8.25 carrier wear

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Charlesvolare

Charlesvolare

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The spider gears in my 8.25 lost several teeth a few days ago. Upon disassembly, it looks like there was damage beforehand- the pin had some pretty extreme wear and the splined axle gears took some effort to pull out of the carrier. It took several hours of hammering to get the pin itself out.

I'm planning on replacing them with a lunchbox locker and was wondering how much the damaged carrier surfaces can affect the locker as far as wear and longevity? I know it isn't going to be anywhere near ideal, but there shouldn't be very much movement with this type of locker.

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Look on ebay for a pre 96 Sure Grip out of a Jeep 8.25. They are listed on there all the time. 97 and later have different splined axles. 29
 
How many miles does it have on it, what is it in, and what kind of power are you hitting it with? I've seen some pretty hard wear on some truck 8-1/4's, but that one has really been put through it. That carrier is trashed to the same extent as the spiders and pin and not salvageable. Not only that, but you've got a lot of metal that's washed through everything else and probably have more damage than whats pictured. I'm certain the carrier bearings have got some damage, and I would be really surprised if you don't have some vertical and horizontal slop in the pinion once you get everything washed out.
 
If you had to beat the pin out, the case is probably toast; looks like it spent a lot of time being peg-pegged, doing one wheel brakie-burnouts.
I'm with Garrett;
I would trash everything in there, with the possible exception of the C&P, if they are 3.55s or better.

But this time put a SG in it on Day-1,lol.
 
Garrett Ellison said:
How many miles does it have on it, what is it in, and what kind of power are you hitting it with? I've seen some pretty hard wear on some truck 8-1/4's, but that one has really been put through it. That carrier is trashed to the same extent as the spiders and pin and not salvageable. Not only that, but you've got a lot of metal that's washed through everything else and probably have more damage than whats pictured. I'm certain the carrier bearings have got some damage, and I would be really surprised if you don't have some vertical and horizontal slop in the pinion once you get everything washed out.
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I went through it a couple of years ago, put in a set of 3.55's (from a Jeep) and replaced all of the bearings. It's behind a hot 360/904, probably 350hp. It's been abused, a few 2nd and 3rd gear one wheel burnouts over the last few years.

I got everything cleaned out this morning, the ring and pinion look good and the bearings still feel tight. No slop from what I can tell but I might throw on the dial indicator. I may have an extra set of carrier bearings from when I rebuilt it but I'll have to check on that.

I was wanting to go with a suregrip, which would require a whole different carrier, and then eventually upgrade the rear end to a 8.75 or an 8.8 or something bigger. So I'm not looking to keep this one going for 40+ more years but I still want it to still be pretty decent for a few years at least. Throwing in the lunchbox locker is quickest way to get it back on the road and I was hoping to flush everything out good enough for the bearings to last. Just wasn't expecting all the wear on the carrier.
 
Went ahead and pulled the carrier. Bearings look good to me, nothing besides some discoloration. Is it worth it to pull the pinion?
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I ended up haveing a new crush sleeve and carrier bearings, AutoZone had a pinion seal. Made sure every was clean and nothing was in the pinion bearing cages and set it all back up, resetting the preload and everything.

So should the carrier be okay to throw a locker on with the wear? It shouldn't have anything rotating like the spider gears did so I feel like it has a bit more tolerance with that sort of stuff
 
SGBARRACUDA said:
Sounds like you've already made up your mind?
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I mean it sorta makes sense to me with it having way less rotating parts than spider gears or a posi but it's not together yet, just double checking and seeing what everyone else's opinions were.
 
What brand of lunchbox locker are you looking at? It's been a while since I've studied on those, but I think your side clearance for the couplers is going to be out of spec. And then the whole business of the cross shaft holding the locker together... How egg shaped do you think those holes for the cross pin are. Honestly, I wouldn't even try to run a mini spool (if it were available) with that.
 
And, the side couplers that butt up against the diff carrier still rotate the same as differential when you make a turn, so there is still quite a bit of rotation going on against the housing. I don't see paying the cost for the locker just to put it in somewhere that's going to grind on it like your case. Add excess lateral slop into the equation and factor in that the amount of force of that is being transmitted through it. I can't possibly see it ending well. A little refreshment on the operational dynamics.
What Is A Lunchbox Locker And How Does It Work?
 
Charlesvolare said:
It's been abused, a few 2nd and 3rd gear one wheel burnouts over the last few years.
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That right there is the culprit. No one ever thinks about just how fast ONE SIDE spins during a burnout. They are not designed for that type speed. That's what causes them to over heat, cook the gear oil and start galling the small pinion gears to the cross shaft. I agree 100% with Garrett. No way would I use anything out of that housing. I'd start all over fresh with everything, right down to the bearings and races.
 
Garrett Ellison said:
How egg shaped do you think those holes for the cross pin are.
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That's it right there.
If the cross-pinholes are egged out, the crosspin retaining bolt or roll-pin, as the case may be, is gonna come under a lot of pressure. When it fails, the pin is gonna want get the heck outta Dodge,lol. If there is room for it to get by the ring gear, then it is heading for the back cover, where it will probably not make it all the way thru. So stuck there as it is, it will lock up your entire rear end and skid the tires. If this happens at 20/30 mph, you just get a heck of a scare. If it happens at 60, the back end is gonna spin around in a heartbeat, and it will be impossible to steer the car. At 60 mph you are traveling at 88 feet per second, with no steering and the brakes do not do much when careening sideways, so basically you have become an unguided missile.
Pray it doesn't happen in traffic.
It doesn't matter if the pin doesn't make it to the cover, no matter where it stops, the result will be the same.
If you tack-weld it in, the slop where the side gears formerly resided will eventually break the tacks. So if you weld it in, make sure it never comes outta there. Ohhhhhhhhhh, wait........... lol. You better put new wheel bearings and seals in, now, followed by the C-clips and then weld in the cross-pin, cuz you won't get another chance.
 
And not to mention, your axle tubes are full of fine metal shavings, too. So as AJ said, wheel bearings are highly suspect as well. And especially with a C clip axle, I also get concerned with how much heat got transferred into the axle shafts when the diff was grinding itself into mill shavings. It doesn't take a whole lot of excess heat to foul up the temper in an axle shaft. I seen someone learn the hard way once that the guts have to come out of an axle when welding new spring perches back on. It definitely wasn't pretty.
 
Charlesvolare said:
Bearings are still looking good though.
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That's gonna be your little secret. And it's WRONG. Imagine all the tiny metal particles that made their way into and through those bearings and all the rest of them. If you don't start all over with a BARE housing and clean it operating room clean, you better be prepared to do this all over. Again.
 
RustyRatRod said:
That's gonna be your little secret. And it's WRONG. Imagine all the tiny metal particles that made their way into and through those bearings and all the rest of them. If you don't start all over with a BARE housing and clean it operating room clean, you better be prepared to do this all over. Again.
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I know it's not the perfect way of doing it, but like I said I'm planning on replacing the whole rear end within the next year or two, so I'm just looking to get it back together and driving.

AJ/FormS said:
That's it right there.
If the cross-pinholes are egged out, the crosspin retaining bolt or roll-pin, as the case may be, is gonna come under a lot of pressure. When it fails, the pin is gonna want get the heck outta Dodge,lol. If there is room for it to get by the ring gear, then it is heading for the back cover, where it will probably not make it all the way thru. So stuck there as it is, it will lock up your entire rear end and skid the tires. If this happens at 20/30 mph, you just get a heck of a scare. If it happens at 60, the back end is gonna spin around in a heartbeat, and it will be impossible to steer the car. At 60 mph you are traveling at 88 feet per second, with no steering and the brakes do not do much when careening sideways, so basically you have become an unguided missile.
Pray it doesn't happen in traffic.
It doesn't matter if the pin doesn't make it to the cover, no matter where it stops, the result will be the same.
If you tack-weld it in, the slop where the side gears formerly resided will eventually break the tacks. So if you weld it in, make sure it never comes outta there. Ohhhhhhhhhh, wait........... lol. You better put new wheel bearings and seals in, now, followed by the C-clips and then weld in the cross-pin, cuz you won't get another chance.
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That's a good point, I had a 7.25 that lost some teeth on the ring gear and locked everything up. It was on the on ramp so it was fairly low speed. I'm about to check if the local pull a part is open today and if it is go see if I can get a new carrier. I don't have anything else to do in this quarantine lol

As far as getting the housing clean, I still have a case of brake clean.
 
You’ll have to let us know how it turns out. The pinion and axle bearings are going to be the biggest crapshoot. They could be good for 100 miles or have 100,000 miles left on them.
 
Garrett Ellison said:
You’ll have to let us know how it turns out. The pinion and axle bearings are going to be the biggest crapshoot. They could be good for 100 miles or have 100,000 miles.
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Will do! I took a lot of time making sure the pinion bearings were as clean as possible yesterday, I'll quadruple check everything before final assembly.
 
AS to bearings;
This is how we used to pass/fail used bearings;
the visual check, and the audible check, and the manual test.
>As to the visual; no pits, no flaking, no discoloration, and no unidentifiable markings
>As to the audible; this is more for ball bearings, but, the quieter they are when dry spun, the better. keep one new bearing, in a bag, on the bench as your standard; when in doubt, haul it out and give it a whirl. I don't see how you can apply this to a tapered bearing, but that's what we did.
> as to the manual test;
for tapered we fitted the cones to new races, put them on the bench, pressed down hard and rotated them, looking for an excuse to throw then away, I mean we had truckloads of bearings. Then we did the same to the races with new cones.
For ball-bearings, we loaded the sideways, looking for roughness, andtwisted them to "measure " side play.
 
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