Replacing pinion bearings in a rear 10B... 9.25.07 - bearings look good???

[jonrpick]

I just got to thinking...would it be easier or cheaper to replace the bad pinion bearing(s) in my 10-bolt rather than replacing the whole axle with a used one?

I'm starting to get a little anxious about getting the K5 back on the road and selling off my current DD. I got laid off and I'll drop off payroll at the end of September. I want this done ASAP.

I'm still going to get the 1-ton running gear, but it'll be incomplete to start with--it'll take time and money to prep them for the swap, plus any other parts I may need to do the swap.

If I try to just replace the pinion bearings and seal, will I need to complete setup up the rear again with new shims to get the proper pinion depth or what?

Thanks,

 

[4X4HIGH]

You will need to set pinion depth to start with which requires special tools to do it correctly. You would be money ahead to swap the 14ff in now and deal with gear issues later if they aren't what you want.

 

[jonrpick]

You will need to set pinion depth to start with which requires special tools to do it correctly. You would be money ahead to swap the 14ff in now and deal with gear issues later if they aren't what you want.

I was afraid someone might say that.

Oh well...

 

[sandracer799]

You will need to set pinion depth to start with which requires special tools to do it correctly. You would be money ahead to swap the 14ff in now and deal with gear issues later if they aren't what you want.

Or you could use the same amount of shims that are in there now and use that as a baseline when putting the new bearings on...

 

[jonrpick]

Or you could use the same amount of shims that are in there now and use that as a baseline when putting the new bearings on...

Well, I've never done anything with an axle before, so I'd be real hesitant to try now. It's important that it's right.

 

[user]

I disagree

Just replacing the bearing and the oil seal will not require funky measurement or elaborate set-up procedures. The only difference is that you'll need a torque wrench that measures in inch-pounds in order to set the pinion nut to the correct tightness. It takes a different number of inch pounds for new bearings than for used. Oh, and btw, you'll need a new crush-sleeve, too, which you can get at any GM dealer, I think; probably any Carquest, Autozone, AdvanceAuto, etc etc can get 'em and may have them in stock. Make sure you read up on how to do it. Send me an email at clist [at] virginialegaldefense [dot] com and I'll send you pictures of some tools I made (inexpensively) and more information to help with that particular job.

 

[daleearnhardt01]

Just replacing the bearing and the oil seal will not require funky measurement or elaborate set-up procedures. The only difference is that you'll need a torque wrench that measures in inch-pounds in order to set the pinion nut to the correct tightness. It takes a different number of inch pounds for new bearings than for used. Oh, and btw, you'll need a new crush-sleeve, too, which you can get at any GM dealer, I think; probably any Carquest, Autozone, AdvanceAuto, etc etc can get 'em and may have them in stock. Make sure you read up on how to do it. Send me an email at clist [at] virginialegaldefense [dot] com and I'll send you pictures of some tools I made (inexpensively) and more information to help with that particular job.

I agree, no need for a pinion depth tool... Get a friend to help or read up on how to do it and go for it. It shouldnt be anything to be afraid of.

 

[jonrpick]

I agree, no need for a pinion depth tool... Get a friend to help or read up on how to do it and go for it. It shouldnt be anything to be afraid of.

Ok, I think I'm going to try it. Worse case scenario, I'll end up replacing the 10-bolt with a used one as planned.

Any words of advice? As of right now, I know I'll need a new bearing(s) (how pinion bearings are there???), a crush sleeve, a torque wrench capable of measuring lb/inches... what else?
.......
I just called the local 4x4 supply shop...they have a master install kit that includes:

Pinion nut, pinion seal, crush sleeve, inner and outer pinion bearings, carrier bearings, ring gear bolts, complete shim kit, gear marking compound, and a cover gasket... as seen here:

http://www.4wheelparts.com/PPT2223T5092.aspx

The dude on the phone says that the backlash may change when I do this, requiring the gears to be set up again. I'm *really* wanting to avoid that. Any advice???

 

[user]

The dude on the phone says that the backlash may change when I do this, requiring the gears to be set up again. I'm *really* wanting to avoid that. Any advice???
=====

that's not true - backlash is determined by the side to side relationship of the ring gear and carrier to the pinion. That's set by the shims on either side of the carrier (adjacent to the inner axle bearings). As long as you keep the shims exactly as they were before removing the carrier, the backlash won't change.

I suspect that the dude really meant that the pinion depth could change, and that's a slight possibility. If you get the pinion out and determine to replace both the inner and outer bearings, and those bearings aren't exactly the same thickness as the ones you had in there before, then you'll need to adjust the shims that go on the pinion shaft to determine the depth.

The hard thing about differentials is that the ultimate relationship expressed by the wear pattern is the result of a confluence of vectors in three dimensions. Most people can't visualize that kind of data. But it's easy to keep straight if you only mess with one variable (e.g., pinion depth) at a time.

Here's my suggestion on managing pinion depth. Measure the thickness of the old parts and compare with the appropriate new parts. You'll need a caliper that measures in thousandths of an inch. You'll need one, too, to measure the thickness of the shims. It's the inner bearing and the shims that are underneath of it that determine the pinion depth. So what you need to do is to make sure the new setup is the same as the old setup, within a thousandth or two.

 

[user]

btw, you can get exactly the parts you need, without buying the "master install kit". For one thing the bearings they put in those kits are crap. Depending on how often you want to have to redo this job, you may want to get some decent bearings (e.g., Timken). Brand X from Autozone, Carquest, or Advance Auto will not be any good either. It's not just materials, it's also failure to adhere to adequate tolerances. Most people don't actually use gaskets anymore (I'm the only person I know who does so, but that's because I like to be able to get in and out of the differential a lot), and you can get a tube of black silicone gasket material that will work really well. The shims may not be what you need, and you definitely don't need either the side bearings or side bearing shims if you're not having problems with those (and especially if you don't want to mess with backlash adjustments). You're best off determining on the basis of measurements what shims you need specifically and going to get an appropriate set (along with a new crush sleeve) from the GM dealer. You probably don't need any shims at all, since you're not actually replacing gears. Prussian blue marking compound is available all over the place.

 

[jonrpick]

The dude on the phone says that the backlash may change when I do this, requiring the gears to be set up again. I'm *really* wanting to avoid that. Any advice???
=====

that's not true - backlash is determined by the side to side relationship of the ring gear and carrier to the pinion. That's set by the shims on either side of the carrier (adjacent to the inner axle bearings). As long as you keep the shims exactly as they were before removing the carrier, the backlash won't change.

I suspect that the dude really meant that the pinion depth could change, and that's a slight possibility. If you get the pinion out and determine to replace both the inner and outer bearings, and those bearings aren't exactly the same thickness as the ones you had in there before, then you'll need to adjust the shims that go on the pinion shaft to determine the depth.

The hard thing about differentials is that the ultimate relationship expressed by the wear pattern is the result of a confluence of vectors in three dimensions. Most people can't visualize that kind of data. But it's easy to keep straight if you only mess with one variable (e.g., pinion depth) at a time.

Here's my suggestion on managing pinion depth. Measure the thickness of the old parts and compare with the appropriate new parts. You'll need a caliper that measures in thousandths of an inch. You'll need one, too, to measure the thickness of the shims. It's the inner bearing and the shims that are underneath of it that determine the pinion depth. So what you need to do is to make sure the new setup is the same as the old setup, within a thousandth or two.

It's funny...I've been visualizing the whole thing better the more I thought about it. And actually I'd kinda figured it out before you posted this.

My plan was to pull the pinion and, as you said, get a *good* set of digital calipers and measure the old parts. If the inner bearing is "thicker" then that could be taken care of by using a different shim behind it.

It would be *awfully* nice if it was only the outer pinion bearing.

 

[iwaxmyjimmy]

pull the carrier/ring gear, take off the pinion nut, knock off the yoke, then pop the pinion through, press off the bearing, press on the new one put it back together. You can reuse the crush sleeve just dont "crush it" anymore. You wont need to check ne backlash or pinion depth if you use GM parts. You dont need an in-lb torque wrench to get the pinion nut to "spec". count the treads and mark it with white out. But plz use loc-tite and "stake" the nut once you have it back on.

 

[jonrpick]

btw, you can get exactly the parts you need, without buying the "master install kit". For one thing the bearings they put in those kits are crap. Depending on how often you want to have to redo this job, you may want to get some decent bearings (e.g., Timken). Brand X from Autozone, Carquest, or Advance Auto will not be any good either. It's not just materials, it's also failure to adhere to adequate tolerances. Most people don't actually use gaskets anymore (I'm the only person I know who does so, but that's because I like to be able to get in and out of the differential a lot), and you can get a tube of black silicone gasket material that will work really well. The shims may not be what you need, and you definitely don't need either the side bearings or side bearing shims if you're not having problems with those (and especially if you don't want to mess with backlash adjustments). You're best off determining on the basis of measurements what shims you need specifically and going to get an appropriate set (along with a new crush sleeve) from the GM dealer. You probably don't need any shims at all, since you're not actually replacing gears. Prussian blue marking compound is available all over the place.

Well...too late on the master install kit. I already got it.

The dude was trying to talk me into replacing the carrier bearings as well. I really don't want to. At that point, it'd be having to set up the whole thing.

 

[iwaxmyjimmy]

take it back, or ebay it. The more parts you replace the more its gonna be outta wack. Also use GM parts b/c they are built the same.

 

[jonrpick]

take it back, or ebay it. The more parts you replace the more its gonna be outta wack. Also use GM parts b/c they are built the same.

well, I don't know that it has stock parts now. I had it rebuilt/replaced... not sure which. I don't recall if the guy swapped in another rebuilt unit or rebuild mine. But I don't think it's the original axle. As I recall, it looked different when I got it back. So it could be aftermarket parts.

 

[jonrpick]

By the way... Once I have it apart, will I be able to tell which of the pinion bearings is bad? I think the outer is more likely, as it would've been starved for oil more so than the inner one.

 

[iwaxmyjimmy]

Is there alot of play in the yoke? side to side? back and forth? If its just noisey there will be alot of pitting. Call the guy up and ask him what bearings he used. And how long ago was it?? If it was less than 20K miles he alt to fix that for free.

 

[daleearnhardt01]

pull the carrier/ring gear, take off the pinion nut, knock off the yoke, then pop the pinion through, press off the bearing, press on the new one put it back together. You can reuse the crush sleeve just dont "crush it" anymore. You wont need to check ne backlash or pinion depth if you use GM parts. You dont need an in-lb torque wrench to get the pinion nut to "spec". count the treads and mark it with white out. But plz use loc-tite and "stake" the nut once you have it back on.

You are crazy to think that if you use GM parts that you dont need to check pinion depth/pattern after you do this job....

Do the job right, not half-assed.

 

[iwaxmyjimmy]

Thats how I do them and I dont have come backs at my shop.

 

[daleearnhardt01]

Thats how I do them and I dont have come backs at my shop.

Funny how the GM service manual clearly states that those steps must be done...

You do them however you like, I dont care but it is half-assed.