My truck shudders when starting out. It's really bad starting on a steep hill or pulling the travel trailer from a stop up a grade. Once I get rolling everything is fine. I just replaced the center u-joint, the one at the t-case is fairly new and the u-joint at the diff. has no slop.
I was wondering if lowering the center bearing, like I've heard about, would correct this?
Would the limited slip cause this?
The truck has the A518 auto.

 

I don't have any personal experience with this, but my impression from what I have read is that if you have a bad drive shaft angle it will keep vibrating at higher speeds. Still, if it looks like you have a bad driveshaft angle, putting a shim in to lower the carrier bearing wouldn't hurt.

 

Try puting a 1/2 inch shim in between the carrier bearing mount and the frame. This might help. There was a TSB on this which included a wedge shaped insert being placed between the springs and the spring mounts as part of this TSB. Some have found that the 1/2 inch shim helps.

It was a real bear on the manual trannies.

Bob

 

Didn't Dodge have parts for lowering the carrier bearing? Do you know where I can view that TSB?

Thanks, Chris

 

how about a torque convertor problem? I'm just guessing per other applications I've seen shudder b4. I know early 80's lockup convertors in 904's and such tended to hang up and shutter

 

The TSB is at http://dodgeram.org You can click around and find it. The spacer helped my truck, but it's a 5 speed. I don't know how an automatic's throttle cable is routed but after fanaggling mine so it didn't touch the brake booster it REALLY helped. It is not supposed to touch anything but the firewall and the mount. It will move the arm on the pump slightly and cause shudder problems. (at least on a stick). Good luck, Jim ;D

 

Trans. problem? Don't want to go there!! I've got a fairly recent rebuild and I know I don't have a lock-up convertor.
I don't have time tonight to search for that TSB, but I will later. I'll also check on the throttle cable.
Thanks, Chris

 

My money's on the tranny.

ramguy

 

Hey ramguy,
You sure know how to make a guy feel bad :'(
Hope you're wrong! If it is the trans. what do you think it is? I'll need some info./ammo for the tranny shop.

Chris

 

Hey Bigredbrick,
My 92 Ram250 has just started this very thing in the last several haulings, Not too heavy of a load "~8500lbs"
I found it only to be associated with first gear though! My money is on a wore 1st gear clutch pack.
I have not serviced the trany yet. Keeping fingers crossed that some fresh fluid will help.
Does any one know if these clutch packs are adjustable?

Cheers
Astromybud

 

My 93 built in June 0f 93 came with that center steady bearing spacer in it.
Check to see if yours has it. If not, get it put in. Next would be the universals. I know you've replaced one or two but they can be bad and still not show signs by "hand checking".

The tranny is possible since you've had work done recently but I'd eliminate the other things first. That way, if you can't fix the problem you can go back knowing that they can't use those as excuses in the event it is tranny related.
Most reputable trans. shops will be able to determine if there is a problem internally.
Make sure you haven't lost any wheel weights, or drive shaft balance weights too..
Check the drive shaft for "new" clean spots or sign of a lost balance weight. That does happen more than you'd think.
Besides, it's cheap/free check out....
The last item would be to make sure that the drive shaft was put back on properly indexed. During the universal replacement or the tranny in/out job, the D-Shaft could have been put back 180* out of phase.
bob.

 

How about a broken motor mount????

 

astromybud
A fresh fluid will not fix a broken transmission, and there is not an extrernal adjustment for clutches. Pull the dip stick and look at the condition of the fluid, should be cherry red and clear (no junk floating in it),also smell it, if it smells burnt - it is. addition service required.

 

Thanks for the input. Your replys have got me thinking about the possibilities.
When I bought the truck 2 1/2 years ago it had a very slight shudder on take off which turned out to be the t-case u-joint.
No problems til last summer when towing the trailer (6,000 lbs gross) plus bed full of gear with steel shell and family of 5 stuffed in the cab. This was after the trans. rebuild.
Recently replaced the sloppy center u-joint, the slight shudder persists.
I could live with it, until I left my sister's house with a very steep driveway. It shook so bad I thought I was going to drop something right there.
My truck with a build date of 9/92 does not have a spacer to lower the carrier bearing. Does that spacer go btw the frame cross-member and the c-bearing mount or btw the mount and the c-bearing? Bushy, does your truck have tapered shims btw the springs and rear axle? I suspect that this won't fix it but am willing to give it a try. I'll check for lost weights, but I didn't notice them missing 2 weeks ago. Also, shudder goes away once up to speed, low or high.
How do you check for a broken motor mount?

Thanks, Chris

 

Might help to know what you are shooting for. The three universals need to be the same vertical angle. You could even make a gage to check it with a little bullet level and some sheetmetal. Get it so the level is on one and the other two should be the same. Sounds like the rear trans mount may be setteling down some. Curing those angles are by raising the trans mount, adding a spacer at the center joint and wedge plates at the rear axle depending on which is out of line.