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Author Topic:   rearend
19J
Dirt Freak

Total posts: 370
posted April 01, 2004 09:32 PM  
Ok i seen a bunch of people talking about the chevy rearends. My question is how do you tell the difference between the 7.5 and 8.5?

nate 11
Dirt Freak

Total posts: 316
posted April 01, 2004 10:07 PM  
i think the rear cover is different. i seen pics on this site some where check the tool box. or you can take the rear cover off and look at the numbers on ring gear, it will say' along with part number and number of teeth on ring and pinon gear. hope this helps.... later

maxwell
Dirt Full Roller

Total posts: 46
posted April 02, 2004 11:25 AM  
i think the tubes coming out of the center section are slightly larger on a 8 1/2"

racer17j
Dirt Forum Champ
Total posts: 5390
posted April 02, 2004 03:14 PM  
Thats the only way to tell the difference? How do you get a 12 bolt? I have a 12 bolt gear but dont know what rearend i need.

racer17j
Dirt Forum Champ
Total posts: 5390
posted April 03, 2004 12:54 PM  
Not sure we are all on the same page here. 7.5 versus 8.5 is talking about ring gear diameter. 10 and 12 bolt is talking about cover housing bolt count. If you have a 12 bolt ring gear you need to measure the diameter of it and that will tell you what rearend housing it goes in or will fit. From what I am reading here that is more in line with your question anyway. Good luck

19J
Dirt Freak

Total posts: 370
posted April 03, 2004 10:57 PM  
Ok. Let me get this straight. I have a 12 bolt so i need a 12 bolt rear end but the only way to tell if it is a 12 bolt is by the gear? Can a 7.5 have a 12 bolt gear in it or what? I need to know what to look for. Does a 12 bolt have a 12 bolt cover? Thanks for all the replies.

nate 11
Dirt Freak

Total posts: 316
posted April 04, 2004 12:32 AM  
not sure what your asking about 7.5 with a 12 bolt gear. yes a 12 bolt will have 12 bolt cover. ....hope this help....later

19J
Dirt Freak

Total posts: 370
posted April 04, 2004 09:40 AM  
Ok. Is all 12 bolts in the 8.5 rearend? I got a 8.5" gear that is 12 bolt. I need to look in chevelles and that? Thanks for all the help.

BK19
Dirt Freak

Total posts: 477
posted April 04, 2004 10:56 AM  
http://www.geocities.com/MotorCity/Flats/8607/rearend.html

You can see the difference in the 7.5 and 8.5 in the pictures here. Notice the little "curls" at the bottom corners of the 7.5 and where the 8.5 is squared off at the lower corners. Every 12 bolt I have seen had a 12 bolt cover, car and truck. The ring gear diameter on a 12 bolt is 8.875" or 8 7/8".

JRB13
Dirt Forum Racer

Total posts: 80
posted April 05, 2004 09:16 PM  
ANOTHER DIFFERENCE IS THE 8.5 AXLES BOLT IN THROUGH THE BACKING PLATE ALSO THE 7.5 AXLE TUBES ARE KINDA KINKED ON THE END WERE IT MEETS THE BACKING PLATE WERE THE 8.5 ARE STRAIGHT ALL THE WAY ACROSS HOPE THIS HELPS

19J
Dirt Freak

Total posts: 370
posted April 05, 2004 10:11 PM  
Thanks for all the replies.

BK19
Dirt Freak

Total posts: 477
posted April 06, 2004 06:47 PM  
the buick olds pontiac have bolt in axles chevy have c clip on the 10 bolt with the 8.5 ring gear

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