So, 3 weeks ago I parked the old girl. Had a transmission issue, throw a gov sol and press sensor at it, made a front band adjustment and it started shifting again. It had locked itself in third (limp mode) did these repairs at the recommendation of my shops transmission rebuilder. Like I said, it shift again thank god, little lame as my tv cable is out of whack right now but it’s shifting. My issue is it’s vibrating and shaking on deceleration, did this before the repairs. Driving at steady speed it’s good, decel is baaaddddd, what should I check?

 

Start with checking all the u-joints and slip joints in the drive shaft(s).

 

could anything in the transfer case cause this as well? I had a cracking sound upon changing from park to drive or reverse that disappeared randomly

 

Maybe. But, not real likely. There was a problem with a snap ring on the t-case output shaft coming loose, and allowing the shaft to walk in the t-case, that tends to grind up parts pretty quickly, but, was more of an issue when under power, not coasting.

 

Im going to check u joints and such and throw 4 tires and an alignment on it and hope for the best. It’s not transmission related I don’t think, doesn’t seem likely to shutter under coasting

 

As said before check u-joints. When I get a used 4x4 truck with over 100K miles I change/swap them out with new ones.

Pinion bearing? if it's more of a whirring sound. It starts out with a small sound and as the bearing starts to wear more it'll start to get louder. After a while it'll start vibrating where it's really noticeable and you can feel it through the pedal/butt. You can go 100 miles or 100,000 miles if you don't mind the noise.When it starts a chunkachunkaachunka, it needs looked at. Is the oil level in the differential/pumpkin full to specifications? When was the last time it was changed?

The clutch packs in a differential/pumpkin will chatter if you have a posi/limited slip when they wear out. Also when the wrong oil is in there. You'll feel this mostly going around corners.

 

I was just in the axle changing spider gears as they were making noises, pinion seal and bearing were tight at the time so I didn’t change them out, maybe it’s that. I really didn’t think about the pinion at all

 

alright, pinions still tight, trans mount and u joints look good could it all be front end/tires...? Maybe try a different driveshaft too maybe it tossed a weight

 

A heat shield rattling somewhere? Does the driveshaft show where a weight might have been? Did you go under and see if the pinion will move side to side, up and down? It shouldn't. Rotate is cool though so long as it doesn't have 1/4 of rotation slop. You'll feel the vibration from a thrown weight all the time, accelerating, coasting, cruising or slowing. This is what I would do and unsafe, I'd use 6 ton jack stands under the rear axle just so the rear tires are off the ground, then start it up and see if the noise is still there, or where it's coming from. I'm still going with the pinion bearings. 4x4?, then I'd disconnect the front driveshaft at the transfer case first, then put the rear up on 6 ton jack stands...., noise gone away? I'd pull the front drive shaft completely and take the truck for a cruise to see if the noise is still there or gone. If no noise then the front is the culprit because the front axle isn't under any power/torque. OR the front DS u-joints are messed up.

Is there a cheap lift kit on it?