Pinion yoke loose, is the bearing ruined?

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462
Location
Kentucky
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I've got a 1991 R1500 Suburban with a 10 bolt rear axle. The pinion seal leaks and recently I've noticed some vibration at low speed under high acceleration. I thought some u joints might be going bad, but as I was down under the truck pulling back and forth on the driveshaft I realized the pinion yoke could move back and forth just a little. Do you think I could just pop on a new pinion seal and tighten up the nut some or are the pinion bearings shot and the whole thing need rebuilt?
 
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4,841
Location
Columbus,Nebraska
I believe that uses tapered roller bearings which have to be preloaded to certain spec. I wouldn't expect any play at all in the pinion as that would change the mesh with the ring gear.
 
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21,115
Location
Apple Valley, California
It uses a crush sleeve to set pinon load. If you need to replace the pinon seal your supposed to replace the crush sleeve. Nobody does. They replace the seal and run the nut up till it's right.
 

Kestas

Staff member
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13,735
Location
The Motor City
As said, you could tighten up the nut and hope for the best. When there is too much clearance, taper bearings see a wonky load pattern that can easily damage the raceways.
 
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6,642
Location
South Florida
Shake the driveshaft up and down. Is there a lot of play? I had one that was so bad you could shake it up and down a half an inch. It was a mud truck so I didnt care to fix it.
 
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462
Location
Kentucky
Thread starter
Thanks for the replies. I will try a new seal and tightening up the nut. Even if it doesn't work, there's not much to lose by doing it. Anyone have an idea what torque spec I should aim for or how I should go about tightening it?
 
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1,425
Location
Perris, CA
When I did the pinion seal on my Xterra, the general trend I was reading was to mark the nut and the shaft and make sure the marks line back up when tightening everything back down. That's how I did it and it's been fine for over a year.
 
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4,230
Location
Parts Unknown
I would be prepared for more than a simple seal change. If you ran bad u joints long enough, it's possible to screw up the pinion bearing. That nut is torqued very tight and I can't believe it just loosened up for no reason.
 
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2,178
Location
NY, NY
Originally Posted by Lubener
I would be prepared for more than a simple seal change. If you ran bad u joints long enough, it's possible to screw up the pinion bearing. That nut is torqued very tight and I can't believe it just loosened up for no reason.
This. I have never seen a pinion nut just loosen.
 

Astro14

Staff member
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11,364
Location
Virginia Beach
New seal AND new pinion bearings, properly set up (preload and/or crush washer) are likely what you need. Tightening that nut on a worn bearing is only going to accelerate its demise.
 
Messages
462
Location
Kentucky
Thread starter
The u joints seem fine.I am going to try tightening up the pinion nut a bit. I guess I'll mark the nut and bolt. Take the yoke off, replace the seal, put the yoke back on and tighten everything down to were it was. Then go a little further until there is no play. If that doesn't work and it starts leaking again or starts making noise then I'll know it's time for new pinion bearings. I'll also check to make sure the breather tube is unobstructed.
 
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1,114
Location
PEARL River la
S10 10 bolt rear end pinion nuts come loose after higher miles so a rebuild is always best but can't tell you how many times I have seen customer say tighten up the yolk and let it go for now. Most never come back. I did one that I changed seal and tightened then 200k later he came back for a leak and just installed a seal. He sold truck with 690k.
 
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462
Location
Kentucky
Thread starter
Just an update on this. I went ahead and replaced the seal and tightened up the pinion nut with some lock tight. I believe it's somewhere from an 1/8th of a turn to 1/4 tighter than before. There was more noticeable play than I thought when it still had the driveshaft on. I tightened the nut bit by bit, turning the pinion some after each time and pushing it back and forth to see if there was any play. When I was done, the pinion still turned easily so I don't think I overdid the tightening. I'll check it again in 500 miles or so. I also needed to change an axle bearing on the driver side that was leaking and had noticeable play in it. I had gotten a nice skf repair bearing but when I got the axle out, wouldn't you know that the previous owner had already put an elcheapo advance auto repair bearing in, and put it in backwards completely ruining the axle. So now I'm waiting on a new axle, bearing and seal from rock auto. [Linked Image]
 
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Messages
462
Location
Kentucky
Thread starter
A quick follow up on this, I've gone about 2000 miles so far on the new axle and axle seal and pinion seal. No leaks or issues so far. I used SDK seals and bearing and the cheapest new axle I could find a DANA SVL one for about $60.00 from Rock Auto. I used gasket shellac around the edges of both seals and waited a day before refilling with oil. I checked the tightness of the pinion about 2 months ago when I was replacing the u joints and it was still good, the nut hadn't moved. It's safer to say mission accomplished on this one.
 
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