Could my pinion possibly be causing vibrations?

[starkey480]

I’m chasing down a 70mph vibe. My pinion has two different backlashes, a little one and the obvious bigger one that comes from having a spartan locker. Is having that smaller amount of wiggle normal? About two months ago my pinion nut came loose. This concerns me. I torqued it down to the correct spec. My vibe seems to be getting worse.
This is the last thing I can think of on my vibe checklist.

• I have no vibes when I take out my front driveshaft.
• I've had the shaft balanced and rebuilt a year ago.
• Tires balanced
• Axle u-joinst look good
• Pinion angle matches driveshaft angle (both at 7.5 degrees)

The only other thing I can think of is the gears or pinion bearing are messed up somehow

 

[someguysjeep]

that don't look right to me.....that tiny bit of play is normal.
that inch of turn seems very odd .

i'm sure others will chime in.
@hosejockey61 can give some insight.

 

[CharlesHS]

Since the Pinion nut came loose a month ago and even though you tightened it to spec; how long was the pinion nut loose and what damage may it have caused in that time frame ?
I would drain the rear differential gear lube and look for sparkles floating in the gear lube.
Even though you had the front driveshaft balanced, vibrations can still exist due to a worn slider assembly or double cardan joint centering section.
You can contact forum member Mr.BLAINE for his words of wisdom.

 

[Goatman]

×2
Pull the cover and see what is going on. The pinion nut should never work itself loose if everything was done right during assembly.

 

[starkey480]

that don't look right to me.....that tiny bit of play is normal.
that inch of turn seems very odd .

i'm sure others will chime in.
@hosejockey61 can give some insight.

That large backlash is the backlash in the spartan locker. Similar to a Detroit. If the little play is supposed to be there then I feel a little bit better

 

[starkey480]

Since the Pinion nut came loose a month ago and even though you tightened it to spec; how long was the pinion nut loose and what damage may it have caused in that time frame ?
I would drain the rear differential gear lube and look for sparkles floating in the gear lube.
Even though you had the front driveshaft balanced, vibrations can still exist due to a worn slider assembly or double cardan joint centering section.
You can contact forum member Mr.BLAINE for his words of wisdom.

×2⬆
Pull the cover and see what is going on. The pinion nut should never work itself loose if everything was done right during assembly.

I will pull the cover and check it out

 

[starkey480]

Since the Pinion nut came loose a month ago and even though you tightened it to spec; how long was the pinion nut loose and what damage may it have caused in that time frame ?
I would drain the rear differential gear lube and look for sparkles floating in the gear lube.
Even though you had the front driveshaft balanced, vibrations can still exist due to a worn slider assembly or double cardan joint centering section.
You can contact forum member Mr.BLAINE for his words of wisdom.

Ok so pulled the cover and no sparkles. The backlashes I was seeing are just the backlash of the pinion and ring gear and the spartan locker. Everything looks completely normal inside. I’m not sure where to look next for my vibes

 

[starkey480]

Fixed the vibes. It was just pinion angle. I need a new digital angle finder

 

[CharlesHS]

Fixed the vibes. It was just pinion angle. I need a new digital angle finder

Good to know it was something easy to fix that didn't cost much...

 

[hosejockey61]

Glad you got the vibe figured out. Just so you know, pinion nuts are supposed to be one time use (Stover nut). Some people say they have success with loctite on them. If a pinion nut is reused, you risk the nut coming loose and internal diff damage. They are a few bucks, get a new one.

 

[Goatman]

Always make sure you get all parts back anytime you have a garage do work on a vehicle. That's the only way you can be sure they actually used replacement parts and not just reused the old ones. Be sure they are not the old parts from another vehicle they have in the back.
I can remember a time when a handshake was a legal binding agreement. Then it was just a man's integrity. Now they want to make a handshake illegal! Hard to find a shop you can trust. They promise to do everything by the book, then you get home and find the lug nuts need a 5 foot breaker bar to loosen.