Rear axle, wheel bearing and much more...

Anything related to the stock drivetrain, engine, transmission, axles, wheels...

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JaVeRo
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Rear axle, wheel bearing and much more...

Post by JaVeRo »

I knew my wife's blazer had a wheel bearing going out but I had to get her '01 crewcab going first so she would have something to drive on the mail route. Put new Tom's Axles and wheel bearings and seals in the crewcab and started on the blazer.

The right wheel was the one that was bad. I planned on putting a repair bearing (offset bearing) in it with the better of the two axles that I took out of the crewcab and order two more Tom's Axles with new bearings to fix it right later when the parts came in. The wheel bearing was worse than I thought. Metal shavings everywhere. I pulled the differential so I could flush out the shavings and found this.
Image

I figure the shavings got into the carrier bearing and started eating on it also. The left side bearing was fine. My thinking was that if I pulled the differential and the bearings were ok and I didn't mix up the shims, then I could flush out the axle tubes and put it right back like it was and every would be fine. I should have checked the backlash first but didn't have a dial indicator. I will buy one this week.

My plan now, since I have to replace the bearings, get a detroit truetrac differential with new bearings. Pull the driveshaft and spin the pinion gear hoping that those bearings are still good. Put my ring gear on the truetrac and install, shimming it to get the spec on backlash. I sure wish I knew what the backlash was before I started. Put new Toms Axles and wheel bearings in it and hope it works.

Honestly I am in over my head. Someone tell me all the flaws in my logic.

James
2001 S10 Crew (wife's mail truck)
2002 S10 Crew, 2003 S10 Blazer
2006 K2500 5 speed
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HenryJ
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Re: Rear axle, wheel bearing and much more...

Post by HenryJ »

I would not spend money on a new or used locking carrier for the stock differential. The stock differential is just too squishy and flexy. Personally, this would be a good time to upgrade to the ZR2 rear axle. You will be money ahead in the long run.
Right now you are trying to upgrade, and repair. The money you spend to patch this one together may or may not work. If you do it right replacing all the bearings , axles and carrier...you will have spent as much or more than swapping in a ZR2 axle.
I was where you are with my stock rear axle when I found the pinion shim squished out. Best thing I ever did was to install the ZR2 rear axle.

Now, all that said ... what gear ratio do you have? If it is the 3.73 ratio, you are all set. If it is the 3.42 you have to make another decision.

3.42 means you would need to change the gearing on the front to match the ZR2 axle. That might change my mind. In that case I might patch the rear together with either the stock carrier , or a cheap open carrier. I would not extra spend money to upgrade the stock diff , carrier, or axles. If you gotta make it go, put the needed bearings in to get it going as is. Save your upgrade $$ for a ZR2 swap.

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JaVeRo
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Re: Rear axle, wheel bearing and much more...

Post by JaVeRo »

I have a zr2 axle that I bought several years ago to put in the crewcab. This blazer is 3.42 gears, that's the reason for trying to rebuild it. The truetrac is only about $450 and it's my wife's money. This differential is open, not a G80, I could just put new bearings on it but I would like to try the truetrac.

James
2001 S10 Crew (wife's mail truck)
2002 S10 Crew, 2003 S10 Blazer
2006 K2500 5 speed
JaVeRo
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Re: Rear axle, wheel bearing and much more...

Post by JaVeRo »

One problem with putting the ZR2 axle on the blazer is the bump stop being different.
Image
Another is the Blazer has a swaybar. It just clamps to the axle with a Ubolt but if the housing is a different diameter then that would have to be modified. Nothing that could not be overcome but I was really wanting to put the ZR2 axle in the newest crewcab. It hasn't been on the mailroute yet.

What would be the chances of finding a Blazer ZR2 axle?

James
2001 S10 Crew (wife's mail truck)
2002 S10 Crew, 2003 S10 Blazer
2006 K2500 5 speed
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Re: Rear axle, wheel bearing and much more...

Post by HenryJ »

I don't think the Blazer ZR2 axle will help. I think you will find it different than your Blazer too. It may not have those bumpstop pads. I just don't remember seeing them.

I think you might be able to pick up a good used G80 diff for much less than the TrueTrak. I am not sure how I would feel about an extra $450 just to "try a truetrak.
I would be very tempted to just get new bearings , clean it all up and put the open carrier back in. It is your best chance for a fit without setting the differential all up again. Swapping to the truetrak is going to mean finding the right shims. That means a "set up" set of bearings , gear marking compound and a dial indicator. Lots of time and patience.
From what you have described so far that may be beyond your skill set? I hate to see you with it taking out your ring and pinion , then spending another $1k to get it fixed again :(

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Re: Rear axle, wheel bearing and much more...

Post by _STUCKY »

I agree with Brule. Fix what's broke for the least amount of money. It's a pretty small axle to be dumping money into. For the cost of the true track you could find a zr2 and get both the front diff and rear axle. I wouldn't sweat the bumpstop bracket or sway bar, both could be made to work.
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Re: Rear axle, wheel bearing and much more...

Post by ApproachMedium »

Blazer axles are a dime a dozen. I think the local yards here (who are a bit pricey compared to the rest of the country) let them go for about 200. FWIW for a blazer just swap a used axle in. Something you could do with a friend in the back yard in an hour.
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JaVeRo
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Re: Rear axle, wheel bearing and much more...

Post by JaVeRo »

I ended up just putting new bearings on the differential and putting it back in with the same shims in the same locations. I know it's not a long term fix. The pinion shaft did not have any play/slack/roughness in it but the rotational torque was zero. Any preload that was there is gone.

Rotational torque after reinstalling the carrier was 12 inch pounds. It should have been a little more with new bearings according to the book. I tried checking the backlash but with zero resistance on the pinion, that was hard to measure. Along with the fact that it was almost midnight, I gave up. I have thought of a dozen ways of holding the pinion since then but it's too late for that. Just feeling the slack by turning the pinion, any gap was very slight.

My next project for this truck is to replace the front a rear differentials with parts from a ZR2. I might as well get as many miles as I can out of this axle first.

James
2001 S10 Crew (wife's mail truck)
2002 S10 Crew, 2003 S10 Blazer
2006 K2500 5 speed