4l80e issues?
4l80e issues? I 4l80e swapped my AWD Silverado SS and while it was down I decided to go through my engine. I installed ported/unshrouded 706 heads, GMPP oil pump, Morel lifters, CHE rocker bushings, TSP 228/232 .600 cam/springs/pushrods, Aeromotive 340 fuel pump, Tick hotwire kit, TBSS intake and 42lb FIC injectors. I sent my 278mm Circle D 3200 converter back to have it made to fit the 4l80e (didn't know that was possible until I contacted them).
Everything installed and back together I took the truck to have it tuned and on the first pull my tuner said it looked like my torque converter was trying to lock up in the middle of 1st gear. The RPMs would stall out at 32-3600 but the MPH would continue to climb and then it would pick back up after a 5-6mph climb. The log did not show converter lockup and I verified fluid levels at hot idle. I downloaded Bluecat to help with the shifts (AMAZING!) and tried to work some kinks out on my own (I own HPTuners). I got the transmission shifting perfectly again and everything was going well for a couple of weeks except I had a nasty idle surge when up to operating temp in gear or at a very low roll and the truck would die as soon as I put it in reverse when hot...and only when hot. I thought it was an issue with the tune but it kept getting worse to the point that the truck would surge in Park and die once up to temp. That allowed me to log scans with easy to see information and I noticed the idle torque output was spiking right before the engine would lug and surge. Also when rolling to a stop and taking off the truck felt like the converter was locked up until I hit the throttle then the RPMs would go up and the truck would take off as it should.
Finally I drove the truck to work one day to do some logging and after pulling into my driveway I discovered that I lost reverse. I checked the fluid level and it was extremely high. I had been keeping a very close eye on the fluid level and it was perfect until this happened. The transmission hasn't had any overheating issues this whole time. The truck will engage and push back for 5-10ft then torque output goes to 0 and the truck stops moving. 3rd and 4th also slip but if I manually pull it into 2nd or 1st it will pull right back into the driveway perfectly. I did some reading and tried unplugging the electrical harness from the transmission as suggested and still have the same issue. Also after sitting overnight the fluid levels are back to normal. I let the engine warm up at idle and the fluid reads at the bottom of the HOT line with the transmission at around 115 degrees. Normally with the transmission at 135-150 (as hot as it typically gets driving) it was right at the top of the hot line so I feel it's still spot on. The fluid doesn't smell burned and it's not foamy. HELP!
Everything installed and back together I took the truck to have it tuned and on the first pull my tuner said it looked like my torque converter was trying to lock up in the middle of 1st gear. The RPMs would stall out at 32-3600 but the MPH would continue to climb and then it would pick back up after a 5-6mph climb. The log did not show converter lockup and I verified fluid levels at hot idle. I downloaded Bluecat to help with the shifts (AMAZING!) and tried to work some kinks out on my own (I own HPTuners). I got the transmission shifting perfectly again and everything was going well for a couple of weeks except I had a nasty idle surge when up to operating temp in gear or at a very low roll and the truck would die as soon as I put it in reverse when hot...and only when hot. I thought it was an issue with the tune but it kept getting worse to the point that the truck would surge in Park and die once up to temp. That allowed me to log scans with easy to see information and I noticed the idle torque output was spiking right before the engine would lug and surge. Also when rolling to a stop and taking off the truck felt like the converter was locked up until I hit the throttle then the RPMs would go up and the truck would take off as it should.
Finally I drove the truck to work one day to do some logging and after pulling into my driveway I discovered that I lost reverse. I checked the fluid level and it was extremely high. I had been keeping a very close eye on the fluid level and it was perfect until this happened. The transmission hasn't had any overheating issues this whole time. The truck will engage and push back for 5-10ft then torque output goes to 0 and the truck stops moving. 3rd and 4th also slip but if I manually pull it into 2nd or 1st it will pull right back into the driveway perfectly. I did some reading and tried unplugging the electrical harness from the transmission as suggested and still have the same issue. Also after sitting overnight the fluid levels are back to normal. I let the engine warm up at idle and the fluid reads at the bottom of the HOT line with the transmission at around 115 degrees. Normally with the transmission at 135-150 (as hot as it typically gets driving) it was right at the top of the hot line so I feel it's still spot on. The fluid doesn't smell burned and it's not foamy. HELP!
I guess nobody has had anything like this happen? I'm leaning toward the converter having been faulty from the start and finally putting enough material into the transmission to clog the filter.
Ive heard of problems like that with multi-disc lock up converters. Never had an issue myself. maybe have a look at the converter limit valve in the pump. the fluid path for the TCC apply and release oil relies on a lot of things going right.
From what I've been reading I'm leaning toward a worn bushing/seal around the main shaft leaking fluid into the apply side of the converter. Would explain why reverse instantly killed the engine...it has the most line pressure. Hopefully it didn't toast the converter or anything else in the transmission.
