AW4 TC Problem

I have an 89 Comanche and the tranny is giving me some problems since i put in my 4.7l. As soon as it shifts into overdrive, the torque converter locks up and the tranny shudders. If I press the brakes lightly, the TC unlocks and the shudder goes away. It shudders more at lower speeds and seems to smooth out a little over 60mph or so.
I recently tried putting in a different TPS and AW4 computer. I have searched the forum but did not find a similar problem or solution.
Thanks

Pat
89 MJ
4.7 L Stroker

Well, if it starts to shudder as soon as the TCC locks up, you've probably got wear in the torque converter lockup clutch (inside the torque converter proper,) which is trying to "slip" under load. Since the TCC isn't engaged until it actually locks up, you won't notice until lockup in 3d or 4th gear.

Alternatively, the TCC solenoid is starting to fail - but those are typically an "all or nothing" deal and you'd just not lock up, if that was the case.

I'd probably check the torque converter first. The TCC clutch is NOT in the transmission case, so you don't have to break it down to get there. If I had any more tips on diagnosis, I'd give with them - but I usually deal with stir-yer-own gearboxes...

5-90

Does anyone know under what conditions the converter is supposed to lock up? Any particular speed? Throttle steady? What gear?

3rd or 4th gear, light throttle

and typically around 43-45 mph.

Is it the same when it locks up with 3rd gear selected ? The revs don't drop quite as low when the lock up happens in 3rd.

I personallly think the change up to 4th followed almost immediately by the TC lock up is bloody annoying.