Strange Problem - Calling all experts
07-06-2006, 10:16 PM
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Strange Problem - Calling all experts I have a strange problem with my transmission. During highway cruise when the throttle is released and the vehicle is decelerating at 60-75 mph the torque converter clutch engages and disengages very quickly until the vehicle is below 60mph. This would occur 3-4 times in succession until the vehicle is below that speed. This occurs with the stock transmission tune, I have a 4l80 and 2900stall converter. Attached is a plot of the timing when this occurs - also strange. Please help!
07-06-2006, 10:36 PM
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Hi,
I think my 99 SS has the same problem. I dont know what is exactly happening in terms of the torque converter or gears....ect... The same thing happens, around 60ish MPH when I let off the throttle there is a quick jerk or it feels like the car quickly downshifed and quickly upshifted again. I think you described it the best in terms of the clutches engaging and disengaging. I dont know, could this be the converter locking and unlocking.
My 99SS has a 3500 Yank SS converter with prob. less than 12,000 miles on it and 40,000 miles on the tranny.
Any one else ever had this problem.
I think my 99 SS has the same problem. I dont know what is exactly happening in terms of the torque converter or gears....ect... The same thing happens, around 60ish MPH when I let off the throttle there is a quick jerk or it feels like the car quickly downshifed and quickly upshifted again. I think you described it the best in terms of the clutches engaging and disengaging. I dont know, could this be the converter locking and unlocking.
My 99SS has a 3500 Yank SS converter with prob. less than 12,000 miles on it and 40,000 miles on the tranny.
Any one else ever had this problem.
07-06-2006, 10:50 PM
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This is definitely the TCC disengaging and engaging. The first thing I checked was the transmission TCC but ruled it out because it was the stock tune for a 4l80.
07-08-2006, 06:39 PM
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hey Jamesbond2509,
Does it do this only between 60-75 mph range. I noticed mine will start anywhere around 50mph and beyond. The higher the speed, more noticable the disengaging and engaging is. I was at the track today and talked to a lot of ls1 guys and they weren't sure what could be causing it.
For now, I have learned to drive it with the problem. I keep my distance form other cars on the highway because the disengaging and engaging problems only happens when you come fully off the throttle. So I try to stay partially on the throttle as much as I can. This way I can avoid the problem most of the times.
If you find anything out please keep me posted.
Does it do this only between 60-75 mph range. I noticed mine will start anywhere around 50mph and beyond. The higher the speed, more noticable the disengaging and engaging is. I was at the track today and talked to a lot of ls1 guys and they weren't sure what could be causing it.
For now, I have learned to drive it with the problem. I keep my distance form other cars on the highway because the disengaging and engaging problems only happens when you come fully off the throttle. So I try to stay partially on the throttle as much as I can. This way I can avoid the problem most of the times.
If you find anything out please keep me posted.