GM 10 Bolt Rear Pinion Seal Change Gone Amuck

[Bohemian]

82 K5 Blazer...

So I thought I'd change my slightly leaking rear pinion seal today.

I dropped the drive shaft, zipped the pinion but off by impact & tapped pinion yoke off with plastic shot hammer no problem. Pulled the seal out no problem with handy dandy seal puller. Put the new seal in with big ass socket no problem.

My problem is the pinion yoke will not go all the way on. It goes on no problem to within about 1/4" of all the way and nothing will get it to go further. I can take it on off to that point no problem but it won't go on back as far as it was before I started.

Any suggestions?

Thanks in advance.

 

[Hogback Fabrication]

I'm guessing you don't know about the crush sleeve that's in there and its influence on pinion bearing preload?

 

[Bohemian]

I'm guessing you don't know about the crush sleeve that's in there and its influence on pinion bearing preload?

I am and I've changed these seals before, without having to change crush sleeve, which is there & I didnt remove. Something is pretty strange. It acts like the pinion race isn't in deep enough, when all I did was pull seal & yoke.

 

[Hogback Fabrication]

If the pinion race wasn't in deep enough, I think it would be the opposite problem.

When you get it to 1/4" away, what is stopping you? Stalling an impact? Are you trying to match the threads on the pinion and pinion nut?

 

[Bohemian]

If the pinion race wasn't in deep enough, I think it would be the opposite problem.

When you get it to 1/4" away, what is stopping you? Stalling an impact? Are you trying to match the threads on the pinion and pinion nut?

All I've done is remove the pinion nut with an impact, tap the yoke off with a plastic shot filled hammer, use a seal puller to remove old seal & tap in new seal with a big ass socket. I had no trouble with any of this.

Trouble begins when yoke will not go at or near the depth it was before I took it off.

I've only tried tightening the pinion nut with a 24" 1/2" drive rachet which should be sufficient to get it back to were it was, given I'm not crushing a new sleeve.

This am I pulled the yoke, nut & new seal out, took the bearing out, and shined a flashlight in to take a look. Either I have a solid spacer instead of a crush sleeve or its common to have one that spin's freely after being previously crushed. Not sure it's a big deal either way.

I also stuck the pinion yoke on without the bearing & seal and without the pinion nut on and it went to expected depth.

Light bulb... I looked at original seal I pulled and the new one I pulled out that I got from quad4x4 cause they're supposed to be better & low & behold the installed depth is more than the original.

So apparently when I installed new seal I must have drove in the pinion race further. Which I believe makes the crush sleeve hold the bearing out farther & subsequently the pinion yoke doesn't Go in to original depth.

Does this make sense?

What do you think my options are at this point?

Thanks in advance.

 

[AV8TER]

When you say pinion race I take it you are talking about the bearing cup. The outer race of a tapered bearing set. If so, you cant drive it in too far. It has a shoulder in its bore that it drives into. It gets driven in to the bottom of its bore when the cones are put in.

 

[Bohemian]

When you say pinion race I take it you are talking about the bearing cup. The outer race of a tapered bearing set. If so, you cant drive it in too far. It has a shoulder in its bore that it drives into. It gets driven in to the bottom of its bore when the cones are put in.

I'm open to other suggestions, but at the moment nothing else seems plausible.

Thanks in advance.

 

[diesel4me]

Picture is worth 1000 words...

The pinion bearings are installed from the driveshaft side with the taper facing out,and as already noted,the housing has a shoulder the "cup" is driven against--it cannot go "in" any further..

The pinion "might" have moved a bit and the spiral allowed it to drop further into the ring gear,but the ring gear is also tapered,so its unlikely it could drop "in" very far,not 1/4" ..if you could pull outwards on the pinion and it moves back up,then you found the problem..

I would suspect the seal is either different,has the "lip" in a different location (or was just plain wrong for the application),and it makes the yoke appear not to be going on all the way,but in fact IS,and just looks like it isn't..

 

[Bohemian]

All I've done is remove the pinion nut with an impact, tap the yoke off with a plastic shot filled hammer, use a seal puller to remove old seal & tap in new seal with a big ass socket. I had no trouble with any of this.

Trouble begins when yoke will not go at or near the depth it was before I took it off.

I've only tried tightening the pinion nut with a 24" 1/2" drive rachet which should be sufficient to get it back to were it was, given I'm not crushing a new sleeve.

This am I pulled the yoke, nut & new seal out, took the bearing out, and shined a flashlight in to take a look. Either I have a solid spacer instead of a crush sleeve or its common to have one that spin's freely after being previously crushed. Not sure it's a big deal either way.

I also stuck the pinion yoke on without the bearing & seal and without the pinion nut on and it went to expected depth.

Light bulb... I looked at original seal I pulled and the new one I pulled out that I got from quad4x4 cause they're supposed to be better & low & behold the installed depth is more than the original.

So apparently when I installed new seal I must have drove in the pinion race further. Which I believe makes the crush sleeve hold the bearing out farther & subsequently the pinion yoke doesn't Go in to original depth.

Does this make sense?

What do you think my options are at this point?

Thanks in advance.

Guess I need to repeat this and add IF hypothetically someone previously failed to fully install drive shaft side pinion race to bottom of it's bore it could account for the apparent movement I appear to be observing.

 

[diesel4me]

I doubt if the bearing cup wasn't bottomed out or in straight,that you'd have not had other issues with gear noise,backlash,pinion bearing failure, etc--its unlikely the bearing cup would not have been fully seated the first time the yoke was installed and torqued down to the proper spec,even if it hadn't been "driven home"when it was installed..and if it were not fully seated or crooked,the pinion would be free to go in and out some and really trash things in a hurry.....

 

[Bohemian]

I doubt if the bearing cup wasn't bottomed out or in straight,that you'd have not had other issues with gear noise,backlash,pinion bearing failure, etc--its unlikely the bearing cup would not have been fully seated the first time the yoke was installed and torqued down to the proper spec,even if it hadn't been "driven home"when it was installed..and if it were not fully seated or crooked,the pinion would be free to go in and out some and really trash things in a hurry.....

Makes sense, Although I still have something that appears related to the position of the pinion bearing & or race & or crush sleeve that is keeping the yoke from going on all the way, and since all I did is change seals and now I've eliminated the seal from the equation I'm left with it sure looks like something is wrong with the pinion bearing position.

I'm beating my head on the wall with this one, I don't want to have to tear down this entire rear end right now, just trying to fix the leak to get me through this hunting season & I'm boat anchoring the 10 bolts for 1 ton's.

Don't want to put much more time & money in crappy gm 10 bolts.

 

[diesel4me]

A long shot--maybe the crush sleeve didn't stay crushed,it was just "sprung" outward,and when you took off the pinion nut ,maybe it expanded out a little?...maybe just torquing the nut down will crush it back where it was ?...the fact you say the crush sleeve will spin on the pinion sounds suspicious...I would think once it crushed it would pinch itself tight to it..

 

[Bohemian]

A long shot--maybe the crush sleeve didn't stay crushed,it was just "sprung" outward,and when you took off the pinion nut ,maybe it expanded out a little?...maybe just torquing the nut down will crush it back where it was ?...the fact you say the crush sleeve will spin on the pinion sounds suspicious...I would think once it crushed it would pinch itself tight to it..

I was thinking the same thing, unless someone put a crush sleeve replacement kit in (solid spacer, shimmed to handle the pre-load).

I'll give it a go but I don't think I could crush a sleeve as much as its off.

If this don't work I think total tear down is my only option for piece of mind I'm not going to hamburger the ring & pinion.

 

[diesel4me]

It is tough to tighten the pinion nut enough with hand tools to get the crush sleeve to crush--unless its on a lift and you can use a pipe wrench to hold the yoke still while you reef on the pinion nut..

My friend replaces many pinion seals at his shop--he just blasts the nut on and off with his air impact gun,its a Snap-On beefy one that will put out 600 ft/lbs..

I always cringe when I watch him do that,and he does too,but he has been lucky so far,no one has come back with a lunched ring & pinion..he said he tried doing it manually and had a few customers return with noise complaints,and the yoke was loose,so he started using the air gun instead..