Define what does rear bolts do for your car.

[deeboe78]

Sorry still getting all the terms down. What is a 12 or 10 rear bolt? How can I find out whats on my car (chevelle 70). Does it enhanced peformance? sorry for the rudimentary question, but I dont know.


Thanks

SSG D

[69Camaro/70 Velle]

Just look on the back cover. If it's a 10 bolt it will have 10 bolts on the back cover. A 12 bolt will have 12.
The 10 bolt will have an 8.2 inch ring gear or something like that. The 12 bolt will have an 8.875 inch ring gear and is stronger.

[dhutton]

It's the number of bolts that hold the cover on the GM rear ends. 12 bolts are the stronger rear ends. However, there are some 8.5 inch 10 bolt rear ends (also called corporate rear ends) that are almost as strong as the 12 bolt versions.

Don

[Jimmy Sean]

12-bolt
https://static1.pt-content.com/images/noimg.gif

10-bolt
https://static1.pt-content.com/images/noimg.gif

[andrewb70]

Actually the number of bolts refers to how many bolts hold the ring gear to the differential. It just so happens to match the number of bolts on the rear end cover. A ring gear that is larger in diameter will be stronger, assuming the same material is used. That's the basics of it.

Andrew

[Jimmy Sean]

Actually the number of bolts refers to how many bolts hold the ring gear to the differential. It just so happens to match the number of bolts on the rear end cover. A ring gear that is larger in diameter will be stronger, assuming the same material is used. That's the basics of it.

Andrew


Well I learn something new every day.

[silver69camaro]

Andrew's right. Some ring gears that use 12 bolts have 10 bolts on the diff cover. I think some Old's housings were that way.

[69cutlassrkt]

the 12 bolt olds uses 12 for the cover and 10 bolts for the ring gear

[dhutton]

Well I learn something new every day.

Me too.

Don

[wendell]

the 12 bolt olds uses 12 for the cover and 10 bolts for the ring gear

The classic "Ebay Special" 12 bolt!

[deeboe78]

Just look on the back cover. If it's a 10 bolt it will have 10 bolts on the back cover. A 12 bolt will have 12.
The 10 bolt will have an 8.2 inch ring gear or something like that. The 12 bolt will have an 8.875 inch ring gear and is stronger.




back cover?

[BonzoHansen]

Actually the number of bolts refers to how many bolts hold the ring gear to the differential. It just so happens to match the number of bolts on the rear end cover. A ring gear that is larger in diameter will be stronger, assuming the same material is used. That's the basics of it.

Andrew

That is my understanding of it. And why a 7.5" 10 bolt 4th gen rear is weaker than an 8.2" 10 bolt 1st gen rear, which in turn is weaker than an 8.5" 10 bolt 2nd gen rear. I think I need a scorecard, lol.

[silver69camaro]

the 12 bolt olds uses 12 for the cover and 10 bolts for the ring gear

Ah, gotcha. Had it backwards.

[WS6]

back cover?

This is the cover on the back of the rearend. Get down and look under you car at the rearend. You'll have the two tubes coming out either end that house the axles and go to the wheels. They originate from the differential. There is a cover that well covers the differential and allows the oil to stay in there and yet still allows servicing of the diff once the cover is removed. That cover will have 10 or 12 bolts holding it onto the rearend.

[yellowrallys]

Also for a quick inspection just by looking under the rear of the car, without actually counting the bolts in the cover, refer to the pictures a few post back. A 12 bolt has two bolts side by side in the bottom of the cover, 10 bolt has one bolt in the bottom center.

[GBodyGMachine]

actually the number of bolts refers to how many bolts hold the ring gear to the differential. It just so happens to match the number of bolts on the rear end cover. A ring gear that is larger in diameter will be stronger, assuming the same material is used. That's the basics of it.

Andrew

bingo.