How much play in the carrier bearing is OK?

What are your rear springs like?

 

How old are your tires? They could be wearing unevenly. I had a vibration around 65 that went away when I put my winter tires on. Might not be the case with you but it’s worth mentioning.

 

My rear springs are 15 years old with 92K on them. They’re not really frowning, they’re merely smirking. Tires are fairly new, I’ll have to dig up the paperwork on them, IIR they have maybe 7k miles on them.

 

Any slop in your pinion going into the third? That will also do it. Maybe check the runout of the axle?

 

You mean the pinion in the differential? Hadn’t considered that. Should be easy enough to check when I drop the driveshaft.

 

Yeah. I had a bunch of vibration that I thought was coming from my carrier bearing, but also had quite a bit of gear noise coming from the rear end when I’d let off of the throttle. Pinion was moving side to side and up and down a solid 3/8’s. Put a new carrier bearing in and had ECGS rebuild my third at the same time, so can’t say which one was the culprit. I suspect both contributed to the vibration.

 

I replaced it. But the flange fell off the driveshaft (funny story unless it happens to you) before I put a match mark on it so the driveshaft is probably a little out of phase.

 

I hope that’s it. Im still pretty pissed at myself for letting the flange fall off to begin with. It was hot and humid when I did the center bearing and by the time I got the drive shaft out and flange loose, I was tired of crawling around on the floor. Was carrying the shaft over to he workbench and it hit the front marker light. When I spun around to see if I broke the lens the flange slid off. I was like JHC I’m 2 stooges short of a comedy.

 

I can be a special kinda of stupid sometimes. When I replaced the coilovers this weekend I cleaned up all my tools put away the jack and stood back to admire my handy work and looked at the truck and thought WTF I picked up like 4” of lift and the truck is sitting crooked AF. Turned out I forgot to take the jack stand out form the passenger side. Like I said, a special kinda of stupid.

 

I think all the grease fittings are supposed to pointing the same way from factory.

 

I went by this and the match marks I had on the transmission and differential ends of the driveshaft. Could still be off by a couple of splines on the flange.

 

Took the garage queen out for a couple of 70 MPH runs on the expressway yesterday. Having done nothing else except replace the original front coilovers w/Monroe Quick Struts the gawd-awful shaking at highway speeds seems to be gone. Still felt a little vibration that I suspect it from my hosing up the drive shaft. Wondering if problem all along was suspension and not driveline maybe wind buffeting the tonneau at highway speeds sent the whole truck bouncing on worn out pogo-stick suspension. Rear shocks, tire rebalancing (again) and driveshaft rebalance still in my immediate future.

 

Fixed! Replaced the rear shocks. Made all the difference. The OEM shocks that came off would slowly compress under their own weight when I held them straight up. I had to put all my weight on the new ones to compress them and I was afraid the truck would ride like a red flyer wagon but rides great.

 

Glad to hear you got it fixed!