4L80E problems. Again.
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11 Second Truck Club
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From: Missouri
4L80E problems. Again. I just built and installed a 4L80E for my truck to replace one that I trashed a few weeks ago. I got it running 6 days ago and have already put right at 1,000 miles on it without any problems. Until today....
I drove the truck to the dyno today and made some pulls without issue. When I was leaving I decided to show out and smoke the tires. I stomped it from a dead stop and the tires went up in smoke instantly then it shifted to 2nd gear. It continued roasting them in 2nd until WHAM it neutraled and the motor bounced off the limiter. I coasted to a stop, turned it off and looked under the hood and under the vehicle. When I started it back up I tried reverse and it would pull but was slipping very bad. I placed it in D4 and it slipped very bad, would barely move. When I pulled it down in D3 it took off normally. I got on the highway and it went 1-2 and 2-3 just fine. I got up to about 70 mph and moved the selector to D4 and it went into OD and locked. I drove it home then stopped and tried taking off from a dead stop in D4 and reverse and same thing-it slips really bad but it works fine if I start in D3. What the heck did I hurt??
I drove the truck to the dyno today and made some pulls without issue. When I was leaving I decided to show out and smoke the tires. I stomped it from a dead stop and the tires went up in smoke instantly then it shifted to 2nd gear. It continued roasting them in 2nd until WHAM it neutraled and the motor bounced off the limiter. I coasted to a stop, turned it off and looked under the hood and under the vehicle. When I started it back up I tried reverse and it would pull but was slipping very bad. I placed it in D4 and it slipped very bad, would barely move. When I pulled it down in D3 it took off normally. I got on the highway and it went 1-2 and 2-3 just fine. I got up to about 70 mph and moved the selector to D4 and it went into OD and locked. I drove it home then stopped and tried taking off from a dead stop in D4 and reverse and same thing-it slips really bad but it works fine if I start in D3. What the heck did I hurt??
I just built and installed a 4L80E for my truck to replace one that I trashed a few weeks ago. I got it running 6 days ago and have already put right at 1,000 miles on it without any problems. Until today....
I drove the truck to the dyno today and made some pulls without issue. When I was leaving I decided to show out and smoke the tires. I stomped it from a dead stop and the tires went up in smoke instantly then it shifted to 2nd gear. It continued roasting them in 2nd until WHAM it neutraled and the motor bounced off the limiter. I coasted to a stop, turned it off and looked under the hood and under the vehicle. When I started it back up I tried reverse and it would pull but was slipping very bad. I placed it in D4 and it slipped very bad, would barely move. When I pulled it down in D3 it took off normally. I got on the highway and it went 1-2 and 2-3 just fine. I got up to about 70 mph and moved the selector to D4 and it went into OD and locked. I drove it home then stopped and tried taking off from a dead stop in D4 and reverse and same thing-it slips really bad but it works fine if I start in D3. What the heck did I hurt??
I drove the truck to the dyno today and made some pulls without issue. When I was leaving I decided to show out and smoke the tires. I stomped it from a dead stop and the tires went up in smoke instantly then it shifted to 2nd gear. It continued roasting them in 2nd until WHAM it neutraled and the motor bounced off the limiter. I coasted to a stop, turned it off and looked under the hood and under the vehicle. When I started it back up I tried reverse and it would pull but was slipping very bad. I placed it in D4 and it slipped very bad, would barely move. When I pulled it down in D3 it took off normally. I got on the highway and it went 1-2 and 2-3 just fine. I got up to about 70 mph and moved the selector to D4 and it went into OD and locked. I drove it home then stopped and tried taking off from a dead stop in D4 and reverse and same thing-it slips really bad but it works fine if I start in D3. What the heck did I hurt??
Thread Starter
11 Second Truck Club
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From: Missouri
I have been running thru my mind how this tranny works and I thought about the roller clutch. How about the direct clutches? If there was a problem in that pack would it cause slippage in reverse and forward when in D4?
In reverse, the overruns are NOT on, so if the overdrive roller clutch is fragged, it will slip.
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I knew the overrun clutches are appled in D3 but I dont understand how the trans works well enough to know which packs, sprags etc assist or help each other. Your explanation makes sense, I was thinking along the same lines cept I thought maybe the directs were smoked and the overruns were what was pulling the whole truck when in D3.
I guess I will work on it a while after work this eve, then pull it apart tomorrow after work.
I used the overdrive roller clutch and drum etc from my '01 trans (the one with the blue cage inserts) because I read where that was an upgrade from the older units. The rest of my internals are '97 model.
I guess I will work on it a while after work this eve, then pull it apart tomorrow after work.
I used the overdrive roller clutch and drum etc from my '01 trans (the one with the blue cage inserts) because I read where that was an upgrade from the older units. The rest of my internals are '97 model.
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Ok I took it out last night and pulled it far enough apart to get to the overdrive sprag and sure enough it is shelled! The roller clutch assembly is destroyed which I was pretty sure of going into it and especially when I saw a little tiny piece of blue plastic in the pan.
I noticed the snap ring for the overrun clutch spring retainer was pushed all the way up to the planetary and kinda ground into the planetary hub. The spring retainer is tore up and the springs were all out of place. The question is, what happened to cause this and how can I make sure it don't happen again? Did the snap ring let loose and cause the piston to over extend thus setting the carnage in motion or did the overrun clutch explode and knock the snap ring out of its groove?
I am only making 420 ft lbs of torque right now, I need this thing to hold up if I am ever going to turn the power up.
I noticed the snap ring for the overrun clutch spring retainer was pushed all the way up to the planetary and kinda ground into the planetary hub. The spring retainer is tore up and the springs were all out of place. The question is, what happened to cause this and how can I make sure it don't happen again? Did the snap ring let loose and cause the piston to over extend thus setting the carnage in motion or did the overrun clutch explode and knock the snap ring out of its groove?
I am only making 420 ft lbs of torque right now, I need this thing to hold up if I am ever going to turn the power up.
Not sure on the snap ring, but next time when doing burnouts, start the burnout in 2nd and immediately shift to 3rd (my STOCK 5.3 can do it in front of a 4L80E and 9 inch with 3.0 gears, so don't tell me its a hp problem 
). If the tires grab (while shifter is in OD, or the trans is still in 2nd) it can blow up the intermediate sprag (if trans is still in 2nd gear) or the overdrive roller clutches (if the shifter is in OD position). Sprags/roller clutches REALLY hate being loaded hard.
). If the tires grab (while shifter is in OD, or the trans is still in 2nd) it can blow up the intermediate sprag (if trans is still in 2nd gear) or the overdrive roller clutches (if the shifter is in OD position). Sprags/roller clutches REALLY hate being loaded hard. Trending Topics
Thread Starter
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From: Missouri
I pulled it the rest of the way apart after work today and checked the clutch packs and cleaned everything up. I started stacking stuff back in and before I knew it, I had it assembled. I put the '97 overdrive roller clutch back in it.
I decided to bolt it to the motor and I got the crossmember under it but that was it-way too tired to go on. I am off tomorrow so if all goes well I will be driving it around in the morning.
I decided to bolt it to the motor and I got the crossmember under it but that was it-way too tired to go on. I am off tomorrow so if all goes well I will be driving it around in the morning.
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11 Second Truck Club
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Joined: Jan 2002
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From: Missouri
I got it running, seems fine. Dang what a pain in the ***. You cant break a 4L80, yeah right lol. Anybody have an anvil they want broke? Just send it to me and I will take care of it in short order 
Hopefully I am done making help requests for a while. If nothing else its been a learning experience and maybe next time I will know enough to help someone else.
Hopefully I am done making help requests for a while. If nothing else its been a learning experience and maybe next time I will know enough to help someone else.
