rear axle questions

eran tomer

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Going from 9.5" ring gear axle to 10.5" ring gear axle, you'd not only need to verify the U-joint, you'll also have to verify how much farther the yoke is from the axle centerline.

When changing an 8.5 to a 9.5, the 9.5 yoke is about 3/8" farther from the axle centerline. Ideally, the driveshaft should be shortened ~3/8", but no-one does--they just cram it farther into the tailshaft housing.

And that works. That's what I did, years ago.

But I don't know how much bigger the 10.5 housing is from the 9.5 housing. I have a suspicion that it's enough bigger to require shortening the driveshaft. This is only a suspicion. Supposed to have thunderstorms starting any minute, and lasting all day tomorrow; and I'll be gone for the weekend. Remind me, and I'll take a measurement or two when I come back
I remind you…
 

Schurkey

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Been under both trucks twice each. Took photos, but they came out blurry.

Best I can tell, the two axles are closer than I expected in pinion distance. The 9.5 seems to have a longer housing than the 10.5, which surprised me. The 9.5 seems longer by an inch, maybe an inch and a quarter. I'm getting 12.25" for the 10.5; and 13.25"--13.5" for the 9.5.

I'd have to drop the driveshafts on them, and put a square in the driveshaft yoke saddles to get any closer

I'm thinking it's very likely you'd need to lengthen/shorten the driveshaft if converting from one axle to the other.
 

eran tomer

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Been under both trucks twice each. Took photos, but they came out blurry.

Best I can tell, the two axles are closer than I expected in pinion distance. The 9.5 seems to have a longer housing than the 10.5, which surprised me. The 9.5 seems longer by an inch, maybe an inch and a quarter. I'm getting 12.25" for the 10.5; and 13.25"--13.5" for the 9.5.

I'd have to drop the driveshafts on them, and put a square in the driveshaft yoke saddles to get any closer

I'm thinking it's very likely you'd need to lengthen/shorten the driveshaft if converting from one axle to the other.
thanks for the effort. from the photos i've seen the 9.5 housing does seem longer, but the 10.5's yoke has some kind of an external bearing, so they could be even.
the u-joints looked the same?

i've read that for u-joints there are "1310", "1450" etc. are these universal measures or what?
 

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The 10.5 has a third pinion bearing, but it's a little one by the ring gear end. That overhung bearing got eliminated in later model years, but I've forgotten just when. The external difference is that the pinion is carried in a removable section, attached to the main housing via bolts 'n' shims, where the smaller axles have a one-piece housing.
 

eran tomer

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i've been sarting to wonder whether the axle housings have various yoke angles for the various platforms (ie suburban, short cabin, long cabin etc.) to match the different wheel base lengths, not only the full float but in general, and if they do then whether you must get the axle from the same model you have, otherwise the joints will wear prematurely.:rolleyes:
 

stutaeng

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i've been sarting to wonder whether the axle housings have various yoke angles for the various platforms (ie suburban, short cabin, long cabin etc.) to match the different wheel base lengths, not only the full float but in general, and if they do then whether you must get the axle from the same model you have, otherwise the joints will wear prematurely.:rolleyes:
Highly doubtful about different yokes. It's GM, they use the same part for a wide range of vehicles, as much as possible.

What are you trying to figure out again? I've got a 14 bolt 10.5" and a hybrid 14bolt/12 bolt 9.5" in my garage. They are from later trucks, but I bet the housings are still the same...
 

stutaeng

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Yeah, maybe not a good approach to measure different year housings then. There was also a switch from GM in-house manufacturing to AAM at some point...
each axle size has maybe half a dozen different part numbers for the housings.


what's that?

The K2XX V8 1500 trucks got switched to a hybrid 9.5" or 9.76" axle with 6 lugs. It seems some parts got carried over from the "old" 14 bolt 9.5", but got some different parts like... I'm not sure what yet, are new. The diff cover has 12 bolt.:rolleyes:
 

eran tomer

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i got me a fullfloater from the junk yard, and the vent nipple is broken. what's the best fix for that? the parts diagram shows that the plastic vent valve is stuck right into the axle but it doesn't make sense.
 

Supercharged111

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Yeah, maybe not a good approach to measure different year housings then. There was also a switch from GM in-house manufacturing to AAM at some point...


The K2XX V8 1500 trucks got switched to a hybrid 9.5" or 9.76" axle with 6 lugs. It seems some parts got carried over from the "old" 14 bolt 9.5", but got some different parts like... I'm not sure what yet, are new. The diff cover has 12 bolt.:rolleyes:

Wasn't it 9.5" ring gear but with 8.5" sized externals? Like wimpier axle shafts and outer bearings?
 
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