Front Pinion Angle vs Caster

[Nelson]

I have an issue with the front pinion angle and caster. First of all I built a set of long radius arms 10.5" longer than stock. I built in 3.5* of caster into the arms at this time. Now after paint and final assembly I am addressing the minor issues that go along with all the mods. I found this and it was expected but now what to do.
Heres the info: I have a 3.5" lift with long arms as mentioned above with 7* c bushings installed and 7.9* of caster. The pinion angle is off by 6.2* low as compared to the driveshaft angle.
I have an old set of 2* and 4* c bushings and have put them in to find out which one to go with to help the pinion angle and still have a good caster angle.
Here are all the numbers please give insight as to which way I should go. PS I know I can always cut and reweld the inner C's to get the caster back but is it worth it for the pinion angle I have with the lower degree c bushings.

2* bushings installed: Pinion to driveline angle offset is 1.1* caster is 2.4*
4* bushings installed: Pinion to driveline angle offset is 3.1* caster is 4.3*
7* bushings installed: Pinion to driveline angle offset is 7.9* caster is 7.9*

Do I go with the 2* and see how it drives or 4* with good caster and poor pinion angle. It is used 50/50 on and offroad 3 and some 4 degree trails offroad.

Thanks IA Nelson

 

[TBS-POPS]

I would try the 2* bushings and see how it drives. different broncos react differently to various degrees of caster. yours may drive just fine with the 2.4*. Tire size and tread pattern also affect how a vehicle will react to different degrees of caster.

 

[Nelson]

I am doing all this to get a good measurement for the driveshafts. Tires are 35" km2's on 15" x 8" wheels. My son and I left the old 2* c bushings in and have kinda decided to maybe run it with them to see how it does.

Thanks Nelson

 

[Broncobowsher]

I would be looking at the 4° bushings. The caster numbers look good and only 3° of driveshaft angle is no big deal. Especially considering when running at highway speeds you just unlock the hubs and leave it in 2WD and at that point the driveshaft is irrelevant.

 

[garberz]

My buddy extended his radius arm and the increased caster made for a bad pinion angle. We switched from 7* bushings to 4* and then ran one of these offset u-joints to help with the binding.


http://www.wildhorses4x4.com/product/Super-Flex_U-Joint

 

[Nelson]

I have seen those offset u joints on Tom Woods site. That may be an option with the 4* bushings. Thanks for the ideas I will call TW tomorrow and ask about this option.

Thanks Guys

 

[Apogee]

If you intend to ever run in 4WD at speed, I'd just rotate your knuckles and be done with it. It seems like you took the effort to make your own radius arms, so clocking the C's isn't that much more work and would allow you to run either the rubber or poly non-degreed bushings and pick your pinion angle. Otherwise, you're just compromising between caster and pinion angle.

 

[Justafordguy]

X2 on rotating the knuckles.

 

[Nelson]

I have a set of cam ball joint bushings on order from napa to get the caster back to around 4*. I think I will probably run the 2* bushings as a test and make up my mine after the test drive period. I wiil not be using 4Hi for the road with the front locker. Right now I just want to drive it and don't really have the enthusiasm to do the inner C's. But may change my mine after I drive it.

Thanks for all the suggestions
Nelson

 

[Justafordguy]

It will drive better with closer to 8 degrees of caster than it will with 4.

 

[Ranchtruck]

With power steering, the more caster the better. Run at least the 4 degree bushings. It will be more stable and easier to drive. Caster is what makes the steering wheel return to center as you come out of a turn. It also gives you the steering feel to control a slide.

 

[Nelson]

I will try the 4* after the test drive with the 2* and the ball joint eccentrics. Just want to rule out all the possiblities before I have to pull everything and take the time to cut the inner C's.
I am not sure if the driveshaft angle of 3*'s on the CV joint will be a problem on the trail even at low speed. With the longer radius arms and rubber arm bushings at the frame end it may flex into binding and break something. I know the if I cut the C's I will have no worries but it has been 6 long years and I am growing tired and would like nothing better than to drive it for a while to get my motivation up. I still have more broncos to build, one buggy and one stock in retirement. As of now I am waiting on other people again to get some things finished up before I can drive it.

Thanks Nelson