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  #16 (permalink)  
Old 05-10-2012, 08:15 PM
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The truck rearend you have is not an 8.5", it is a 12 bolt 8.75", and a very good rearend for what you want to use it for. That rear should be a 5x5" pattern, not a 5x5.5" pattern. The rearend on the right appears to be the 1970 8.2", and not the '71 -'81 8.5" rear. The 8.5" rears have squared corners cast into the housing that hang below the rear and identify them as the 8.5" rears.
They look like this, my '71 Camaro 8.5":

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Old 05-10-2012, 08:43 PM
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indeed, it's a 5x5 pattern.

so it's a good one, great, I'm gonna use this one

do you know if I can weld the ears for the 4 link to this pumpkin? if the axle tubes can be welded to the pumpkin, I guess some 1018 steel brackets can be welded to it, so I can use it in my G body ?

what kind of weld? ER70ES MIG, 7018 stick?
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Old 05-10-2012, 08:47 PM
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I didn't noticed that the camaro's ears were not squared, I just saw them and asumed it is a 8.5, you are rigth, it should be a 8.2. the pinion has 30 splines, do this tells something?
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Old 05-10-2012, 11:43 PM
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Quote:
Originally Posted by Augusto
I didn't noticed that the camaro's ears were not squared, I just saw them and asumed it is a 8.5, you are rigth, it should be a 8.2. the pinion has 30 splines, do this tells something?
I'm no expert, but the only 10-bolt stock pinion w/30 splines that I'm aware of is the corporate 10-bolt 8.5".
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Old 05-11-2012, 08:34 AM
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Quote:
Originally Posted by cobalt327
I'm no expert, but the only 10-bolt stock pinion w/30 splines that I'm aware of is the corporate 10-bolt 8.5".
If it's a 30 spline, then it should be a 8.5", as the only other 30 spline was the later Yukon 8.6". They did make upgraded carriers and axles for the 8.2" that made it a 30 spline, but they were aftermarket.
Make sure you've counted correctly, and it's not a 28 spline.
I am not a qualified welder, so I can't tell you what rod or wire to use to weld to the housing. I have seen people weld to cast steel housings, but not sure what they used.
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Old 05-11-2012, 08:27 PM
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I can take it apart and measure the ring diameter, what diameter is it? the outermost diameter of the ring or the inner diameter that mates to the carrier?

I'm pretty sure it is a 30 spline, checked several times, and had been looking for a yoke for it with no luck for months.

so it is possible to weld ears to the housing, good, I need to find out what rod and if 1018 steel can be welded to it.
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Old 05-11-2012, 09:32 PM
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Quote:
Originally Posted by Augusto
I can take it apart and measure the ring diameter, what diameter is it? the outermost diameter of the ring or the inner diameter that mates to the carrier?
Outermost diameter.

Also an 8.5" 10-bolt corporate ring gear is held on by 7/16-20 left hand threads, having a 3/4" hex head on the bolts. The 8.2" rear has 9/16" hex head bolts and is right hand threaded. The thread size of the 8.2 ring gear is 3/8-24.
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Old 05-11-2012, 10:04 PM
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ok, I'll get my hands oily this weekend, thanks.
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Old 05-16-2012, 11:14 AM
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Both the 7.5 and the 8.5" GM rear ends are fine once the stock differential is replaced with either a Auburn or a Eatons posi.

And the ring and pinion is set up correctly for pinion depth and gear back lash.
And crush sleeve compression.

Using a spool on either of these axles almost guarantee a failure if used on pavement.
99% of rear end problems are directly related to poor install method.

Do not use the stock differential even if its free. Do no use a spool. EVER.

If you don;t know how to properly install the ring and pinion find someone who does know how to do it right and pay them.

They will take all kinds of power. Any rear end will fail if you abuse it.
Including Ford 9".
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