with the one from the Fiero Getrag?
For the record, I'm going to attempt to rebuild it myself, entirely (yes... I know... I can't do it, blah blah, get a professional).
I took apart my daughter's spare 5-Speed Isuzu, and that looks less complicated than rebuilding an automatic, so I think I can do it.
Any advice... do you guys know where I can get a solid rebuild kit? (new bearings, etc.)?
Last question can I literally swap out all of the Getrag stuff from the Achieva into the Fiero's transmission case? Or is that defeating the purpose of what made the W-41 Getrag special?
I know the gearing is different... from what I understand, the final drive ratio of the Olds Achieva Getrag is 3.91:1, with a better (higher rpm) 3rd and 4th gear.
Thoughts? (Keep in mind, I want to keep the car as stock looking as possible with my 3.4 swap).
That looks like a 92 transmission, so it could be one of the HTOB transmissions from 92-94. If it is, then one of the shift shaft rails will be shorter than the non-HTOB getrag.
To make room for the base of the HTOB, the case is shallower and took up some space for one of the shift rail bosses.
Originally posted by 82-T/A [At Work]: I know the gearing is different... from what I understand, the final drive ratio of the Olds Achieva Getrag is 3.91:1, with a better (higher rpm) 3rd and 4th gear.
Thoughts? (Keep in mind, I want to keep the car as stock looking as possible with my 3.4 swap).
Gearing-wise, it's kind of like the 84 M19 4.10 Performance transmission, so if you liked that, then I think you'll like the SCX gearing.
I've got a "converted" Quad 4 Getrag in my GT. I also have a spare of the identical trans. (I think the code is FDDC or something like that. Info that I've found indicates that it may have come from a European minivan application.) The un-converted spare is, indeed, the HTOB version. I really like how it feels, bolted to a 2.8. The gear spacing just seems... "right".
To directly address your question, I have never taken a Getrag apart (other than the really tired one that I blew up, leaving a club meeting.) But I understand they require a number of specialized tools, jigs, and other things. Be careful, and good luck.
Originally posted by Raydar: To directly address your question, I have never taken a Getrag apart (other than the really tired one that I blew up, leaving a club meeting.) But I understand they require a number of specialized tools, jigs, and other things.
Taking them apart is pretty easy... setting the bearing preload on assembly is the critical step for longevity.
Taking them apart is pretty easy... setting the bearing preload on assembly is the critical step for longevity.
Ah. Okay. I was (I think) thinking about removing/reinstalling various shafts, full of gears. But yeah. I suppose that setting the bearing preload is a bit daunting if you've never done it. Which I haven't.
[This message has been edited by Raydar (edited 08-20-2024).]
Thanks guys, I appreciate it. Sorry I didn't respond earlier, I was away on business.
I have three Getrags total... one which has 30 some odd k which I don't want to mess with, but a rather tired and worn out one, which I want to essentially use with this SCX one to make the "ideal" Fiero Getrag I suppose.
You guys mentioned about it feeling like a 4.10:1... I know the difference is essentially a .3 in the final drive. It's a 5-Speed of course, so will I still be able to drive on the highway and not have my engine screaming if I'm cruising at 70 miles an hour? What would the RPM be, effectively, at 70 miles an hour?
Anyone know where I can buy a proper rebuild kit, or is there a Getrag manual? Thanks guys!
There are two gear reductions in a transaxle like the Fiero uses.
The first reduction (or overdrive) is in the speed gear.
The second reduction is in the final drive, and applies to all speed gears.
You should calculate the total reduction (which is the product of both ratios) if you want to make meaningful comparisons between different transaxles.
Example of total reduction calculation for M19 Muncie:
2nd speed gear ratio = 1.95 Final drive ratio = 4.10
Total reduction in 2nd gear = 1.95 * 4.10 = 8.00
Tabulate this information for all gears for the transaxle alternatives you are considering, then you should be able to better compare things.
Do these RPMs seem reasonable for highway driving? I'm just curious because I seem to recall in cars like my Crown Victoria, which only has a 4-Speed automatic... at ~65, it's basically barely pulling 1,500 rpms with a 2.73:1 final drive. So ~3,000 rpms seems a bit aggressive. I'm just wondering if that's significantly more than what would be reasonable... hah...
quote
Originally posted by pmbrunelle:
There are two gear reductions in a transaxle like the Fiero uses.
The first reduction (or overdrive) is in the speed gear.
The second reduction is in the final drive, and applies to all speed gears.
You should calculate the total reduction (which is the product of both ratios) if you want to make meaningful comparisons between different transaxles.
Example of total reduction calculation for M19 Muncie:
2nd speed gear ratio = 1.95 Final drive ratio = 4.10
Total reduction in 2nd gear = 1.95 * 4.10 = 8.00
Tabulate this information for all gears for the transaxle alternatives you are considering, then you should be able to better compare things.
RGR, thank you! This makes perfect sense. I always wondered exactly how the individual gears vs. the final drive gearing worked.
Do these RPMs seem reasonable for highway driving? I'm just curious because I seem to recall in cars like my Crown Victoria, which only has a 4-Speed automatic... at ~65, it's basically barely pulling 1,500 rpms with a 2.73:1 final drive. So ~3,000 rpms seems a bit aggressive. I'm just wondering if that's significantly more than what would be reasonable... hah...
Thanks!
It's a little fast, but keep in mind that the regular Getrag will provide ~2400 RPM at 70 MPH. So, the Quad 4 version is another ~500 RPM. Still feels really good in the car.
It's a little fast, but keep in mind that the regular Getrag will provide ~2400 RPM at 70 MPH. So, the Quad 4 version is another ~500 RPM. Still feels really good in the car.
I got it the day before I left for a business trip. But I got back yesterday and opened it up this morning. The thing is in really nice shape, and I'm pretty excited, honestly... really looking forward to rebuilding it. I have to try to find a rebuild kit... assuming I probably only need new bearings. But I've never taken apart a manual transmission before (I mean, other than the spare 5-Speed Isuzu I had). So, I'm hoping I can make one really solid one from the spare I have, along with this Oldsmobile one.
Honestly, I know I won't be driving this car long distances, really... so I shouldn't be too concerned if my highway speed is that bad.
How do you decide what is a “good” overall reduction in top gear?
Ability to climb a slight grade without downshifting?
Fuel consumption is ok?
Oil consumption is ok?
Exterior noise level is ok?
Noise level in cabin is ok?
How do you decide what is a “reasonable” cruising RPM? What does reasonable mean?
That's a fair question.
For me personally, it means that the engine is not "struggling" at "cruising speed" while on the highway (which I consider to be ~65-70 mph). And as for "not struggling," I'm kind of biased with modern cars (even my old Explorer has a 5-speed automatic), where it's doing 1,600 rpms at 70 miles an hour.
I'd love to know if I could take 4th and 5th gear from a normal Getrag, and use those with my rebuild in the SCX rebuild... if that's even possible? It has a "better" gear ratio for highway driving.
Living in Florida, you pretty much have to get on the highway if you want to go anywhere other than around town. When I live JUST in Fort Lauderdale, it's fine. ~3,000 rpms seems a bit high for 5th gear at 70. But I'll see what I can do. I'm sure that I'll much more enjoy the acceleration than I will be concerned with highway RPM.
Ok, so... on my way home from picking up a spare cradle and V6 engine (so I can begin rebuilding my 3.4), I also picked up a spare 5-Speed Getrag from my storage unit. It's one that I pulled out of a 1987 Fiero SE / V6 that came from an auction. (Tangent) It was a badass 87... had no options except WS6, and was an SE. Hardtop, 5-Speed, V6, and other than the SE package, had literally no options in the car. When I got it, the previous owner had taken the nose and rear bumper, and the ground effects to upgrade his 4 cyl. The engine in that car had thrown a rod (or something). Anyway... 17 years later, I'm looking at the transmission and drain the oil, it's very clean... and the transmission is in a hell of a lot better shape than I remember it.
I plan to take the SCX Getrag and combine it with the Fiero's Getrag. The SCX is of course set up for a Quad-4, and I'll need to swap out the bell-housing. I've already purchased all of the Getrag upgrades from Rodney (though it doesn't even look like I need them).
So here are my questions:
1 - Where is the best place (or any place) to buy a "rebuild kit" for my Getrag 5-Speed? I found this link in search: https://www.drivetrain.com/...82-fwd-overhaul-kit, but I'm not sure exactly what I should buy... I'm probably going to e-mail them, but am interested in others who have attempted this.
2 - Is there an optimal solution to combining these transmissions... e.g., keep the SCX transmission body and just swap the bell-housing from the Fiero MG2, or do I swap out the internals from the SCX entirely and put it into the Fiero's MG2... thus reusing the entire case from the Fiero transmission?
3 - Is it possible to keep the 5th gear from the MG2 and use it with the gears from the Oldsmobile SCX? My only thought is that this disrupts the rpm range for shifting from 4th to 5th. For anyone who's bored, these are the gear ratios between the Quad-4 SCX transmission, and the standard Fiero Getrag:
Ok, I found the MR10 Synchro Kit from Cobra Transmissions... $100.83 shipped.
I then ordered the Overhaul kit separately from Transmission Parts Distributors... for $72.93
Total was about ~$173 for both. I essentially have everything in this picture here:
In y'alls opinion, is there anything you think that I'm missing here?
It should be self explanitory... I've taken apart multi-complication Swiss movements with parts that are so tiny they make Lincoln's nose on the penny look huge. So I should have no problem with this. My "assumption" is that most of the SCX and Fiero transmissions will be identical inside...
I will take a lot of pictures as I disassemble it, and refer to the Getrag manual that I bought...
I also picked up a spare 5-Speed Getrag from my storage unit. It's one that I pulled out of a 1987 Fiero SE / V6 that came from an auction. Anyway... 17 years later, I'm looking at the transmission and drain the oil, it's very clean... and the transmission is in a hell of a lot better shape than I remember it.
If it was me... I'd just use that transmission as is, and forgo all the messing about with rebuilding and "combining" transmissions.
If it was me... I'd just use that transmission as is, and forgo all the messing about with rebuilding and "combining" transmissions.
I have a very low mileage 5-Speed Getrag in storage (still in a crate) that I can use if I totally screw this up. But I want to make use of the SCX W41 Getrag's gearing. Plus, it'll be a learning experience for me anyway. I can afford (as in non-monetarily) to try to combine the two and make a "perfect" SCX Fiero Getrag since I have a couple of spares.
Originally posted by 82-T/A [At Work]: 3 - Is it possible to keep the 5th gear from the MG2 and use it with the gears from the Oldsmobile SCX? My only thought is that this disrupts the rpm range for shifting from 4th to 5th.
I think that you should keep the SCX 4th together with the SCX 5th, or use the Fiero 4th with the Fiero 5th, to avoid an awkward gap between 4th and 5th.
For those that prefer a stick shift Fiero, it looks like the time to buy a spare and put it away has come. I read that only 1.7% of all new cars sold have manual transmissions. In NJ where I reside you would have trouble finding good used Getrags and when you do the prices are like $1000. Here is the trend:
------------------ " 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, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, 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 "
[This message has been edited by Dennis LaGrua (edited 10-10-2024).]
Originally posted by Dennis LaGrua: For those that prefer a stick shift Fiero, it looks like the time to buy a spare and put it away has come
We have passed that point a while ago. In my area, Getrag 282 and Muncie 4-speed transmissions are essentially no longer available.
Part of the reason why I'm converting to a Getrag F23 is that they are still relatively plentiful, but even then, I will probably buy a spare, just in case.
Thanks guys, I'm messing with it because this is my "dream Fiero" aka... literally my first car. The very car I drove in high school and I've kept it all these years. So I want to make it an absolutely perfect Fiero that had all the options mine missed (mine was originally an automatic, and I'm converting it to a manual), and added all the other options like power door locks, etc.
But I want it done right, and I want it to look stock while also giving me the absolute best performance I can get without changing the "feel and sound" of the car too much. I realize going from a 2.8 to a 3.4 is going to be different from stock, and going with a factory 1-7/8ths aluminzied exhaust to a 2.25" stainless steel exhaust is also different (though I'm keeping the factory tips)... it's enough that I want to make the car more modernly drivable while retaining what I remember about it.
I'll say though, I sat in it last weekend when I was up there getting my other Getrag transmission, and holy crap... getting out of that Fiero is much different than it was when I was 19 (when I basically stopped driving it). As an (almost) 47 year old man... haha... I have to ask myself... WTF... what exactly has changed at 47 that was different when I was 19? Why was it so much easier getting out of the car then? Haha...
quote
Originally posted by pmbrunelle:
I think that you should keep the SCX 4th together with the SCX 5th, or use the Fiero 4th with the Fiero 5th, to avoid an awkward gap between 4th and 5th.
RGR, thank you. I will absolutely do that.
Stupid question though, if you don't mind. Would this not create an awkward gap between 3rd and 4th (say, if I kept the 1/2/3 from the SCX, and 4/5 from the Fiero)? Or is the gap less pronounced between those two gears? What you say makes sense though completely... honestly, 4th and 5th gear to me would be more highway and normal driving gears.
Thank you!
[This message has been edited by 82-T/A [At Work] (edited 10-10-2024).]
Originally posted by 82-T/A [At Work]: Stupid question though, if you don't mind. Would this not create an awkward gap between 3rd and 4th (say, if I kept the 1/2/3 from the SCX, and 4/5 from the Fiero)? Or is the gap less pronounced between those two gears? What you say makes sense though completely... honestly, 4th and 5th gear to me would be more highway and normal driving gears.
In both the SCX and Fiero, the 3rd gear is the same, so using a Fiero 4th with any 3rd would result in a 3-4 gap just like that of a stock Fiero.
You should calculate and tabulate total reduction ratios and the gaps yourself, and come to your own conclusions.
I think that ratio recommendations based on posters personal preferences are not so useful, when ideal gearing in your car is a matter of your own preferences.
You should calculate and tabulate total reduction ratios and the gaps yourself, and come to your own conclusions.
I think that ratio recommendations based on posters personal preferences are not so useful, when ideal gearing in your car is a matter of your own preferences.
Thanks, I'll do that. I think I need to do a bit more research on what I can expect from this motor. I plan to take it to the machine shop, and have them balance everything significantly more than I otherwise normally would. But I also need to make sure that my H272 cam properly matches what I'm expecting from the heads and transmission gearing.
Either way, I may just end up taking the final drive from the SCX transmission.
quote
Originally posted by Patrick:
On level ground, city driving up to/including 4th gear is normal/common.
With a 5-spd transmission, if there needs to be a "gap", I'd definitely want it between 4th and 5th as opposed to between 3rd and 4th.
You're right, but when I looked at the gear ratios that I posted above, and read PMBrunelle's response, I realized they are in fact exactly the same, haha... so it wouldn't really matter.
It seems that all I really want out of this then, is the final drive gear.
