Rear wheel bearing? - 99 Suburban C2500

Pinger

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Update.
Measured axial play and it isn't as bad as I'd thought. It is 0.9mm.
Which is still over the permitted maximum of 0.75mm but only by 0.15mm. There is no discernable play on the other side (which to my mind implies worn clutch pack on one side rather than wear on the pinion cross shaft and/or C-clips).
The locking is working - I tested it with a wheel off the ground, forwards and reverse.

Given that the clutch plates are still suspect, and unless anyone thinks this is a very bad idea, I'm going to run with it for a bit and keep monitoring the play. If it is clutch wear it will surely gradually worsen in daily driving (as even without invoking the mechanical locking, during any kind of cornering where there is cornering force and a speed differential over the axle, the inner wheel is applying pressure to its clutch pack such that there is an element of anti-slip).

I will very likely be changing the clutches at some point so any info on that that anyone has to offer - please post here. Also, anyone running a G80 might consider - when they have the rear wheels off the deck - releasing the parking brake and checking for play...

Anyway, that's my plan - unless, like I said, anyone thinks it a bad one.
 

stutaeng

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GM manual talks of 'spreading axle casing'. Guy with his 8.0' just popped his out and back in without. What am I facing? And, as per Mr 8.0'', if I refit the bearings exactly as they were (including spacers/thrust washers), no problems with gear meshing etc?
There's a tool to "spread" the case so you can install the carrier side bearing shims. The carrier is "compressed" in the case to a required preload, just like the pinion bearing has preload. This helps to keep the bearings from chattering under load.

I made my own spreader (after a Google search) from some 5/8" threaded rod and tube steel I had laying around. Just had to weld some steel round stock pins. The differential has some holes for this.

Those shims you posted the link to seem like they are for establishing pinion gear depth. You add or remove shims of varying thicknesses to change where the pinion gear is relative to the ring gear gear.

I think you are fine...just keep on trukin'.:cool:

I'll try to remember to check on this axle for endplay one of these days.
 

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There's a tool to "spread" the case so you can install the carrier side bearing shims. The carrier is "compressed" in the case to a required preload, just like the pinion bearing has preload. This helps to keep the bearings from chattering under load.
In my case, as I'd be reinstalling exactly as it came out - would I absolutely need the spreader? (I've seen how-to vids and posts that talk of 'prying the diff out'. Never any mention of 'prying' it back in. Have I just answered my own question?)
I made my own spreader (after a Google search) from some 5/8" threaded rod and tube steel I had laying around. Just had to weld some steel round stock pins. The differential has some holes for this.
Cheers - something like that isn't beyond me.
Those shims you posted the link to seem like they are for establishing pinion gear depth. You add or remove shims of varying thicknesses to change where the pinion gear is relative to the ring gear gear.
Ah - that's what they are. I wondered (still wondering) if there's a G80 delete kit ie, replace the clutch plates with washers (or better still, rolling element thrust bearings) and be done with the clutch wear. I know though, sitting in snow with a wheel spinning I'd regret it.
I think you are fine...just keep on trukin'.:cool:
I'll keep an eye on the play - every couple of hundred miles. And with a case spreader built, be ready to jump on it if needs be.
I still have the MOT (annual safety inspection) test in August. If there's no more clutch wear, a new pinion cross shaft and C-clips might be enough to get the play to an acceptable level. If I can get Bert to test it (if his lift is working again), he understands USA vehicles and will see beyond 'worn wheel bearing' - which it obviously isn't.
I'll try to remember to check on this axle for endplay one of these days.
There might be surprise for a few people with G80s there!
 

stutaeng

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I believe some 14 bolt 9.5" have the little screw adjusters on the case for setting carrier bearing preload. Just like the 14 bolt 10.5".

You'll see it when you pop the diff. cover. In that case, you won't need a spreader. Just loosen the rings (count number of holes moved) and then install with same in reverse.

I don't know when the change was made though... maybe all of the GMT 400 9.5" are that way I don't know it?
 

Erik the Awful

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If you have that pinion shaft out, replace the lock bolt! They're one-use, and still they have a tendency to break when you pull them. From what I understand, both GM and Ford salisbury-style diffs use the same lock bolt. I haven't had a GM rear end apart yet to know for sure.

If you go to remove your pinion shaft lock bolt and it breaks, stop, put the diff back together as it is, and order the extraction kit. You can drive your truck a while longer until you can use the extractor. I drove my Mustang another year before I had time to tear into it again.
www.amazon.com/Deluxe-Differential-Pinion-Shaft-Extractor/dp/B007ZS4I3U/
 

Pinger

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I believe some 14 bolt 9.5" have the little screw adjusters on the case for setting carrier bearing preload. Just like the 14 bolt 10.5".

You'll see it when you pop the diff. cover. In that case, you won't need a spreader. Just loosen the rings (count number of holes moved) and then install with same in reverse.

I don't know when the change was made though... maybe all of the GMT 400 9.5" are that way I don't know it?
I saw that in a video where the guy was regearing a 9.5'' . Age of truck wasn't stated but a later than GMT400 for certain.
He had the whole shimming thing to do but I won't.
 

Pinger

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If you have that pinion shaft out, replace the lock bolt! They're one-use, and still they have a tendency to break when you pull them. From what I understand, both GM and Ford salisbury-style diffs use the same lock bolt. I haven't had a GM rear end apart yet to know for sure.

If you go to remove your pinion shaft lock bolt and it breaks, stop, put the diff back together as it is, and order the extraction kit. You can drive your truck a while longer until you can use the extractor. I drove my Mustang another year before I had time to tear into it again.
www.amazon.com/Deluxe-Differential-Pinion-Shaft-Extractor/dp/B007ZS4I3U/
I've book marked the page - cheers!
How does that thing work? It looks long enough to be worked from the hub end through the axle tube - but how with an axle shaft still in situ? I must be wrong.
 

Erik the Awful

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It's worked from the diff cover. The pinion shaft lock bolt is just below flush with the diff cover. The drillbit is long enough to flex. There's a bolt in the kit with a hole drilled in the middle of it (or middle-ish if you buy a cheap kit like mine). The drillbit flexes just enough to go through the hole in the bolt, right down the center(ish) of the broken off bit of the lock bolt. You then use the extractor to remove it. Mine was stuck, and bad - a worst case scenario. The extractor nearly broke off in it. The threads on the extractor are twisted, but it came free.
 

JWOK

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I saw that in the GM manual - whereas a 'how-to' on an 8.0'' G80 punched the pins out with punches.
Any more info on 'improvisation'? Does the C clamp have a forked end (to engage with a groove)?

Link to one of them? Can't find one specific to a 9.5'' one of appropriate age (1999).
Sorry for the delay and vagueness of my post. I should have clarified you can follow the process shown for 7.5, 8.0, 8.5, and 9.5 although I have not seen a breakdown specific to the 9.5 posted. I think the 7.5 only has clutches on one side, but the governor is similar. One difference between the 9.5 and many of the others is a roll pin pressed into the case parallel to the two governor shafts and I don't recall whether that had to be pressed out to get the clutches out.

Using punches likely won't work on the 9.5 as they do not all have governor shaft holes drilled through the ring gear side. I modified a heavy C-clamp years ago, rather than wait for the dedicated tool, just by grinding a shallow notch the width of the governor shaft in the fixed jaw opposite the screw. I think the jaw also had to be thinned down to fit inside the gap between the governor and bushing which is about 3/16". You can use a socket as a spacer under the clamp screw on the bushing side to give the bushing room to push out of the case. I have a 9.5 G80 sitting in my storage and was going to take some pics of the process, but I can't find the clamp. I will post pics if I manage to find it.

I have been into several gmt400 9.5s and they all had an adjustment nut at the passenger side carrier bearing and a shim on the ring gear side like @stutaeng stated so i don't know when that may have changed.
 
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