Shimming Center Support Bearing....Reduce Shudder!

[JJW_ND]

Those that have shimmed their center support bearing ("hanger bearing") on a long box Ext cab truck..... how thick of a shim did you use?



Can one use too thick of a shim (1/4", 1/2") and make it worse?



The shim goes between the center support bearing and where it bolts to the support, correct? I would guess one needs longer bolts?



I just had my driveline RnR at 205K miles on my 96 5sp. Replace the factory joints even though they had very little wear and were not dry yet. First time anything had been done to the driveline with lots of hard miles. The CSBearing was fine and left on.



I still have a shudder at low rpm (1400 - 1600) and heavy foot.



Thanks for any help.



jjw

ND

 

[redram]

If you have ashudder and have nursed 205K out of the OEM carrier bearing for the two piece drive shaft, I'd be inclined to install a new one.



Mine failed at about 80K and I was able to find a replacement from a driveshaft repair. Of course, Dodge engineers could not use a standard off the shelf already available bearing, they had to go and modify one so they could come up with a unique (read that more expensive) part.



From the drive shaft place, using probable a Spicer-Dana part, I think I had the support bearing installed for less than 60 including the new bearing and rubber flex donut with bracket.

I now have 134K and all is well with the driveline (96 3500 SLT 2WD)



Your shudder may be the result of weakening of the rubber grommet around the support bearing.



Good luck

 

[wtrenholm]

Chrysler had TSB's dealing with acceleration shudder on the mid 90's pickups. If I rememeber correctely it dealt with changing pinion angle.

Usually was an issue with loaded truck or towing,

due to the diff housing winding up.



I did do a couple at the dealership and it seemed to be a trade off where you could feel some shudder. On one, I cured the shudder while towing, but picked us some shudder unloaded. My 94 2500 gasser has shuddered slightly on hard accel with a trailer since day one, it doesn't bother me at all.



I would think someone has more recent experience with this.



HTH

Wayne

 

[Joseph Donnelly]

Universal joint angles are affected by the shimming and are related to shudder.



Also, if the joints are not perfectly in phase, you will have problems. There is the possibility that either an end was welded onto a driveshaft slightly out of phase, or the two piece shaft was assembled one spline off (or more), or a shaft has a dent in it.



My 97 with 2 piece shaft has no such problem with well over 100K on the clock and all stock u-joints and center bearing.



Another vibration problem, usually worse in deceleration, can be caused by bad pinion bearings in the diff.



Hope some of this will help with your specific problem.

 

[Steve Campbell]

JJW-ND, I shimmed my carrier bearing. I felt that the amount of play in the rubber "grommet" was excessive. My "shim" went inside of the bearing assembly above the rubber grommet. I believe it was a piece of flat bar 1 1/4" x3/16" x I do not remember how long (just long enough to fit into the assembly).



Two things: #1---3/16ths was plenty of thickness

#2---heavy throttle below1800 Rpm is just kind of hard on things.



All of that is JMO. Steve

 

[JJW_ND]

Finally back....

Thanks for the tips... . My shaft was all stock and developed the shudder shortly after replacing the 5sp with a 2000 (new style) transmission. I recently had a shop replace the unjoints and balance. High tech computer balancer.



I remember lots of suggestions to ship the CSB to reduce some shudder.



My CSB was fine (shops opinion). I do think the rubber support is getting tired. Might try adding some metal to the top side to compress the rubber support a little.



BTW... . I try real hard to role the throttle below 1800 until 2000RMPS. The and only then WOT as needed of course.



jjw

ND