Rebuilt 4L60E,What Went Wrong?
02-15-2012, 02:48 PM
#1
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Rebuilt 4L60E,What Went Wrong? This past weekend my dad had time to pull my trans out and rebuild it,upon tearing apart the trans we found out that some of the clutches were badly burnt(overdrive clutches I believe).I was experiencing some slippage which is why I was getting it rebuilt in the first place.My dad has been a mechanic for over 15 years,he's rebuilt 4l60e's before so I trust him with his work,but it is possible he could have misassembled something.
After getting the trans is back in,we added fluid then went for a test drive and all gears seem to be working properly and shifting fine,we add more fluid so that the fluid level is correct,test drive again and everything is all good.On my way home I drive a few miles or so then I decided to get on it a little bit,I was going between 30-40 mph,I floor it,car downshifts but soon after hits the rev limiter.I come to a stop,try to take off in OD but seems like its in neutral,try to take off in D but acts like its in neutral also.I do have 1st,2nd,and Reverse.I had to drive about 10 miles home just in second gear so idk if I damaged other stuff along the way.My car is at a local trans shop for diagnosis and I'm waiting for a call back to hear what they found but my trans guy says it sounds like the input sprag could have broke.I also didn't add a new converter or replace the solenoids either,the car is almost stock with 104k miles so I'm sure those things need to be replaced.
And man do I miss my car,its been sitting up since June of 2011,I was out of a job for a few months so I didn't have the money to fix it,and now that I'm in the process of getting it fixed the waiting game is killing me haha.
After getting the trans is back in,we added fluid then went for a test drive and all gears seem to be working properly and shifting fine,we add more fluid so that the fluid level is correct,test drive again and everything is all good.On my way home I drive a few miles or so then I decided to get on it a little bit,I was going between 30-40 mph,I floor it,car downshifts but soon after hits the rev limiter.I come to a stop,try to take off in OD but seems like its in neutral,try to take off in D but acts like its in neutral also.I do have 1st,2nd,and Reverse.I had to drive about 10 miles home just in second gear so idk if I damaged other stuff along the way.My car is at a local trans shop for diagnosis and I'm waiting for a call back to hear what they found but my trans guy says it sounds like the input sprag could have broke.I also didn't add a new converter or replace the solenoids either,the car is almost stock with 104k miles so I'm sure those things need to be replaced.
And man do I miss my car,its been sitting up since June of 2011,I was out of a job for a few months so I didn't have the money to fix it,and now that I'm in the process of getting it fixed the waiting game is killing me haha.
02-15-2012, 10:27 PM
#2
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First, I think you meant overrun clutches; not "overdrive clutches".
The overrun clutches are small (only 2 frictions) and are primarily designed to provide engine braking when going downhill (e.g. in the mountains) when you have downshifted the trans into [1], [2] or [3]. The forward (overrun) sprag is designed to transmit engine power to the rest of the trans and drive train. However, if the sprag is shot/slipping, the overrun clutches can transmit power in [1], [2] or [3] (but not in [D]rive), but would quickly wear out.
I'm no trans expert, but in theory if the overrun clutches are badly burnt, that would be a good indicator that the forward sprag is shot, precisely as the trans shop suspects. Sorry, sounds like you need a partial rebuild.
The overrun clutches are small (only 2 frictions) and are primarily designed to provide engine braking when going downhill (e.g. in the mountains) when you have downshifted the trans into [1], [2] or [3]. The forward (overrun) sprag is designed to transmit engine power to the rest of the trans and drive train. However, if the sprag is shot/slipping, the overrun clutches can transmit power in [1], [2] or [3] (but not in [D]rive), but would quickly wear out.
I'm no trans expert, but in theory if the overrun clutches are badly burnt, that would be a good indicator that the forward sprag is shot, precisely as the trans shop suspects. Sorry, sounds like you need a partial rebuild.
02-16-2012, 11:38 AM
#3
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First, I think you meant overrun clutches; not "overdrive clutches".
The overrun clutches are small (only 2 frictions) and are primarily designed to provide engine braking when going downhill (e.g. in the mountains) when you have downshifted the trans into [1], [2] or [3]. The forward (overrun) sprag is designed to transmit engine power to the rest of the trans and drive train. However, if the sprag is shot/slipping, the overrun clutches can transmit power in [1], [2] or [3] (but not in [D]rive), but would quickly wear out.
I'm no trans expert, but in theory if the overrun clutches are badly burnt, that would be a good indicator that the forward sprag is shot, precisely as the trans shop suspects. Sorry, sounds like you need a partial rebuild.
The overrun clutches are small (only 2 frictions) and are primarily designed to provide engine braking when going downhill (e.g. in the mountains) when you have downshifted the trans into [1], [2] or [3]. The forward (overrun) sprag is designed to transmit engine power to the rest of the trans and drive train. However, if the sprag is shot/slipping, the overrun clutches can transmit power in [1], [2] or [3] (but not in [D]rive), but would quickly wear out.
I'm no trans expert, but in theory if the overrun clutches are badly burnt, that would be a good indicator that the forward sprag is shot, precisely as the trans shop suspects. Sorry, sounds like you need a partial rebuild.
