Converter noise/vibration. Lockup early/unlocking late
03-14-2007, 09:43 AM
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Converter noise/vibration. Lockup early/unlocking late I have a yank truck thruster 3000 in my 99 silverado. Anyone else had a similar problem or an ideas on what to try?
I have recently started having some issues which I thought were in the transmission, but have since narrowed it to the converter. I just installed a rebuilt transmission, completely different core, lock up solenoid, etc. Not the same tranny that came out of my truck. I have the same problem as before. The converter is locking up extremely early (around 5 mph in first gear) and not unlocking until I come almost to a stop. It will not unlock when I hit the brakes as it should. Brake switch seems to be fine, checked it yesterday. TPS seems to be fine as well, works very smoothly both up increasing and decreasing throttle position. I tried to manually disable the TC with the VCM override in HPtuners, but it still seemed to lock up. I also maxed out the lockup speed in every gear and it still seems to be partially locking. I then took my TCC PWM % and set the max and min both to zero to try to keep it from locking up. This seemed to keep it from locking up but I still get a vibration and a whine that seem to be coming from the converter as I am going down the road. I may go ahead and put and put a switch in line for an interrupt to the TCC lockup solenoid just to make sure it is not receiving a signal to lockup.
I have recently started having some issues which I thought were in the transmission, but have since narrowed it to the converter. I just installed a rebuilt transmission, completely different core, lock up solenoid, etc. Not the same tranny that came out of my truck. I have the same problem as before. The converter is locking up extremely early (around 5 mph in first gear) and not unlocking until I come almost to a stop. It will not unlock when I hit the brakes as it should. Brake switch seems to be fine, checked it yesterday. TPS seems to be fine as well, works very smoothly both up increasing and decreasing throttle position. I tried to manually disable the TC with the VCM override in HPtuners, but it still seemed to lock up. I also maxed out the lockup speed in every gear and it still seems to be partially locking. I then took my TCC PWM % and set the max and min both to zero to try to keep it from locking up. This seemed to keep it from locking up but I still get a vibration and a whine that seem to be coming from the converter as I am going down the road. I may go ahead and put and put a switch in line for an interrupt to the TCC lockup solenoid just to make sure it is not receiving a signal to lockup.
03-19-2007, 10:37 AM
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More diagnosis Done some more diagnosing on my converter problem. I piggybacked into the brake switch line with a volt meter and made sure the input to the pcm is functioning properly, which it is. Then I piggybacked the voltmeter into the output from the pcm to the TCC lockup solenoid to make sure it was functioning properly and matched this up with what HPtuners scantool was telling my the converter was doing. Everything matched up fine and the pcm output the the converter seemed to be functioning properly. When the truck shifts into second or third at part throttle it has a shudder right after the shift. I can also feel a slight driveline vibration when cruising. I think there is something wrong with the clutch surface in the converter, but possible a bearing going down or something wrong with a fin. Dave at Yank has been great to deal with on the problem. I have called him several times and I am going to send the converter back to him for inspection. I'll let everyone know how it all turns out.
