Whats the difference between a 10bolt and 12 bolt rear axle.

[SimonUK]

Probably been answered dozens of times here but whats the difference between a 10bolt and 12bolt rear axle?

Since destroying my 3.08 10bolt a few weeks ago I've come across a 3.08 12bolt which seems to be in good condition so it will hopefully be getting fitted in the near future.

Simon.

[DmaxMaverick]

Have a look at THIS THREAD.

[Robyn]

If you dont mind a little bit of work a later model 14 bolt will fit. They were made with 6 bolt axles as well as the 8 bolt.

The job will require some relocation of the spring pads and such but its an easy task.

The 12 bolt was the factory install on the older GM 4x4's such as early Burbs and Blazers. They used the Dana 44 up front at that time.
The change came and they went to a 10 bolt on both ends of the 1/2 ton rigs and the 3/4 tons got a slightly different setup depending on the RPO but had a 10 bolt front.

The 12 bolt rear will do a fine job though but is not all that much stronger than a 10 bolt.

If the price is right its probably a good score.

Robyn

[DA BIG ONE]

The 12 bolt carrier R&P all fit the 10 bolt housing while not much larger they are supposed to be much stronger...................

[DmaxMaverick]

The 12 bolt carrier R&P all fit the 10 bolt housing while not much larger they are supposed to be much stronger...................

Been there, done that. I tried to get a 12 bolt carrier/RP into a 10 bolt. The 3.42 fit, but 3.73 and 4.10 didn't, and I wanted a 4.10, but would have settled for 3.73. Not enough clearance for the ring gear w/o machining the housing, and IMO, are weak enough already. Also looked like shimming would be a problem, but workable. I replaced the 10 bolt in my '85 with a '78 12 bolt. The 18 monthl rear end replacement interval came to a screeching halt. First 180K miles and a bunch of 10 bolt rebuilds, and the rest of the mileage with the first 12 bolt. After a couple 10 bolt rebuilds, thought I had a warped axle housing. Replaced the whole thing with all new. No good.

The 14 bolt SF is a good axle, but no better than a 12 bolt in a 1/2 ton or LD 3/4 ton, IMO. And, all the bolts and brake parts line up w/o mods when switching from the 10 to 12. The 14 bolt will take some torch/welding time and a few trips to the hardware store.

BTW:
I have a good (subjective term) 10 bolt housing and axles free to anyone in need. No carrier, RP, bearings, shims or side gears. They all went through the cover, which is also no good, unless you like yours well ventilated.

[SimonUK]

Thanks for the responses folks.

The axle came with a 10bolt front which is slightly different to the front on my 1009 cucv. Will need to check up on front axles as well. could be a Dana 44 as mentioned in the other thread.

Got both axles and a load of other spares of Jim Twaddle for the equivalent of a couple of hundred bucks.

I don't get much spare time just now hence the reason I asked the original question as I just dont have the time to do any research.

Suppose my next question is going to be...
Is the Dana 44 stronger than the GM 10bolt

Simon

[DmaxMaverick]

......Suppose my next question is going to be...
Is the Dana 44 stronger than the GM 10bolt

Simon

Marginally. Depending on how you use it, it may not make any difference. The 10 bolt front axle is fine, but if it's overworked (like rock crawling), the gears and bearings will part company. For 1/2 or LD 3/4 ton use, either is very capable.