Weight difference between axles

**JwMonE99** · 02-19-2009, 11:00 AM

I am upgrading to a moser 12 bolt.
With the 4.10 gears and detriot locker.
How much extra weight am I looking to add?
Also the 10 bolt is a 7.5 inch, what is the 12 bolt "inch" size?

**bigrondownhiller** · 02-19-2009, 01:32 PM

12 bolt is 8.875".

**JwMonE99** · 02-19-2009, 02:59 PM

How much heavier is it over the 10 bolt?

**JwMonE99** · 02-20-2009, 08:45 PM

No one knows how much a 12 bolt or a 10 bolt weights?

**Paul Huryk** · 02-24-2009, 08:56 AM

About 40lbs... Strange 12 bolt to a stock 10 bolt.

**ProwlerZ** · 02-26-2009, 07:37 PM

It will pull about .5" off your 1/4 mile time. There's a moderate weight difference, and a huuuge rotational mass difference. I understand the idea of upgrading the rear as planning for a future build, but you're about 200rwhp away from needing it, and you'd be better off building a 10 bolt. Just my .02

**Paul Huryk** · 02-27-2009, 04:58 AM

Originally Posted by ProwlerZ

It will pull about .5" off your 1/4 mile time. There's a moderate weight difference, and a huuuge rotational mass difference. I understand the idea of upgrading the rear as planning for a future build, but you're about 200rwhp away from needing it, and you'd be better off building a 10 bolt. Just my .02

The rotating assembly is only a few lbs heavier than the 10 bolt, the unsprung weight is 40lbs heavier - two different things.

When i did back to back testing at the track, there was zero difference in times and mph that I ran. 3.42 10 bolt vs. 3.42 12 bolt.

**pajeff02** · 02-28-2009, 07:49 AM

I think it was Car Craft a few months back that had a good axle comparison article. Best recollection is that they had a 9", a 12 bolt, and an aftermarket axle. As I recall, axle weights were listed, but it primarily focused on the horsepower differences which resulted due to the pinion offset from the ring gear centerline. Interesting article...