I have a '99 Cherokee with 245k on the clock and I think my torque converter needs to be replaced. At idle the whole truck shakes like it's a cylinder down. I pulled one spark plug wire at a time and all the cylinders are firing. There is no CEL code. The truck shakes like there is a weight missing on the torque converter or flywheel badly until the torque converter lockup occurs. When the converter locks up (around 45mph) the shake goes away completely like nothing happened.


Does this sound like a torque converter? If so I have an '88 AW4 I can rob it from if they are the same.

 

Could be the TC.


Remove the inspection cover and see if all 4 Flexplate to TC bolts are there and tight, and see if the flexplate is cracked.


The 88-01 AW4 Torque Converters are the same. P/N 53003431.


But, do you think it's worth the effort to install an antique TC (88)?

 

Thanks for the advise, I'll check the bolts, seems strange that the noise/vibration would go away completely when the converter locks up though. As for the '88 it's just sitting in the storage unit so not too much effort. Better than paying $190 for a reman one, if it works.

 

I do have to add that when the truck sits for two weeks or a month when you put it in gear it takes some revving to get it going. It's like the pump isn't pumping enough oil and the trans is full.

 

Try this Cold Fluid Check.


It has revealed a bad TC in the past.


When replacing the TC make sure you use Dexron III/Mercon (DEX/MERC) transmission fluid at refill.



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I agree with above post I would never replace the TC (if in fact it is bad) with an old used one when you can buy a reman for so cheap check around for prices.

 

What I meant when I said "have to add" meant in addition to, not add fluid. I have checked it and it's been full. I'll check it again since it's been a while lately.

 

Do the cold fluid check.

 

Okay, so I did the cold start fluid check and it's just what it shows in the pictures above. I checked the fluid before I started it and it was above the full mark, and then when I started it I checked it and it was at the add mark. So what does this tell me?

 

That looks good. As far as to what it means, I'd say the TC is working to run the transmission oil pump.


Did you inspect the four bolts that secure the TC to the flexplate?




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Yes I inspected the torque converter bolts / flywheel bolts they were tight. I drain the transmission fluid and it was dark color smells normal to me. I ran the truck well underneath on jack stands and the whole driveline was shaking. Do you think a very loose transfer case chain would cause this condition?

 

I haven't check the compression on each cylinder yet, but I can't imagine that it would be lacking sense the problem goes away as soon as the torque converter locks up at 45 miles per hour. The harmonic balancer look good too.

 

I guess I could take the torque converter bolts out and push it back and run the engine to see if the engine still shakes at idle.

 

I took the 4 bolts out of the torque converter pushed it back started the engine and it runs smooth.

 

Have you checked the security of the four bolts holding the bell housing to the engine?


If the are okay, there may be a mechanical fault in the TC causing the vibration when not locked up. Which is odd because the TC clutch
engagement occurs in second gear in 1–2 position, third gear in 3 position, and third and fourth gear in D position.


Manually select 1-2 and see if it vibrates, then select 3 and see if it vibrates.


Remove the transmission oil pan and screen. See if there's chunks in the screen.