XJ axle swap/build

[Nates2000XJ]

Originally Posted by DocTremp

That’s a good idea, I have some PVC lying around from my mock up links. For squaring your axle to the body, what landmarks did you measure from?

Thanks, I’ll check them out.


Sent from my iPhone using Tapatalk

hang the leaf springs and measure from outside face of the leaf pack to the inside face of the axle flange. You can measure from a bunch of things but leaf to flange seems to be one of the most reliable places to reference on each side. I did not account for the 1-2 degree compensation Rob mentioned. For what its worth, I haven't encountered leaf wrap symptoms. If I did, I'd look into an anti wrap bar before cutting off the U bolt eliminators and re-doing them.

[DocTremp]

Originally Posted by Nates2000XJ

hang the leaf springs and measure from outside face of the leaf pack to the inside face of the axle flange. You can measure from a bunch of things but leaf to flange seems to be one of the most reliable places to reference on each side. I did not account for the 1-2 degree compensation Rob mentioned. For what its worth, I haven't encountered leaf wrap symptoms. If I did, I'd look into an anti wrap bar before cutting off the U bolt eliminators and re-doing them.

Got it, thanks Nate. That makes a lot of sense. I’ve read in other threads about angling pinion 1-2 degrees, but I’ve heard from both sides that their set ups work without issue. I think it may be preference? Idk.


Sent from my iPhone using Tapatalk

[Nates2000XJ]

Maybe. May be spring stiffness, gear ratio/final drive ratios. I'd have to think on it and draw force vectors or something.

[maxbraketorque]

The notion of angling the pinion down 1-2 deg relative to the drive shaft is to compensate for axle wrap. For sure there is no reason to make the pinion shaft parallel to the drive shaft. Only question is how much to angle it down. Adams recommends 1-2 deg.

[DocTremp]

Originally Posted by Nates2000XJ

Maybe. May be spring stiffness, gear ratio/final drive ratios. I'd have to think on it and draw force vectors or something.

Aww man, take it easy with those force vectors haha. I enjoyed that part of physics, but I don’t use them too often anymore. I think spring stiffness if probably it, but I’m sure hear ratios have something to do with it as well.


Sent from my iPhone using Tapatalk

[DocTremp]

Originally Posted by maxbraketorque

The notion of angling the pinion down 1-2 deg relative to the drive shaft is to compensate for axle wrap. For sure there is no reason to make the pinion shaft parallel to the drive shaft. Only question is how much to angle it down. Adams recommends 1-2 deg.

I got ya. Sounds like that’s if you’re running leaf springs without a torsion bar, which is what I am doing, but I’d rather add a torsion bar to fix the axle wrap then change my pinion angle. The point of your pinion being parallel to the drive shaft is to limit vibration I believe.


Sent from my iPhone using Tapatalk

[maxbraketorque]

Originally Posted by DocTremp

I got ya. Sounds like that’s if you’re running leaf springs without a torsion bar, which is what I am doing, but I’d rather add a torsion bar to fix the axle wrap then change my pinion angle. The point of your pinion being parallel to the drive shaft is to limit vibration I believe.


Sent from my iPhone using Tapatalk

Actually, the angle needs to be slightly off parallel to drive the needle bearings in the u-joint to circulate. 1-2 deg (or maybe 1-1.5 deg) off parallel should be the target whether or not you plan to limit axle wrap with torsion bars.

[DocTremp]

I got ya, if the needle bearing don’t move then the life of the u joint is reduced. Thanks for the input.


Sent from my iPhone using Tapatalk

[89Mock]

I did my Sterling 1.25 using the ruff stuff +2 perches. Angle the pinion down 2 degrees. Part of the reason is so the u joints get lubricated while they rotate. If they’re absolutely perfectly at zero they’ll burn up, but this won’t ever happen on our Jeeps. The pinion just moves up more than you’d think. At first I did mine without the full weight on the vehicle. Do yours with the new tires on all four corners. That’s what you’re going to be driving with so that’s what you should set it up with. I took as many measurements as I could before assuming the axle was centered.

[DocTremp]

For those of you who have done wider axles, what length did you go with brake lines? I have 22” now and I don’t think it’s enough. Iron rock has 27” front and 22” rear as a combo, ruff stuff has 30” fronts but no rear. Any advice would be awesome, thanks!


Sent from my iPhone using Tapatalk

[Nates2000XJ]

My fronts are Crown extended XJ steel braided lines. 5-6" lift size iirc I picked the longest ones they offered. They are plenty long, my shocks droop out before the brake lines do. The rears was the steel braided line from the Crown kit and I kept the rubber soft and hard lines from my ZJ brake set up on the stock axles. I ended up needing to ream out the banjo fittings on the caliper side of the brake lines since the larger brakes used a larger dia banjo bolt. My larger brakes also benefitted from a larger master cylinder but that's not really related to lines. I'll try to post a photo or two

[DocTremp]

Originally Posted by Nates2000XJ

My fronts are Crown extended XJ steel braided lines. 5-6" lift size iirc I picked the longest ones they offered. They are plenty long, my shocks droop out before the brake lines do. The rears was the steel braided line from the Crown kit and I kept the rubber soft and hard lines from my ZJ brake set up on the stock axles. I ended up needing to ream out the banjo fittings on the caliper side of the brake lines since the larger brakes used a larger dia banjo bolt. My larger brakes also benefitted from a larger master cylinder but that's not really related to lines. I'll try to post a photo or two

Thanks Nate! I have 4-6 inch lift extended brake lines from RE and I wasn’t sure if they’d be long enough. I think I might just run them and see what stops the flexing first.
What MC did you end up running BTW?


Sent from my iPhone using Tapatalk

[Phil]

Have you relocated or removed the lower brake line clip on the body?

[Nates2000XJ]

Centric: 131.67025
Amazon link below. Look on Rockauto or other sites to find the best deal.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[DocTremp]

Originally Posted by Phil

Have you relocated or removed the lower brake line clip on the body?

I pulled them off for frame stiffeners and I have yet to relocate them.


Sent from my iPhone using Tapatalk