Rear driveline vibrating and grinding alot

iant333

Member
Yeah this has been the case since I installed my new rear springs and gears a few weeks ago. I figured since when i did the springs I took the shims out that the pinion angle was off. Well I made the pinion angle perfect today and it is even worse, like noticeably worse so apparently the pinion pointing directly at the transfer case was better than it actually being correct.

It grinds when it is coasting, like pretty loudly, it makes almost the exact same sound as when the slip joint on my front shaft was bad. Once you get on the gas the grinding stops but it vibrates really harshly at any speed over 45 and it seems to come in waves and get better and worse over a cycle of like 5 seconds, the vibration is actually so bad I cant see out the mirrors at speed since they are shaking so much. There is also a ton of slop when im driving it, if you are coasting it takes half a second to catch once you get back on the gas.

Im almost 100% sure it has nothing to do with the gears, the pattern and everything was perfect when i installed them and they still look fine now, I have an Aussie in the back which might explain some of the driveline slop but it was all in spec when I installed it. Obviously it isnt anything to do with the pinion angle, all the u-joints are fine and nothing really looks out of the ordinary.

Im at a total loss for what to even look at next besides just throwing the whole thing in the trash and getting a SYE and new shaft and hoping that somehow it might fix it. Any ideas? I'm thinking maybe it is something in the transfer case is screwed up and it just happened to appear around the time I did all this stuff to it.
 

scottmcneal

The 97 Club
NAXJA Member
How long did you drive after installing lift? Couple of weeks can kill u-joints..Make a cap for the rear shaft yoke, remove shaft and drive to see if the gears or something else..
 

iant333

Member
How long did you drive after installing lift? Couple of weeks can kill u-joints..Make a cap for the rear shaft yoke, remove shaft and drive to see if the gears or something else..
\

It was lifted before I just rearranged the leaves and put another leaf in it. And it started right away. Im gonna pull the shaft though and see what happens.
 

jakeWI

New member
i had the same issue (just not as bad as you) when I installed a RC 4.5" lift on my 1996. The pinion wasn't to bad and either were my u-joints. Haven't figured it out on my 1996 since it is now in pieces.

When I had my 1993 lifted same never had issue.

I was going to suggest U-Joints because had that problem once.

Have you checked your yoke? I know kind of random. I had another similar problem but I busted a tooth off the axle yoke that time.
 

iant333

Member
i had the same issue (just not as bad as you) when I installed a RC 4.5" lift on my 1996. The pinion wasn't to bad and either were my u-joints. Haven't figured it out on my 1996 since it is now in pieces.

When I had my 1993 lifted same never had issue.

I was going to suggest U-Joints because had that problem once.

Have you checked your yoke? I know kind of random. I had another similar problem but I busted a tooth off the axle yoke that time.

Yoke is brand new.

And yeah I took the rear shaft off and drove it, the noise stopped. But im not really sure if that actually rules anything out since if the rear end was the issue the driveshaft is probably what accentuated it and made the sound. Im really thinking it isnt the geras though since if the gears were making that kinda sound im pretty sure they wuld be all eaten up and look like shit but they look just fine and still run a good pattern.

Anyways I think im gonna SYE it and run a front shaft and see if that fixes it rather than try and make the stock setup work. Hopefully whatever the issue is should be fixed when I do that.
 
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