Here is the scenario: New to me truck, in sig. At Idle, it has a harsh vibration. Not like a mis fire. give it a little fuel and it smooths right out. It does it in Park, Neutral, Reverse, Drive while stationary. It also is occurs when driving. For example, driving along, accelerating to highway speed, when the truck shifts up to next gear and the RPMs drop, vibration comes back, but as you speed up it goes away. I am suspecting a bad torque converter, not balanced converter, or some installation problem between converter and flexplate. It is NOT drive line related, like wheel bearings or ujoints.
A little history: I bought the truck used, but with a new Reman. Chrysler transmission installed at dealer. It has warranty. The dealer im closest to now, wants to remove trans and run the engine. basically, he wants to isolate the problem. If truck runs smooth w/o trans attached, they said they will order a new transmission and converter and all will be covered under warranty. However, if its not the trans(and in the engine) I will be responsible for the tranny remove and re-install. Approx $700.
The head tech said just drive it until some thing fails, either it will be warranty or it wont. lol
I've checked the truck over, cant find anything out of ordinary that would cause vib.
Suggestions? Thanks.

 

They should be able to unbolt the torque converter and start it without removing the trans.

That would be a good start.

 

That's what I thought, but DC told them to start there.
I could do that. IM almost 99% sure its in the trans/converter. but im not a gambler. don't wanna risk the 700$ to be wrong,

 

Pull the inspection cover and crank up the truck. Use chocks and all the safety precautions you can. Climb under and see if the TC is doing the Funky Chicken. If so, the converter was bolted up with final tq, one TC bolt at a time and the Converter is cocked and not aligned properly on the flexplate. Remove all the bolts, one at a time. If the converter slides back on it's own, this was the case. TC bolts must all be put in one at a time without the final torque. Once the converter is slide all the way forward, then the bolts should be tightened to torque specs. This means it was an install issue and should be covered under warranty.

 

cool thanks. That makes sense. Im prob just going to have this dealership look into it when I get back to Colorado. IF I get back to Colorado and it doesn't breakdown. I think the vibration is getting worse, especially in higher gears after it shifts. The diesel/truck tech there seems to know his stuff and I felt comfortable with him working on it after talking with him. Id take care of it, but don't wanna risk losing warranty. Thanks again and Happy Thanksgiving.

 

I agree with Spooler but it depends on your technical skill....

Get the truck up on jack stands, run it through the gears trying to narrow down the vibration.

- Is it RPM or speed or gear dependent?
- 2wd or 4wd?
- Pull the torque converter cover, check the bolts, visual inspect it for vibration.
- watch the driveshaft(s) as they spin.
- check all the U-joints.

Pull the rear driveshaft, inspect the U-joints, run the truck down the road in 4wd without the rear driveshaft.

IMO, I would only take it to the dealer as a last resort. The less time your truck is at the dealers the better of you will be.

 

Vibration is present at idle: in park, neutral, reverse, drive all while sitting still. It is not u joints, wheel bearings, Etc. i already troubleshot it that far. I could unbolt it and work on it, but like I posted before, It has Warranty I'm not working on it unless I have to. Thanks.

 

I thought in the past I have read of some Harmonic ballancers (front pulleys) comming apart and rotating out of ballance on a couple threads in here, might want to read up on this.

 

I took belt off and ran truck. Still vibrated. so, only pulley was crank damper. It looks in good condition, alignment marks are still in line, rubber looks good too. I know that doesn't mean its fine, but im still leaning toward TQ/flexplate.
Cummins has damper for around $150. it may be good PM for me to just change it now.

 

100 bucks says it is how they bolted the TC up to the flexplate. How do I know. Mine did the same thing when I had my tranny upgraded. Tech got in a hurry I guess. I pulled the TC bolts and the TC slide back on it's own. Rotated the engine 180 deg. and bolted it back up like I said one at a time after I slide the TC all the way forward. I got your exact same symptoms.

 

thanks. Im going to take it in soon, I hope.
Am now getting a shudder in my trans now too, occasionally. errrrggg.
Supposed to go snowboarding this weekend. Getting pretty good snow storm now, im gonna need 4wd.