The Cheap Route: Putting a 7.625 in a 7.5 housing

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64nailhead

Goat Herder
Dec 1, 2014
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If the 'Auburn mini locker' is an actual mini spool, then it'll suck on the street unless you have narrow, slippery tires - extremely hoppy and bangy when turning.

The cheap way out is to use S10 2wd axles with a 1/4" spacer added to the backing plates to accommodate the 1/4" S10 longer axles. Then use a stock Torsen diff from a 98-02 Camaro/Firebird. 3.42's without OD and 3.73's with it. Don't let anyone kid you or themselves into what a well built 7.5/7625 can take - we put over 500HP through one built as described above for a full summer before we put in an 8.5 (8.6). It sits in the basement as a spare in case we blow up the 8.5 lol.
 
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jetsetw31

G-Body Guru
Sep 9, 2010
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Petersburg, VA
If the 'Auburn mini locker' is an actual mini spool, then it'll suck on the street unless you have narrow, slippery tires - extremely hoppy and bangy when turning.

The cheap way out is to use S10 2wd axles with a 1/4" spacer added to the backing plates to accommodate the 1/4" S10 longer axles. Then use a stock Torsen diff from a 98-02 Camaro/Firebird. 3.42's without OD and 3.73's with it. Don't let anyone kid you or themselves into what a well built 7.5/7625 can take - we put over 500HP through one built as described above for a full summer before we put in an 8.5 (8.6). It sits in the basement as a spare in case we blow up the 8.5 lol.
It's actually a locker. The Max Lock Locker is Auburns version of the Powertrax Lock Right Locker. I'm well aware of the limits of these housings. The gears can handle 500hp but the housing flex is the killer. If i get bit by the track bug this season, I'll green light a girdle for this rear. A 8.5 build is in my future plans.
DSC_1045a.jpg
 
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jetsetw31

G-Body Guru
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The g bodies are thinner/ lighter cause the extra tall flange that adds alot of extra strength . Both are plenty strong in there own respective design.
Your absolutely right, I just prefer the 4 bolt flange for the interchangeability. I can do 11 inch drums to just about every GM disc brake set up. For me, it's worth the effort.
T
 

64nailhead

Goat Herder
Dec 1, 2014
5,659
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Upstate NY
It's actually a locker. The Max Lock Locker is Auburns version of the Powertrax Lock Right Locker. I'm well aware of the limits of these housings. The gears can handle 500hp but the housing flex is the killer. If i get bit by the track bug this season, I'll green light a girdle for this rear. A 8.5 build is in my future plans. View attachment 90769

That is a mini spool, just under Auburn's name from what I see. The 7.5's weakness isn't the housing, it's the pinion bearing and carrier bearings - they're somewhat small. Next on the weak link is the stock axles - G-bodies were built with 26 spline that mostly resemble a toothpick and the later 7.625's were built with 28 spline that looks like the 26 spline toothpicks on steroids. Then comes the housing.

A girdle is a big help on carrier bearing stability and is highly recommended by me if you're putting some torque to the road.

From what I've seen, iit is very rare to see a housing that has been flexed or bent to the point that the carrier doesn't fit correctly implying falls out when the carrier caps are removed. I'd guess this is due to that other components break long before that happens.
 
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jetsetw31

G-Body Guru
Sep 9, 2010
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Petersburg, VA
That is a mini spool, just under Auburn's name from what I see. The 7.5's weakness isn't the housing, it's the pinion bearing and carrier bearings - they're somewhat small. Next on the weak link is the stock axles - G-bodies were built with 26 spline that mostly resemble a toothpick and the later 7.625's were built with 28 spline that looks like the 26 spline toothpicks on steroids. Then comes the housing.

A girdle is a big help on carrier bearing stability and is highly recommended by me if you're putting some torque to the road.

From what I've seen, iit is very rare to see a housing that has been flexed or bent to the point that the carrier doesn't fit correctly implying falls out when the carrier caps are removed. I'd guess this is due to that other components break long before that happens.
I'm sorry, I wasn't specific. You're way right. I didn't mean the weak stock axles, gears, and bearings handling 500.. I meant with the good stuff at it's limit.
I actually have ARP studs for the bearing caps. My final piece would be a girldle. I'm a long way from beyond 500hp.
T
 

Zspoiler

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Jun 3, 2018
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I wouldn`t waste money on a 7.5 I would go with an 8.5 10 bolt if you to have any healthy power.
 
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jetsetw31

G-Body Guru
Sep 9, 2010
678
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Petersburg, VA
I wouldn`t waste money on a 7.5 I would go with an 8.5 10 bolt if you to have any healthy power.
Believe me, I have plans on a near bullet proof 8.5 with a upgraded rear suspension. This 7.6 build is needed and will do for now.
 

Zspoiler

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Jun 3, 2018
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We do what we can afford at the time.And save up to get what we want down the road.
 
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Oct 14, 2008
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Melville,Saskatchewan
For your power level, the bigger 7 5/8" gear should be plenty. You are getting rid of two big weak points, stock soft and puny 7.5" spider gears, upping to the 7 5/8" size lunch box locker will help, I broke the 7.5" size locker, as have others. The 28 spline Moser axles are another huge upgrade. I also went with a solid pinion spacer, supposed to help strengthen or go with the Ratech smart sleeve, supposed to be the best of both worlds. A girdle cover doesn't stop exploding spider gears from exiting, just slows them down:). The girdle cover no doubt helps and the G body housing is supposed to be more robust than the later F body housing.
 
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Rodney Pickering

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Mar 13, 2017
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0541DC02-9B29-4FCE-961F-AB556B6767D1.jpeg


Above is pic of stock 81 Malibu backing plates with 7/8th’s cylinder from s-10 and clamp. This is on 7.5 posi rear end from a 1985 Monte SS.
Will be running a 350-350 hp through a 200r4. Using for cruiser with a little pep.
 
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