12 bolt & 35's

[superhondaz50]

I can't seem to find a decent answer, but how well will a 12 bolt hold up to 35's? Truck will be geared with 4.10's and will only be used to tow (2500lbs). Will I be blowing up u-joints, etc? Thanks

[57taskforce]

Back in the 90s my dad had a 72 K10 with 38.5 ground hogs under it. It had a built 350, sm 465, 205 in it. He used to play in the mud pretty hard with it and never blew the 12 bolt or anything else drive train related for that matter. If your smart with it 35’s and 4:10s should hold up fine. The truck 12 bolts are reasonably strong for 1/2 ton stuff in my opinion.

[special-K]

You'll be fine. The 4.10s will help. Get crazy with it and that's another story

[cleszkie]

I've personally seen two truck 12 bolts "turn" their center sections under reasonably heavy abuse (one while towing, another while playing). When I say turn, I mean the axle tubes spin in the center section under torque load. As a precaution, people will beef up the puddle welds in the center section, or even attempt to weld the tubes directly to the center section. But as we all know, welding steel to cast iron is an iffy proposition at best unless the cast iron is properly pre-heated.

[superhondaz50]

Ok, just gonna play it safe, putting on metric 33's (305/70r16) with 3.73 gears. Should be a lot less stress and still maintain an agressive look.

[bw46]

I would do it without hesitation. I have personally put 800 HP and 750 ft. lbs of torque (at crank) through a 12 bolt, with sticky 11" wide tires, launching as hard as I can. no problems to date. While this is not towing with 35s, it's still a pretty hard shock load to the 12 bolt.
I like the suggestion of beefing up the puddle welds as per prior member.

[superhondaz50]

I'll look into beefing up the welds, I've never done steel to cast iron, so I need to research that first.

[Mike C]

Avoid wheel hop at all costs. The auto trans will help with that. I found the sm465 and 35" tires awful hard on 12 bolts. But some of that was probably my enthusiasm 30 years ago...

I have a SF 14 bolt in my truck. Mine is converted to 8 lug now, but the 6 lug 14 bolt in 3.73 is a great replacement for the 12b and it is much stronger.

[superhondaz50]

Is it a pain in the dick to put a 14 bolt on? Can they be converted to 5 lug?

[Mike C]

Anything can be done with enough $, but it can't be converted to 5 lug easily. With 35's I was assuming this is a 4x4 truck is it not?

[indymachinist]

As for the driveshaft, 1350 u joint pinion yokes are available for the 12 bolt if you want more strength.

[superhondaz50]

Lifted 2x4, I'm gonna check out those u joints.

[57taskforce]

How the hell did you cram 35s under a 2 wheel drive?? Haha

[superhondaz50]

88-98 4" spindles, 2" coil spacer. Have 3" body lift I can put on if I wanna go taller.