Auto trans in the 88 has died so I wondering if I can use a newer fwd trans, pref just bolt up and go. Anyone know what cars I should be looking at to get a suitable trans. Need to keep costs down so a stright replacement is pretty much all I am looking for.
I have an 87 that was just pulled from a car for an engine swap. 130k miles. $125 and I could meet you somewhere in SC for delivery. Includes axle shafts.
Most are E trans and will not work in Fiero. 3T40 is an update name for TH125c but bell housing pattern does match to Fiero engines I'm told.
Get later year of TH125c... Later year, GM has fixes updates etc build in...
------------------ 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)
The t125 is a good transmission, better ,more reliable than the 4 speed the T125 can be open up and the gears and chain replaced for better gas MPG & lower RPM hiway use before you reinstall if your use is 90 to 95 % around town keep it stock there must have been 5,000,000 of these transmissions built in various forms with mimnimal maintenence one of these transmissions will outlast the owner but ya gotta change the fluid & ajust the TV cable ,,most people drive this transmission untill it fails prematurely because lack of Maintenence do not think dropping in a 4 speed will be easy ,tho now would be the time
it is design for around town use
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08:16 PM
darkhorizon Member
Posts: 12279 From: Flint Michigan Registered: Jan 2006
4t60 seems like a great upgrade to me... the install is fairly simple, but you will have to fiddle with a new passenger side axle (using off the shelf parts at least).
On top of that you will probably have to get the welder out for some simple "fit suggestion" action.
Yes, the 4t60 is an awesome upgrade. I haven't had any issues with the axles though, I just bought a driver and passenger side axle for a 1989 Pontiac 6000 with the 4-speed and light duty brakes.
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10:35 PM
Jul 21st, 2011
2farnorth Member
Posts: 3402 From: Leonard, Tx. USA Registered: Feb 2001
Yes, the 4t60 is an awesome upgrade. I haven't had any issues with the axles though, I just bought a driver and passenger side axle for a 1989 Pontiac 6000 with the 4-speed and light duty brakes.
Did you adapt to the newer VSS on the 4t60? I tried to find the older Fiero compatable one around here and couldn't find a usable one.
Is the transmission used in the 3.1 Grand Am's the same? They were 125's, IIRC. Our 93 had the TH125, but we had the 3.3 so it had a differrent bell housing.
Is the transmission used in the 3.1 Grand Am's the same? They were 125's, IIRC. Our 93 had the TH125, but we had the 3.3 so it had a differrent bell housing.
This is confusing, the 3.1 doesn't have a different bell housing if that's what you meant.
[This message has been edited by mattwa (edited 07-21-2011).]
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06:57 PM
PFF
System Bot
fierofool Member
Posts: 12955 From: Auburn, Georgia USA Registered: Jan 2002
The 3.3 used in the 93 Grand Am was a 90 degree engine. I believe all the 3.1's were 60 degree like the 2.8 so they would probably have the same bell housing. If they used the TH125 in those 3.1 equipped cars, it may be interchangeable and be a newer transmission.
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07:23 PM
Jul 22nd, 2011
hercimer01 Member
Posts: 2308 From: Rockford IL. Registered: Mar 2008
The 4T60E is PCM controlled if you want to dive into the deep end.
I used Alex4mula thread as a reference to do my 4t60 and found out towards the end he gave up on it due to problems with the trans. (It sat for two years after the rebuild before installing it.) I did finish mine but i too had problems with my trans. (bad rebuild) His thread very helpful and detailed. I wouldn't even consider going back to a 3 speed or without a 4 speed. Manual with a turbo definitely.
The 3.3 used in the 93 Grand Am was a 90 degree engine. I believe all the 3.1's were 60 degree like the 2.8 so they would probably have the same bell housing. If they used the TH125 in those 3.1 equipped cars, it may be interchangeable and be a newer transmission.
Both the 90* V6 and 60* V6 had the same bolt pattern, so that's not an issue.
Mounts needed to be made. Also the shifter linkages need to be fabricated by hand, nobody makes a kit to make those changes easy.
Also the VSS sensor, you have to search for a 4T60 that has the right one and nobody has a good way of identifying what is the right one. the 4T440 is the older version of the 4T60 and I believe it has the right sensor on it. But I am not 100% sure.
Mounts needed to be made. Also the shifter linkages need to be fabricated by hand, nobody makes a kit to make those changes easy.
Also the VSS sensor, you have to search for a 4T60 that has the right one and nobody has a good way of identifying what is the right one. the 4T440 is the older version of the 4T60 and I believe it has the right sensor on it. But I am not 100% sure.
You need fabrication skills to do this swap.
No, you do not need to make any mounts, stock fiero rubber mounts and 4t60 brackets work great, all you have to do is drill two new holes in the rear mount. You can buy the shifter bracket, but sure he is able to make his own. Finding the correct one is difficult, it is the older ones that have it (85-88 ish). If you had a picture it would be easy to spot one. If its not the pluse type, it will work. Look for one similar to the 3 speed, even if it uses a speedo cable it will work, just use the 3 speeds sensor.
No, you do not need to make any mounts, stock fiero rubber mounts and 4t60 brackets work great, all you have to do is drill two new holes in the rear mount..
That is considered making a mount by a lot of people.
And I have yet to find anyone that sells the shift linkage brackets, if you have found them post a link here for this guy so he does not have to search for them. It will save a LOT of time making something up.
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05:56 PM
Dennis LaGrua Member
Posts: 15761 From: Hillsborough, NJ U.S.A. Registered: May 2000
Simple way to get better performance from the TH-125H. Add one more clutch disc to the clutch pak. Install a Transgo shift kit. Do not use B&M as they stink. Replace the drum with one of higher strength oir weld weak points. Match a new torque convrter to the type of driving that you will do. For instance for street/strip use a 2500-2700 RPM stall speed converter for mileage use a 2000 -2200 RPM stall speed converter, They are easy to rebuild. If you don't know how ,you can buy a manual or instruction video that will take you through the process. The only tricky part is remembering where all of the check balls in the valve body go but you could always take pictures.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, 3.4" Pulley, N* TB, LS1 MAF, Flotech Exhaust Autolite 104's 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 "
That is considered making a mount by a lot of people.
And I have yet to find anyone that sells the shift linkage brackets, if you have found them post a link here for this guy so he does not have to search for them. It will save a LOT of time making something up.
I made a typo, I meant all you had to do was drill two new holes in the rear mounting location on the cradle itself, but I understand your point.
They are made my West Coast Fiero, and here is the link. It's on this page http://www.westcoastfiero.c...ion_accessories.html It's the "T465E & T465EHD Transmission Shifter Adapter" I pretty sure it will work on the 60 and 60e also, but don't hold me down on that. It serves a dual purpose as it keeps the plastic end of the cable away from the exhaust crossover on the 4.9 and 3800 swaps, but of course that doesn't matter in the OP's case.
And Dennis, yes you can beef up the TH125C, but I would never want to, having that 4th gear, the over-drive, is very much worth the extra time and expense, even more now considering the price of gas.
[This message has been edited by mattwa (edited 07-22-2011).]
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07:53 PM
Dennis LaGrua Member
Posts: 15761 From: Hillsborough, NJ U.S.A. Registered: May 2000
Matt: Yes I wholeheartedly agree that the TH-125H even beefed up is not the ideal solution. What I should have said is that its the easy way to get back on the road without doing any conversion type work. I much prefer the 4 speed autos myself for their better highway mileage and overall drivability. The overdrive forth makes for an especially nice highway ride.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, 3.4" Pulley, N* TB, LS1 MAF, Flotech Exhaust Autolite 104's 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 "
Matt: Yes I wholeheartedly agree that the TH-125H even beefed up is not the ideal solution. What I should have said is that its the easy way to get back on the road without doing any conversion type work. I much prefer the 4 speed autos myself for their better highway mileage and overall drivability. The overdrive forth makes for an especially nice highway ride.
Yes, you are correct Dennis.
ltlfrari, if I remember correctly from your website, your 88 is an Iron Duke car, I forgot about this till just now. Personally, i would not put a 4t60 next to an iron duke, since it takes even more power away from the engine with the bigger pump and increased weight will make the slow combo of the duke/3-speed even worse. Another issue is it would need to frequently downshift to even accelerate at highway speeds, it couldn't handle the 0.70 overdrive for anything other then light cruising.
I made a typo, I meant all you had to do was drill two new holes in the rear mounting location on the cradle itself, but I understand your point.
They are made my West Coast Fiero, and here is the link. It's on this page http://www.westcoastfiero.c...ion_accessories.html It's the "T465E & T465EHD Transmission Shifter Adapter" I pretty sure it will work on the 60 and 60e also, but don't hold me down on that. It serves a dual purpose as it keeps the plastic end of the cable away from the exhaust crossover on the 4.9 and 3800 swaps, but of course that doesn't matter in the OP's case.
$120.00 for 3 pieces of stamped metal. really.. WCF's prices have spiraled out of control $50-$60 I can see. $120 is just obscene.
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09:23 PM
Jul 23rd, 2011
Carcenomy Member
Posts: 1109 From: Invercargill, New Zealand Registered: Jan 2009
I've been looking for an upgrade for the 125C myself for a while, the 4T60 sounds like just the ticket. But are there any other options? 4T40?
Not really, the 4t60 is the easiest on a stock fiero engine because of the direct bolt up to the engine, most others have a different bolt pattern or other fitment/mounting issues that lead to more work then needed. The 4T60 is your best bet.
Not really, the 4t60 is the easiest on a stock fiero engine because of the direct bolt up to the engine, most others have a different bolt pattern or other fitment/mounting issues that lead to more work then needed. The 4T60 is your best bet.
4T440 is an older version of the 4T60. They are practically the same. But the 4t-440 suffers from chain stretch with high mileage and when it goes it shreds the birdcage part of the transmission requiring a major overhaul or just a complete tranny replacement to fix it. the 4T60 fixes some of these problems, BUT it is still prone to chain stretch for high mileage. if you buy a junkyard tranny, get it rebuilt first.
4T440 is an older version of the 4T60. They are practically the same. But the 4t-440 suffers from chain stretch with high mileage and when it goes it shreds the birdcage part of the transmission requiring a major overhaul or just a complete tranny replacement to fix it. the 4T60 fixes some of these problems, BUT it is still prone to chain stretch for high mileage. if you buy a junkyard tranny, get it rebuilt first.
I don't think he was talking about the TH440-T4, because there is a transmission in the 90's and on called the 4T40. It's a smaller/weaker 4T60 with a different bell housing.
Today, GM uses a simple naming scheme for their transmissions, with the "Hydra-Matic" name used on most automatics across all divisions. 3/4/5/6 Number of forward gears L/T L=Longitudinal T=Transverse ## GVWR rating -E "E" for Electronic "HD" for Heavy Duty
First-generation transverse (Front Wheel drive)
1995– 4T40-E/4T45-E — 4-speed light-duty (used in smaller front wheel drive GM vehicles) 1991– 4T60-E/4T65-E/4T65E-HD — 4-speed medium-duty (used in larger front wheel drive GM vehicles) 1993– 4T80-E — 4-speed heavy-duty (used in large front wheel drive GM vehicles, only with Cadillac NorthStar V8.
Edit: Btw, i would never recommend putting a 4T80e in a Fiero, it is ungodly heavy, around 300lbs, and the 4T65e-HD is good enough.
[This message has been edited by mattwa (edited 07-23-2011).]
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04:22 PM
Carcenomy Member
Posts: 1109 From: Invercargill, New Zealand Registered: Jan 2009
Originally posted by mattwa: I don't think he was talking about the TH440-T4, because there is a transmission in the 90's and on called the 4T40. It's a smaller/weaker 4T60 with a different bell housing. http://en.wikipedia.org/wiki/GM_4T40_transmission
Was definitely meaning the 4T40 - allegedly it was used on the Grand Am with the LA1 3400 V6.
I'm guessing being the lighter duty variant that it'll be a relatively cheap transmission too. Good match to a stock 2.8 I'd say - designed for up to 190ft-lb torque, the 2.8 makes 160ft-lb... a little headroom for mods there.
Was definitely meaning the 4T40 - allegedly it was used on the Grand Am with the LA1 3400 V6.
I'm guessing being the lighter duty variant that it'll be a relatively cheap transmission too. Good match to a stock 2.8 I'd say - designed for up to 190ft-lb torque, the 2.8 makes 160ft-lb... a little headroom for mods there.
Right, but it still will not work with a stock 2.8 because it is electronically shifted, and would need a trans controller to shift. The 2.8 ECM can not control a transmission. the stock 3-speed and the 4T60 non-e are hydraulically shifted, so those will with a 2.8.
It also looks like it takes a much smaller torque convertor.
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12:32 AM
Carcenomy Member
Posts: 1109 From: Invercargill, New Zealand Registered: Jan 2009
The t125 is a good transmission, better ,more reliable than the 4 speed the T125 can be open up and the gears and chain replaced for better gas MPG & lower RPM hiway use before you reinstall if your use is 90 to 95 % around town keep it stock there must have been 5,000,000 of these transmissions built in various forms with mimnimal maintenence one of these transmissions will outlast the owner but ya gotta change the fluid & ajust the TV cable ,,most people drive this transmission untill it fails prematurely because lack of Maintenence do not think dropping in a 4 speed will be easy ,tho now would be the time
it is design for around town use
How difficult is it to change the gears in a TH125?
Seems like with a different final drive and creative gearing you could effectively get 4 ratios with the converter lockup function. From what I hear, the TH125 is a more reliable transmission than most, and the two vehicles i've owned with them have shifted great even with high mileage.
I had a 1987 Buick Century with a Duke and TH125c. It had the 2.87 final drive ratio and cruised at 75 mph very well with the lockup converter engaged. Realize you will lose the acceleration advantage of the 3.33 final drive with this setup. I'd opt for the newer 4 speed in a Fiero if I had a vote. Best of both worlds.
I had a 1987 Buick Century with a Duke and TH125c. It had the 2.87 final drive ratio and cruised at 75 mph very well with the lockup converter engaged. Realize you will lose the acceleration advantage of the 3.33 final drive with this setup. I'd opt for the newer 4 speed in a Fiero if I had a vote. Best of both worlds.
I have a 4.9/4T60e in my Fiero with a 2.73 final drive ratio and I'm doing 1700@70MPH.
