GM 12 Bolt questions?

[gmcjimmy88]

I currently have the 10 bolts under my jimmy. I know I need to upgrade. Was originally looking at the 60 rear and 44 front but haven't had luck finding them cheap enough. Found a cheap set of 12 bolts and thought they might be stronger? Are they worth the swap or should wait until I find the 60/44? I will be running 36-38 inch tires, 513-538 gears and I have never been known to have a light foot with the pedal. I know the 10 bolts wont hold up but what is everyone's opion on what axles to run?

 

[cybrfire]

To my knowledge there is no 12 bolt front in existance. There may be some custom thing out there as I have seen a 14 bolt front that was custom built.

That being said when price is considered I would go with a 14 BFF in the rear. Gear selection is the problem hear. Several places working on lower gears.

Front is a little tougher. You may get a 10 bolt or a 44 to hold up for quite a while. If you start having to replace parts it may have been better to hold out for a 60.

 

[R72K5]

yeah fronts are 10 bolt 8.5" same as rear 10 bolts, and dana 44's, under everything cept 1 tons,

and dana 60 were under (front of) 1 tons only

rears were 12 bolt through 82 and 10 bolts starting in 77-79 years

12 bolt has smaller pinion stem diameter, by quite a bit and have a pinion nut loosening issue, very commonly

personally i favor the 10 bolts over the 12 bolt truck axles

and off topic but car 12 bolt is a whole different story, as they have the big pinion stem in them

if i were to pick a 1/2 ton rear i'd stick with 8.5" 10 bolt,

good luck

 

[gmcjimmy88]

Here is the pic of the ones I am looking at? He says they are 12 bolts front and rear

 

[Hossbaby50]

The front axle will either be a 10 bolt front or a Dana 44. There is no 12 bolt fronts. If you plan to run 36-38" tires I would go with a Dana 60, Dana 70, Sterling 10.25, or 14bff rear. The 10 bolt front may be able to last awhile if you drive light but most likely if you do any actual wheeling sometime it will break something.

The 14bff is the easiest and strongest swap but it takes away the most ground clearence. The D60 rear would give you better ground clearence but won't be as easy to swap in most likely and won't be as strong as the 14bff (although it is much stronger then you 10 bolt). D70's are stronger then D60's but are harder to find. Sterling 10.25's or 10.5's are a great option also. They are under Fords and should have comparable strength to a 14bff but have better ground clearence. They are harder to swap though.

The front is one of 2 option's. Run a 10 bolt or D44 (which are comparable in strength) or swap in a D60 front.

Harley

 

[Z3PR]

Dana 60 front / 14 bolt FF rear. It's a proven combo. Now, Dana 60's front and back with ( read about this ) would be way cool.

 

[blazerpro79]

Dana 60 front / 14 bolt FF rear. It's a proven combo.

that seems to be what almost everyone is running, one of the best axle setups

 

[bagged beast]

im running 14 bolt and 35 spline outer 60 and i would never have it any other way. I had 38 on a blazer with a 10 bolt front and d60 rear that i had before this rig and when we went on trips it wasnt "if" it would break but how long i could go before it broke and being broke on the trail sux

 

[UseYourBlinker]

You can buy my Moser axles $200 for a 10 or 12 bolt.

 

[tRustyK5]

I'd consider the 10 bolt or D44 front if you're sticking to the 36" size and you keep the front open and don't spend any money on it. Much beyond that and you will quickly get lot's of practice fixing it...

For the rear the 14 bolt FF is such an easy swap. You can shave the bottom and gain about 3/4" of ground clearance back. I'd be willing to bet better than 70% of the guys running 14 bolts have done this.

If you're leaning towards the 38" size I'd run the 60/14 combo, because having to baby it all the time gets really old fast...

I did sucessfully run a D44 front and 14 rear with 36's for a couple of years. Never really broke anything, but did have to replace axle U-joints twice. Both times I got lucky and heard them creaking badly and was able to nurse them to the trailhead, then drive home and fix it there. Both times the needle bearing were crushed and the cups were cracked and broken. If I would have been in a tougher spot they certainly would have grenaded...

Oh yeah, there are no 12 bolt fronts.

Rene

 

[MEPR]

a buddy of mine (pvfjr here) is running 36" swampers whith a 44front nd a 12bolt rear. last time i was out whith him he was playing the roll of throtle jockey and the axles held fine. Grantted he has a 350 that has sen better days but he is running a 465 so the shock through the axels when he dumps the clutch is still perty signifigant. So iwould say a d44 or 10bolt front whith a 12bolt rer would be fine.