The TCC failed in my 84 V8 the other day . . and though it is now disconnected, the tranny vibration indicates that the converter itself is damaged as well. Now faced with the cost of repairing the stock automatic, should I simply replace it instead? AT or Manual?

I have not liked the V8/TH125C combination, as the engine torque curve does not match the shift points well. So now seems the time to make a change.

The engine is a relatively mild 350, and the car is not a daily driver. Seems that the manual would be more fun, but I don't know what is involved in this change, and maybe a newer 4spd AT would be OK?

If I change to a different AT, which should I use? And if I change to a 5spd, should I use the Isuzu or the Getrag? And which clutch with either of these?

Thanks for your opinions

I currently have a 4 speed with my V8 - all the way from MD to WA I was reaching for a 5th gear at about 70mph. I'd like to swap in a 5 sometime. The Getrag seems to be the tranny of choice on here. And the manual vs. auto controversy - my feeling is you haven't DRIVEN a Fiero until you've driven a manual shift. Worlds of difference between my original '84 automatic and my '85 5 speed (both 4 bangers).

Vic

------------------

'86 GT on the road for the summer!
'85 SC running smooooth.
'86 Gold SE V8 - can you say POWER?

Fiero to the Max!

I believe that we are talking about transmission strength in this post.
Face it, for high power applications all Fiero transmissions are light duty. The TH-125H can be built to take quite a bit more power ( nearly bulletproof) but this involves installing larger bands, additional clutches, a shift kit and a higher stall speed torqueconverter. Jims Performance Transmission (JPT) in the Lansing Michigan area has been building these high strength TH-125H race automatics for years. I have one in my Fiero and it shifts hard and strong. There is no "comfort" slippage at all. In as muchh as my tranny is holding up to the power of my turbo engine I do think that more gears are better. The 4T60 transmission used on many 3800, 3400 and 3100 engined GM cars is pretty tough and offers four speeds. It's a difficult swap as you'll need to change axels but this tranny is quite strong.
I would forget about the GETRAG with a V8 or high power application. As far as sticks go the GETRAG is flimsy. It has a small input shaft which turns on light needle bearings. It's narrow gears will survive 250 ft lbs of torque but if you race with that tranny and a v8 I guarantte it won't last long.
Now get ready for the classic answer sure to be posted next "well I've been using a GETRAG with my V8 and have had no problems" I will simply say to those with blind faith in this gearbox; do you race? If so don't flame, just wait and see for yourself!
Used for it's intended application the Getrag is a great tranny. Used with a V8 -IT'S WEAK, VERY WEAK.

------------------
87GT 3.4 Turbo Best 0-60 5.2 seconds
http://turbofiero.fierojoe.com/turbo.htm

I'm fascinated by this 4T60 transmission. Does anyone know if it has the same internal plumbing as the 4L60 ?

GM uses the T for transverse (sideways).. As in the FWD cars and L for longitudinal (fore/aft).. As in the RWD cars.

If the 4T60 has the same internal workings, as the 4L60, it would be an ideal tranny..

They used the 4L60 in the Corvette, Firebird & Camaro with the 240 - 300 horse, 360 ft/lb TPI & LT1 engines. They can be built to handle over 600 HP..

Just out of interest, the 4L60 was previously known as the TH700R4.. The designation changed to 4L60 in 1990..

Unfortunately the auto isn't a good solution for stick lovers...

------------------

1988 Fiero Coupe 2.5L
1990 Trans Am GTA 5.7L

The 4T60's and the 4L60's are not the same at all. It's not like the 425's and 400's where GM just turned everything 180 degrees and put a chain drive in it and a pumpkin at the tailhousing.

There are a few things that really need beefed up if your connecting a high po motor to a 4T60. Mainly the drive shell needs to be upgraded to a hardened shell. These are prone to breaking anyways.

Dennis - I don't race, I barely DRIVE!

quote Originally posted by Dennis LaGrua: Getrag is a great tranny. Used with a V8 -IT'S WEAK, VERY WEAK.

Here we go again,, Hasnt this subject been beaten to death already in the past?.. I still havent heard of or seen any evidence of 5 speed Getrag tranny failures. Only thing Ive read about is CV and clutch failures.. ANYONE here want to tell us about there Getrag failure with a V8? if so please tell us when and how it happened.

Here's my list of strongest to weakest!
4 spd Muncie
5 spd getrag
5 spd Isuzu
I have driven the GT 4 spd w/V8... As Max Stated "always reaching for 5th"! The 5 spd Getrag is 'Gold'...very expensive, somewhat hard to find! I now have an Isuzu with a mild 350(300hp). I have no complaints at all. 5th lowers the RPM to reasonable cruising at less than 80mph. Isuzu runs on GM Syncromesh, much nicer shifting, almost like I didn't have cables! As far as 'Dennis's' complaint of a Getrag, I would state simply "I was an FIM(world) licensed motorcycle racer(4cyl 2 stroke Yamaha's). I, am not a mild driver, and I have yet to kill even an Isuzu).
All that to say, for the price, an Isuzu can do the job, except for maybe +450hp!!!
Sandy

quote Originally posted by Dennis LaGrua: all Fiero transmissions are light duty. ........ -IT'S WEAK, VERY WEAK.

I have been running the same 4 speed in my 6.6 litre v-8 since 96 with ZERO problems. well over 100 quartermile passes and countless stop light encounters with the 5 litre crowd. I have no experiance with the other trans but I can certainly recommend the 4 speed.

------------------
86 SE, 88 front and rear suspension, 6.6 Liter EFI SBC, RaceTech ECU,Subframe Connectors, Poly Bushings,17X8 MHTs with 235 45 17 front, 245 45 rears, Lots more!

quote Originally posted by Dennis LaGrua: I would forget about the GETRAG with a V8 or high power application. As far as sticks go the GETRAG is flimsy. It has a small input shaft which turns on light needle bearings. It's narrow gears will survive 250 ft lbs of torque but if you race with that tranny and a v8 I guarantte it won't last long. Now get ready for the classic answer sure to be posted next "well I've been using a GETRAG with my V8 and have had no problems" I will simply say to those with blind faith in this gearbox; do you race? If so don't flame, just wait and see for yourself! Used for it's intended application the Getrag is a great tranny. Used with a V8 -IT'S WEAK, VERY WEAK.

------------------

[This message has been edited by California Kid (edited 05-28-2002).]

Getrags work great with V8s in Fieros. Take it from someone who has/drives one. I'm going to list off just some of the stuff I have put my Fiero through.

At least once daily I launch the car as hard and as fast as I can. I usualy run into someone new who wants to go for a ride so I try and leave them with a good impression.

Last summer I racked up 7500 miles which consited of:

1. Letting people drive my Fiero as hard and as fast as they can(at least 10-15 different drivers).

2. Street racing, did quite a bit of this at local hangouts on the weekends. Most nights I raced at least 5 times, a couple nights I raced over 15 times! I have witnesses to this and video to back it up!

3. Visted the dragstrip once last year at the very end of the season.

This summer so far I have:

1. Given rides again to everyone I gave rides to last year. Again they wanted to feel the V8 Fiero launch so I couldn't let them down!

2. I LET MY GIRLFRIEND DRIVE IT! this needs no explaining.

3. Spent a weekend trying to find out the best way to launch my Fiero, at least twenty hard starts.

I now have just over 9,000 on my setup since the swap.

Do I drive my car hard? Yes. How often? At least evryday. Should I go a little easier on it? Maybe, but I didn't build this thing to be a show queen. Have I had any getrag problems? Nope, not a one. I did not rebuild it when I did the swap, its just a stock getrag five speed with over 100,000 miles on it. Am I the only one who has had a great track record with a getrag? NO, I know of at least 10 people personaly that have never had a problem or faliure. I know of NONE that has.

BTW, on the old fiero list Dennis used to try and convince people that the fiero frame couldn't take the torque of a V8. Stating that the cradle couldn't take it, all the while ignoring that there are hundreds of V8 fieros with no reported frame problems.

Jim
87 GT T-TOP V8
87 GT

Dennis is a turbo V6 expert and very knowledgable guy. From his perspective a V8 is just too much. On the other hand, Archie has been telling everyone that all the Fiero transaxles will hold up to a V8. It's only natural he'd take that viewpoint.
While General Motors didn't exactly say which transaxle they think is strongest, they have clearly indicated that they don't trust the Isuzu behind anything but a 4 cylinder. When they had their hands in racing Fieros, they chose the 4 speed over the Isuzu. They didn't offer the V6 with a 5 speed until the Getrag was ready.
The strongest transaxle is the 4 speed with a HD race case and Webster gears. Next would be the Getrag HD race case with Webster gears, then the stock 4 speed (wider gears), the stock Getrag, then the 5 speed Isuzu.
Poor shifting likely destroys more transaxles than too much torque. All Fiero transaxles can benifit from extra case support at the final drive. Torque tends to push gear pairs apart and the axle motion puts twisting pressures on the case, too.
I think that if the adapter plate was extended to surround the right side of the axle opening the life of a transaxle could be greatly extended.
If you plan of shifting wrecklessly, get a pile of Isuzus and change then regularly.

Archie's post wins.. it says it all.

Hey, thanks for providing the name/location of Jims Performance Transmissions in Lansing. After I have my conversion done, now i know where i can take my fiero. Close to me!

quote Originally posted by Dennis LaGrua: I believe that we are talking about transmission strength in this post. Face it, for high power applications all Fiero transmissions are light duty. The TH-125H can be built to take quite a bit more power ( nearly bulletproof) but this involves installing larger bands, additional clutches, a shift kit and a higher stall speed torqueconverter. Jims Performance Transmission (JPT) in the Lansing Michigan area has been building these high strength TH-125H race automatics for years. I have one in my Fiero and it shifts hard and strong. There is no "comfort" slippage at all. In as muchh as my tranny is holding up to the power of my turbo engine I do think that more gears are better. The 4T60 transmission used on many 3800, 3400 and 3100 engined GM cars is pretty tough and offers four speeds. It's a difficult swap as you'll need to change axels but this tranny is quite strong. I would forget about the GETRAG with a V8 or high power application. As far as sticks go the GETRAG is flimsy. It has a small input shaft which turns on light needle bearings. It's narrow gears will survive 250 ft lbs of torque but if you race with that tranny and a v8 I guarantte it won't last long. Now get ready for the classic answer sure to be posted next "well I've been using a GETRAG with my V8 and have had no problems" I will simply say to those with blind faith in this gearbox; do you race? If so don't flame, just wait and see for yourself! Used for it's intended application the Getrag is a great tranny. Used with a V8 -IT'S WEAK, VERY WEAK.

quote Originally posted by peabody: The strongest transaxle is the 4 speed with a HD race case and Webster gears. Next would be the Getrag HD race case with Webster gears, then the stock 4 speed (wider gears), the stock Getrag, then the 5 speed Isuzu.

I'd like to know more about the HD cases and gears. What other information do you have?

Also, recently GM put a Getrag behind a prototype supercharged Grand Am 3.4 Litre V6 putting out 289 ftlbs of torque and gave it to automotive journalists for write ups. I think GM has confidence in the trans' ability to hold that much torque under hard driving.

Sorry, Crypto, I don't have any cute smiley faces with flags for you, just transaxle information. If everything Archie says is gospel, don't bother reading information offered by others. It'll likely confuse you.
Webster made gears for the IMSA Fieros during the 1980s and continues to make gears for race cars, mostly Imports. They do have a supply of gears for both the 4 speed and the Getrag. Those gears cannot be used in stock cases without machine work. Perhaps they will have some leads on HD cases. I'm sure they are expensive. They are straight cut gears and will be louder and engagement a bit stiff.
GM has made several Getrags besides the one found in Fieros. It does sound reasonable that the ones GM put behind the newer, higher horsepower engines would hold up better than a 16 year old 150,000 mile Getrag out of a Fiero.
No comments on an adapter plate that also supports the weak transaxle case?

Does webster have a website?
Do you have contact information?

I searched briefly, but only found these two:
http://www.webster-hoff.com/ http://www.powderedmetalparts.com/

Both of whom make powdered metal gears, which aren't exactly appropriate to this application.

PBS engineering (http://www.pbseng.com/) sells webster gears, but they're listed by part number, not aplication.

[This message has been edited by Will (edited 05-26-2002).]

I can not find any good info the Webster gears also. I do have this info, though I have not had the time to contact them yet. Any one had any experience with them?

Cut & pasted from my e-mail below.

Hey John

Thank you for your inquires. we can do anything. Call me toll free at 877-627-8852 for more personalized service.

Thank you again,
Rusty
TCS Performance
-----Original Message-----
From: John Bailey <jpbaily1@earthlink.net>
To: Info@tcsperformance.com <Info@tcsperformance.com>
Date: Monday, May 13, 2002 3:19 PM
Subject: Fiero transaxle gear

Sir:

Do you carry parts for the Fiero community? I am looking to get more top end for my V 8 install in my 1986 4spd Fiero GT. There is a great demand for these parts for us, but little in supplies. Can you help? Do you do custom work?

Thanks for your time.

------------------
1986 GT 355 Chevy 420hp

So basically what this all boils down to is that the people who like stats say the Getrag tranny won't hold up to the V8.

Yet there are no reports of them failing with a V8 attached.

However, if your going to beat the living hell out of the car with a high horsepower engine you might want to beef it up to be on the safe side?

So where and how do you do that while still keeping it streetable?

------------------
Former SN is FieroGTS- Add 200 posts to post count.

quote Originally posted by JEDI: So where and how do you do that while still keeping it streetable?

You keep the power and torque limited to the 300 to 400 mark. You also don't pull hole shots by side stepping the clutch at high rpm, mid engine cars don't like it due to incredible downforce on the rear tires from weight transfer. High torque V8's don't require a hot shot anyway, they easily take off like a bat of hell just from launching at 1,500 rpm.

If you want to go higher horse/torque, now you're in the experimenters group, or wild hot rodder. Wild Hot Rodders expect parts to break after a while and just replace them with no complaints.

Sound file next to my signature is the way I drive mine most of the time, has lasted 30,000 miles so far with no complaints, and the trans had 90,000 miles on it before the V8 went in.

------------------

[This message has been edited by California Kid (edited 05-28-2002).]

Thanks to all that have made comments to this post.
Some construe that with my comments on transmisson strength that I am trying to convince Fiero owners not to go with a V8 conversion. This is not the case at all.
As I see it the V8 Fiero holds with it many advantages, three of the most obvious are reliability, ease of modification and power potential. I am a big fan of the SBC engine and have seen quite a few nice Fieros with V8.s. It is not my personal choice on power vs cost and weight but,it certainly remains a viable option.
In drag racing you quickly learn that when you change one thing, two more items that you overlooked also need changing. For instance if you replace a small block with big block you will find that the exhaust system is not adequete. Add a roots blower or a turbo to a specially built engine and you will find that the stock ignition system and fuel supply system needs upgrading as well. If you substantially up the power you may need suspension and drivetrain mods to get the power to the ground.
Many years of racing, and working on custom cars and hot rods, has taught some valuable lessons. This is where my belief in modification as a complete system was developed.
The point is, if you want a V8 Fiero that's fine but building it correctly to avoid problems later on may be a good idea.
Compared to other transmisson choices I stated that the Getrag is weak. Fact is that it was designed by GM for V6 power and torque and not for V8 power. Take a Getrag apart and look at the size of the input shaft, the small needle bearings that support it and the shift forks. Examine the width of the gears. They are even narrower than the Muncie. Five speeds in the same place as four required Gm to narrow the gears. Pure physics will tell you that narrow gears are weaker.
When doing a V8 swap or even installing a high power turbo V6 I believe that it makes perfectly good sense to install a transmission which was specifically designed and built for higher power applications.
It is certainly one's right to bolt in any engine that they choose without changing anything else or you could also choose to build your Fiero as a system.
It may be better to think about it three times and build it once than to think about it once and end up building it three times!!!

------------------
87GT 3.4 Turbo Best 0-60 5.2 seconds
http://turbofiero.fierojoe.com/turbo.htm

Give it up Dennis, the Getrag will hold up fine behind a V8. Like anything it will grenade if abused. You can grenade a Fiero tranny with a 4 banger in there if you want.

Having worked on Fiero's for the past 13 years, the Fiero transaxle with the highest failure rate that my shop has seen has been the 4 spd Muncies. I've taken quite a number apart with broken teeth on the input gears, and input shafts that were scored severly on the machined surfaces where the gears ride.

If you want I have boxes full of destroyed 4 spd transaxle internals, your welcome to examine them any time.

I am not saying 4 spds are junk, just that compared to both the Isuzu, and the Getrags, they have a higher failure rate.

I have a Getrag here that has enough use on it that the shift forks are worn out, the gears still run smoothly on the shafts, and the gears them selves are in surprisingly good condition.

If you play with these transaxles as much as you claim, then you know that the internal width of the Getrag case is roughly the same as that of the 4 spds. You also know that like the Isuzu, the 5th gear(s) are located outside of the main internal cavity. Then you also know that the external dimensions of the 5 spds are wider than the 4 spds.

It is not only the width of the gear sets that give them the strength, it is the gear cut. Straight versus Helical. Straighter is stronger, more angle ( helical )is quieter. Ever hear a Getrag sing when pushed hard? Thank that due to the straighter gear cut than that of the 4 spd gear sets.

Your on a loosing battle here, the facts are overwhelming you. 50 people could tell you that their Getrag behind a V8 is working fine, and you would still persist that it is not up to the job at hand.

------------------

quote Originally posted by JEDI: So basically what this all boils down to is that the people who like stats say the Getrag tranny won't hold up to the V8. Yet there are no reports of them failing with a V8 attached. However, if your going to beat the living hell out of the car with a high horsepower engine you might want to beef it up to be on the safe side? So where and how do you do that while still keeping it streetable?

Very succinct - I like it!

quote Originally posted by Dennis LaGrua: Compared to other transmisson choices I stated that the Getrag is weak.

I have seen you bring this up numerous times but have yet to see some documented failures.

Rob D.

------------------

Modified 2.8 (Soon to be a 383 V8 )
2.5" Drop
11" Brakes
17" Revolutions
RCC Coilover Suspension

Try Webster gears Inc at 415-388-1494. I think that's in the Chicago area. They had some final ratios between 3.26 and 4.82
Pontiac's part number for the Race Muncie 4 speed case is #10042330. I don't know if any of this is current. If you do get in touch with the nice folks at Webster Gears, do it only if you are serious. I'd hate to think I've unleashed a bunch of "If I wasn't so broke..." onto a company that could do the Fiero community some good.

quote Originally posted by peabody: Try Webster gears Inc at 415-388-1494. I think that's in the Chicago area. They had some final ratios between 3.26 and 4.82 Pontiac's part number for the Race Muncie 4 speed case is #10042330. I don't know if any of this is current. If you do get in touch with the nice folks at Webster Gears, do it only if you are serious. I'd hate to think I've unleashed a bunch of "If I wasn't so broke..." onto a company that could do the Fiero community some good.

Thanks! I'll give it a shot. Don't worry, I'm good at being discreet about how broke I am.

[This message has been edited by Will (edited 05-29-2002).]

Your on a loosing battle here, the facts are overwhelming you. 50 people could tell you that their Getrag behind a V8 is working fine, and you would still persist that it is not up to the job at hand

It seems that it someone else who is trying to win a battle, certainly not I. I'm just trying to open up discussion on the Fiero drivetrain and particpate in the open exchange of ideas and opinions. Apparently design limits is not a topic that many wish to discuss. Certainly you are are not claiming that the GETRAG can take unlimited power?
You talk about facts. What facts are you providing other than circumstantial evidence?
How are these Getrags used that are working? How many miles were on them? Were they used for Street, street/strip, 1/4 mile drags? Your post does not provide any engineering data or mechanical evidence to back up long term reliability of the Getrag V8 combination.
It doesn't matter to me if someone wishes to bolt a 600 HP engine into a Fiero with a GETRAG but this tranny (as all GM components) does have design limits. Cetainly a highly skilled race car mechanic as you, knows this

------------------
87GT 3.4 Turbo Best 0-60 5.2 seconds
http://turbofiero.fierojoe.com/turbo.htm

"It doesn't matter to me if someone wishes to bolt a 600 HP engine into a Fiero with a GETRAG but this tranny (as all GM components) does have design limits. "

So drop it, if it means nothing to you, just drop it.

------------------

[This message has been edited by jelly2m8 (edited 05-29-2002).]

If we all lived our lives according to design specifications this would be a pretty boring planet.
I'd rather live my life according to real world specifications, not theoretical limits.
To Each His Own!

tstroud

quote Originally posted by Dennis LaGrua: Apparently design limits is not a topic that many wish to discuss. Certainly you are are not claiming that the GETRAG can take unlimited power?

As if there is "any" tranny made that does take umlimited power..? (NOT) Even the best lawyer in the world cant prove his case or argument witout "evidence" and so far you have brought nothing to the table to prove that manual transaxles have failed with V8 swaps. Sure "everything" has design limits, but I would have to say that the dozens and dozens of satisfied V8 owners on the road right now is more than enough proof to show they are good enough to handle the job.