4L60E Barely Moves
Thread Starter
Staging Lane
Joined: Feb 2023
Posts: 65
Likes: 15
4L60E Barely Moves Hi Everyone,
I just bought a 94 Trans Am on Sunday. I'm totally new to F bodies. The LT1 seems to run great but the (auto) transmission isn't working. If I put it in gear and rev up to 3000 rpm or so the car will start to creep slowly, works about the same in any gear, forward or reverse. I checked the fluid level with engine running and it was over full. I have no history on the vehicle, I bought it from a guy who got it in a trade and doesn't know anything about it either. He may have dumped in the extra fluid in an attempt to make it work, I'm not sure.
I'll have access to a lift next week and am planning to drop the pan and change the filter and obviously the fluid.
I'm no transmission expert, what should I look for when the pan is off?
Thank you in advance!
I just bought a 94 Trans Am on Sunday. I'm totally new to F bodies. The LT1 seems to run great but the (auto) transmission isn't working. If I put it in gear and rev up to 3000 rpm or so the car will start to creep slowly, works about the same in any gear, forward or reverse. I checked the fluid level with engine running and it was over full. I have no history on the vehicle, I bought it from a guy who got it in a trade and doesn't know anything about it either. He may have dumped in the extra fluid in an attempt to make it work, I'm not sure.
I'll have access to a lift next week and am planning to drop the pan and change the filter and obviously the fluid.
I'm no transmission expert, what should I look for when the pan is off?
Thank you in advance!
TECH Enthusiast
Joined: Jan 2019
Posts: 677
Likes: 490
From: Roxana, IL
Hi Everyone,
I just bought a 94 Trans Am on Sunday. I'm totally new to F bodies. The LT1 seems to run great but the (auto) transmission isn't working. If I put it in gear and rev up to 3000 rpm or so the car will start to creep slowly, works about the same in any gear, forward or reverse. I checked the fluid level with engine running and it was over full. I have no history on the vehicle, I bought it from a guy who got it in a trade and doesn't know anything about it either. He may have dumped in the extra fluid in an attempt to make it work, I'm not sure.
I'll have access to a lift next week and am planning to drop the pan and change the filter and obviously the fluid.
I'm no transmission expert, what should I look for when the pan is off?
Thank you in advance!
I just bought a 94 Trans Am on Sunday. I'm totally new to F bodies. The LT1 seems to run great but the (auto) transmission isn't working. If I put it in gear and rev up to 3000 rpm or so the car will start to creep slowly, works about the same in any gear, forward or reverse. I checked the fluid level with engine running and it was over full. I have no history on the vehicle, I bought it from a guy who got it in a trade and doesn't know anything about it either. He may have dumped in the extra fluid in an attempt to make it work, I'm not sure.
I'll have access to a lift next week and am planning to drop the pan and change the filter and obviously the fluid.
I'm no transmission expert, what should I look for when the pan is off?
Thank you in advance!
First is the torque converter being shot and it can no longer force the fluid to twist the turbine shaft.
Second the pup is shot and it can no longer pump the fluid to the converter or clutch's to move the car.
That's just me and a 2wd transmission of that year only takes about 30 minutes to get it out and to a bench.
Thread Starter
Staging Lane
Joined: Feb 2023
Posts: 65
Likes: 15
Thanks. So how would I determine the condition of the pump and torque converter to see which one(s) is shot?
And the fresh fluid and filter was going to be out of a naive hope that the filter was simply blocked.
And the fresh fluid and filter was going to be out of a naive hope that the filter was simply blocked.
TECH Enthusiast
Joined: Jan 2019
Posts: 677
Likes: 490
From: Roxana, IL
Once the transmission is out it can be torn down and evaluated for damages. Having drained it helps to keep from making more of a mess from pulling a completely filled unit.
Thread Starter
Staging Lane
Joined: Feb 2023
Posts: 65
Likes: 15
I've read that the 1994 4L60E is not interchangeable with later ones because it doesn't use PWM to control the lockup. I've also read the torque converter clutch itself is different, something about carbon fiber vs paper. Does this mean a replacement torque converter must be specific to the early 4L60E or will the later style torque converters (pre LS) work with the early transmission?
Edit: disregard, I found my answer here: https://ls1tech.com/forums/automatic...-material.html
Edit: disregard, I found my answer here: https://ls1tech.com/forums/automatic...-material.html
Last edited by Chris in Idaho; Apr 19, 2023 at 08:56 AM.
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LS1Tech Sponsor
Joined: Mar 2023
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From: BERWICK PA
Personally based on your description I would not even pull the pan unless to drain fluid for removal. I would just remove rebuild or replace trans and converter. |
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Frank formerly of Performabuilt, Now just me, What can I build for you today? Call or message me. Click sig pic for my facebook
Frank formerly of Performabuilt, Now just me, What can I build for you today? Call or message me. Click sig pic for my facebook
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Joined: Aug 2010
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From: Ann Arbor, MI
Yeah, replacing the fluid would be a total waste of time and money. You obviously have plenty of fluid.
Follow MaroonMonster's suggestion for a quick test.
If you have access to it, a more accurate test is to connect a pressure gauge to the trans. It should give you 50psi+ in Park and 100psi+ in Reverse. Less and your pump is likely shot.
Yeah, the 1994 4L60e is an odd-ball year. A wide range of converters is available.
Follow MaroonMonster's suggestion for a quick test.
If you have access to it, a more accurate test is to connect a pressure gauge to the trans. It should give you 50psi+ in Park and 100psi+ in Reverse. Less and your pump is likely shot.
Yeah, the 1994 4L60e is an odd-ball year. A wide range of converters is available.
LS1Tech Sponsor
Joined: Mar 2023
Posts: 1,821
Likes: 1,159
From: BERWICK PA
I've read that the 1994 4L60E is not interchangeable with later ones because it doesn't use PWM to control the lockup. I've also read the torque converter clutch itself is different, something about carbon fiber vs paper. Does this mean a replacement torque converter must be specific to the early 4L60E or will the later style torque converters (pre LS) work with the early transmission?
Edit: disregard, I found my answer here: https://ls1tech.com/forums/automatic...-material.html
Edit: disregard, I found my answer here: https://ls1tech.com/forums/automatic...-material.html
All the later model converters will work only the early ones would be an issue with the later trans, I would say it would be hard to find a converter with the early clutch lining anymore even if you tried.
Note also if you have CATSTUNER for the OBD1 you can just turn off the code for the 3-2 electrical and it will work fine this is how its set up in my own car as I used a late harness and solenoids in the build 1995 impala ss
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Frank formerly of Performabuilt, Now just me, What can I build for you today? Call or message me. Click sig pic for my facebook
Frank formerly of Performabuilt, Now just me, What can I build for you today? Call or message me. Click sig pic for my facebook
Thread Starter
Staging Lane
Joined: Feb 2023
Posts: 65
Likes: 15
Thanks everyone, I'm impressed by the knowledge on this site and glad to have it as a resource. So no chance the problem could be just a clogged filter? I purchased the car knowing the seller tried to drive it and transmission didn't work, which made it really cheap. My goal for the car is super low buck bracket racing. I have a th400 that I was planning to swap in. However, when we rolled it off the trailer and I tried it and got it to roll forward and backwards, I thought maybe that means there aren't any hard parts broken. It seemed like it was trying to work. I thought maybe the 29 year old filter is just clogged up (see, I know nothing about transmissions) and maybe I could start driving the thing now without having to swap the tranny. But if it probably needs a pump and torque converter, or if I need to pay someone's shop rate to fix it for me, then I should just proceed with "plan A". Instead of throwing any money at the 4L60E trying to figure out whats wrong, I'll just put that toward the crossmember and driveshaft work I'll need for the th400. Thanks
TECH Junkie
Joined: May 2012
Posts: 3,048
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From: Poplarville, MS
Thanks everyone, I'm impressed by the knowledge on this site and glad to have it as a resource. So no chance the problem could be just a clogged filter? I purchased the car knowing the seller tried to drive it and transmission didn't work, which made it really cheap. My goal for the car is super low buck bracket racing. I have a th400 that I was planning to swap in. However, when we rolled it off the trailer and I tried it and got it to roll forward and backwards, I thought maybe that means there aren't any hard parts broken. It seemed like it was trying to work. I thought maybe the 29 year old filter is just clogged up (see, I know nothing about transmissions) and maybe I could start driving the thing now without having to swap the tranny. But if it probably needs a pump and torque converter, or if I need to pay someone's shop rate to fix it for me, then I should just proceed with "plan A". Instead of throwing any money at the 4L60E trying to figure out whats wrong, I'll just put that toward the crossmember and driveshaft work I'll need for the th400. Thanks
