1995 3500hd New To Me... Vibes At Speed...

KargoMaster · April 13, 2008

New to this site... I have searched around a bit for mid 90's "3500HD" information, but was finding lots of posts from years ago, so I thought that I would introduce myself and share my questions...

Ok, so I just got a new to me tow vehicle... 1995 C3500HD CrewCab C&C -- 454/4L80E... given my searching on this site, I have a feeling that there are folks here that are familiar...

This was right when I bought it about a month ago...

Brr, looks cold.

Some vibes at speed, didn't really bother me (as I just ASSUMED driveshaft, and easy fix), but wanted to take care of it as I want this to be my tow vehicle for highway use. Went to my driveshaft shop (yes, I have a favorite driveline shop.. more about that later) and had him rebuild the three piece shaft with all new 1410 joints and carrier bearings. Given the different (ie - non-Spicer) u-joint on one end and the two different types of carrier bearings, I suspected that it may not have been that way (3-piece) when delivered... He confirmed that indeed, one type of carrier bearing was specifically aftermarket.

Question 1: Anyone else with this style truck have a three piece driveshaft?

BTW, the vibes were specific to a speed (not an RPM) and just seemed to have the phase of something spining far faster than the wheels... this is why I pegged driveshaft..

So my vibes have decreased, but not yet evaporated completely as I thought they might given the full service joints/carriers/balance treatment that I got from my driveline guy. So I have to look up the driveline a bit... (sounds/feels like under me while driving, and not way back at the Dana80... besides, it's a DANA80...) I have the e-brake drum on the output of the transmission...

Question 2: Anyone hear/have the driveline e-brake drum that is attached to that tranny output (and SPINS with the driveshaft) cause vibrations in the driveline? (How the heck would I balance that?)

From there I look at the 4L80e... have yet to reaserch that one... so can't really ask an informed question...

Another option is to rebuild the first two pieces sans first carrier bearing and with one piece of tube (should decrease complexity at least) and see if I see additional gains.

Just feels like I'm missing something... Anyone??

Last Question... Anyone know of a Service Manual for these (C3HD??) trucks?? (Haynes and others are specific about NOT including them, with good cause... [cough: completely different suspension])

These trucks do seem a bit "red-headed-step-childish."

Oh yeah, Hello World, from Cincinnati, OH...

hubbycap · April 13, 2008

What speed(s)?

pennzoil29 · April 13, 2008

I've had carrier bearings do some funny things to an old '74 I had. I replaced everything from, tranny mounts, u-joints, carrier bearing, motor mounts and balanced the drive shaft and I still had a vibration. I lived with it for awhile, and finally got rid of it. The truck, not the vibration.

KargoMaster · April 13, 2008

What speed(s)?

Seems worst at 60-70, at 75 it's smooth as glass.

35-40 seems like less, but some vibration...

Thanks for the replies...

hubbycap · April 13, 2008

What speed(s)?

Seems worst at 60-70, at 75 it's smooth as glass.

35-40 seems like less, but some vibration...

Thanks for the replies...

Sounds like a bent wheel to me. If you don't feel it in the steering wheel, probably a rear. Jack up the axle and spin in gear and look for wobble/hop. Moving rear wheels around can get you to a point where there is a complementary wheel on the same side.