Have I spun my diff housing?

[Mike Pierson]

So I’ve been dealing with a bad vibration in the rear I’ve had since the Shaver Lake run. Starting with the cheapest things first I had my wheels balanced, and they were “significantly out” according to Discount Tires. Had my drive shaft tested for balance and it was still perfect. Checked my rear axle shafts and they were bent. So bought and installed new rear chromoly axle shafts but that didn’t fix the problem either. Not a wasted effort since I needed to upgrade them anyways.

Turns out it’s the pinion angle. I never even considered that because of how stout the EVO longarms and brackets are. Measured it yesterday and the diff was pointing up and off by a whopping 5 degrees. I can’t imagine how that could happen since I’m not heavy on the throttle and have not hit the pinion or drive shaft on any rocks. I used the upper adjusters to lower it but had use up the entire allotment and i’m still 1.2 degrees off. Now I have to reset the adjusters back and extend the lower control arms to get it back to zero.

Have I spun the diff somehow? Why else would the pinion angle go off center so much? How can I check for this?

 

[AZVAJKU]

I think this is the only solution Mike.

 

[Disciple Off Road]

So I’ve been dealing with a bad vibration in the rear I’ve had since the Shaver Lake run. Starting with the cheapest things first I had my wheels balanced, and they were “significantly out” according to Discount Tires. Had my drive shaft tested for balance and it was still perfect. Checked my rear axle shafts and they were bent. So bought and installed new rear chromoly axle shafts but that didn’t fix the problem either. Not a wasted effort since I needed to upgrade them anyways.

Turns out it’s the pinion angle. I never even considered that because of how stout the EVO longarms and brackets are. Measured it yesterday and the diff was pointing up and off by a whopping 5 degrees. I can’t imagine how that could happen since I’m not heavy on the throttle and have not hit the pinion or drive shaft on any rocks. I used the upper adjusters to lower it but had use up the entire allotment and i’m still 1.2 degrees off. Now I have to reset the adjusters back and extend the lower control arms to get it back to zero.

Have I spun the diff somehow? Why else would the pinion angle go off center so much? How can I check for this?

I doubt you spun the housing but anything is possible. Crazy it went up 5°. It would have done this from day one after the build so something changed for sure.

 

[Mike Pierson]

I doubt you spun the housing but crazy it went up 5°. It would have done this from day one after the build so something changed.

It’s been absolutely perfect since the build though, and I mean perfect. This only happened since Shaver. Bars aren’t bent, brackets aren’t bent or cracked. If not a spun housing, then perhaps the adjusters got pushed inward? That doesn’t make sense either because i measured from the johnny joint to the tube and both sides were exactly the same length apart. IDK

 

[wayoflife]

It’s improbable but have you checked the Johnny joints to make sure none of them are blown?

 

[wayoflife]

Also, 5 deg is REALLY off and should be totally visible by the naked eye. Can you post a pic of this?

 

[Mike Pierson]

It’s improbable but have you checked the Johnny joints to make sure none of them are blown?

Not a thorough check, no, but they don’t look to be broken. Thanks, I’ll check them when I redo the lengths.

 

[Mike Pierson]

Also, 5 deg is REALLY off and should be totally visible by the naked eye. Can you post a pic of this?

I already adjusted it, as much as I could last night, and yeah, it was clearly obvious when I got under there. Even where it’s at now, at 1 degrees off, you can see it.

 

[TrailHunter]

You've inspired me to put witness marks on my Housing & Tubes.

 

[jesse3638]

You've inspired me to put witness marks on my Housing & Tubes.

No need you're running 35's...haha

 

[OverlanderJK]

If your wife asks, you definitely spun it and need to upgrade. If it’s us, probably not.

 

[benatc1]

That’s interesting, did the correction eliminate the vibration?

 

[Mike Pierson]

That’s interesting, did the correction eliminate the vibration?

I didn’t have time last night to correct it 100%. It’s better now but still bad at highway speeds. When I redo the adjustments and get it to a zero degree difference I’m sure it will eliminate it entirely. Just not sure how it got off so bad in the first place.

 

[benatc1]

I didn’t have time last night to correct it 100%. It’s better now but still bad at highway speeds. When I redo the adjustments and get it to a zero degree difference I’m sure it will eliminate it entirely. Just not sure how it got off so bad in the first place.

Yea I’m sure it will too. Any visual signs on the welds on the rear tube diff? Definitely odd, but might explain the issue. Probably time to upgrade to that semi float rear 60 tho.

 

[jeeeep]

what did you say dear? couldn't hear you.
New tires and wheels? ohhh, no, I just washed and polished.
The tires look larger? hmm, no, they are cleaner.. ohhh, I put more air in them.
The wheels? no, they've always had 8 lug nuts.

 

[Mike Pierson]

Yea I’m sure it will too. Any visual signs on the welds on the rear tube diff? Definitely odd, but might explain the issue. Probably time to upgrade to that semi float rear 60 tho.

Haven’t checked for that yet, the thought just occurred to me on my way to work. Will be checking after work. Lol

 

[bobfriesenhahn]

I didn’t have time last night to correct it 100%. It’s better now but still bad at highway speeds. When I redo the adjustments and get it to a zero degree difference I’m sure it will eliminate it entirely. Just not sure how it got off so bad in the first place.

The parts that moved could move some more later.

 

[Mike Pierson]

The parts that moved could move some more later.

Yeah I was thinking that too. I’m going to re-measure for that before I redo the bars but if it truly did spin i doubt just driving on the highway would move it any further.