help! did some 3rd member work now vibrating

Alright, so I pulled the 3rd & had it looked at. Mechanic said no problems just old and a bit worn. Put it back in 3 weeks ago and have been driving it without incident since. Then this morning started to get a true rumble/vibration under load only. Nothing when coasting. Took a look down there and found that nothing that I'd touched had loosened, so then looked over the prop shaft and noticed the carrier bearing is cocked. Could this be causing vibration? I see it supposed to be square to the prop shaft?

 

It's definitely supposed to be square to the drive shaft.

 

Bad autocorrect - my coworkers email.
Please take that out of your post. Thanks.

Ok. I'll get that straightened out and see if it helps.

Thanks for the reply.

 

I don't understand how it could have gotten crooked. Is that an impact mark on the side that is pushed back? Are the two mount bolts loose?

 

Thanks jowy.

Dig, the holes are slotted.

 

Looks like when they put everything back on my new frame when they torque the bolt it twisted bearing mount

 

You said it started vibrating this morning. If it is because the carrier bearing is twisted, then yesterday (or whenever it wasn't vibrating) it wasn't twisted.

I realize there are slots, my question was how did it move in the slots. Are the bolts loose? Or did something (an impact) move it? Or perhaps, it has been vibrating for a while. Maybe since that last wheeling trip when you scraped across that one rock.

It id not just, out of the blue, twist on its own.

 

Correct. Bolts were tight, and the rust marks were clearly where it was bolted currently, so I suspect it happened when I got my new frame.

That said, I've straightened it, and it's changed nothing. While maneuvering it into the garage, noticed that shifting causes a metallic clunk&ping sound. Also, while out for the test ride after straightening it I noticed a metallic almost chirping sound coming from the rear end, which also occurred while coasting.

I'm starting to think that I should have just gone with a new 3rd, but I don't want to just start throwing money at it with it having 206k miles.

Does this accumulation of symptoms lead anyone to any conclusions other than the 3rd member?

Thanks for the help!

 

Does the chirp continue with the clutch in? I get it when I'm slowing in first or backing up, goes away with the clutch. It really sounds like it's coming from my rear diff but I think I'm just needing a new clutch/pressure plate.

 

Automatic.

 

Different then I'd check brakes and then move up the drivetrain. The only diff issues I've had have always been a grinding sound rather than a chirp of any kind, I have had worn brakes that made some high pitched noises whenever the wheels turned. Maybe jack and jackstand up the rear end so you can get under it and locate the noise.

 

By your description it really sounds like a u joint, vibrates under load and nothing while coasting....im suprised it wasnt the carrier, i woukd have figured that to be it. But since its ruled out it really smells like a u joint to me....but with the 3rd in question i suppose it cant be ruled out either...

 

ujoints can make a squealing noise...also I would think the carrier bearing should be in line with the driveshaft....not crooked like in the pic...sure it would work since its a rubber boot and the bearing in the middle but something is askew.

 

Yeah thats another reason i suspect a u joint problem.
OP fixed the crooked carrier btw...

 

Is there a u joint writeup for the 1st gens? How 'bout a parts list?

Thanks guys.

Any ideas about the clunk/ping noise when shifting between R& D?

 

Bump for follow up questions above.

Thx

 

There is definitely at least a couple good threads on u joints in here, one of which was active here not too long ago.

The clunk/ping could easily be a sloppy u joint??

 

Alright, so, since they're so cheap, I decided to go ahead and change the u joints and see what happens. Truck has 204k miles, they've never been changed, i live in the salt belt, and I've had dealer oil changes, so who knows if they've ever been greased.

Did a lot of research and this is definitely something I can do... however I had a hard time finding a comprehensive diy post for the 1st gens.

My question is... does the driveshaft & flage slip out of the t-case, or do I need to unbolt the flange.

Thanks!

 

The driveshaft bolts to the transfer case. I think 2nd gen driveshafts slide into the transfer case.

 

Job complete. "Clanking" while shifting: gone, vibration: gone, chirping: gone.

Also.found that dealer oil changes do not include driveshaft lubing. The grease, even in the good arms was black as can be. Took about 25 to 30 pumps to purge the DC u joints which was black as well. Will post pictures later.

Thanks for the help! Awesome site here.