ive got a 00 qc 4.7l 4x4 and when im maintaining speed either 35 or 60 doesnt matter, the tach bounces about 500 rpma t 35 mph and about 2-300 rpms at 60mph. now at lower speeds i actually feel the transmission shifting or the torque conv is unlocking, either one. it drives great excellerating or slowing down just when cruising at a constant speed. its got 140k miles on it, any advice would be great thanks

joe

 

I have the identical problem. It does go away under load (like towing). I just scanned the "tranny computer" and it has no faults, but I am guessing a kick-down solenoid or the torque converter.

Anyone else?

 

Does it occur all the time or just when running the air conditioning or defrost? Could be the compressor cycling.

 

I had that problem with a 99 gasser had the tranny flushed and added a tranny additive and the problem went away don't know if the filter was plugged or what but it made a big difference

 

It does it with ac on or off, it just started today and wasnt using ac at all. its definately trying or partly shifting i can feel the transmission kinking down when the rpms go up. its always done it at idle with the ac on like sitting at a stop light,but have lived with it. should i have the tranny flushed? we'll see i guess

joe

 

Take a look at your TPS . I had the same problems and just changed the TPS and now its gone.

 

Is there a way to bench test a TPS?

 

you can test the TPS with a digital volt meter. you should have around 1 volt at idle (throttle plates closed) and 4 volts at WOT. Check it with the KOEO (key on eng off). More importantly slowly press the pedal down and slowly release. you should see an even increase and decrease in voltage. WATCH for any glitches/drop outs. for instance if your pushing down on the pedal and it goes from 2.0volts then drops to 1.8 and then jumps to 2.3 volts-that is a dead spot or glitch in the sensor.
I'll be honest with you. With the amount of miles on the transmission, I would not flush it or change the fluid for that matter. If you want to put an additive in use LUBE GUARD only!!! Most others have seal swellers (petroleum distillates) what I call Band aid in abottle. When you change the fluid you are disposing of all the clutch/friction material in the fluid that is holding your trans together. get rid of it and its slip city!!! Most likely what you are experiencing is an issue with the Torque converter clutch. Good luck!!!-Jeff

 

While we are on the topic of trannies, I had mine rebuilt water got in and now it seems okay. There is a shift kit so it's a bit firmer you can feel them. But Sometimes when I have the pedal to the floor It will accelerate to second gear and halfway through it will kick down back to first all of a sudden of course I let of the pedal immediately but what would cause this, having the TV cable to taught? Im not sure becuase If this happens to often it should be fixed.

 

what brand of shift kit? I'll double check the procedure for adjusting your cable if you'll post the year make model and eng size-also is it 4wd?