Fixing front pinion angle

[Cottontail]

I got a set of adjustable UCAs this week and am working on getting them installed.

I took the old fixed ones off, and when I did, the axle rotated so the pinion angle is way high.

I can't seem to figure out the best way to rotate it back down below optimal angle, so I can start the process from being too low.

Any suggestions?

 

[akendal4]

I use a large ratchet strap attached to the bottom of the inner c and the bumper. Then I tighten it until it moves to where I need it.

 

[trippled]

Yup ratchet strap works like a champ

 

[Tim_MN]

I prefer a bottle jack on the coil spring mount.

 

[Cottontail]

Assuming you are doing these options with the tires off the ground or the tires off the car altogether?

Are you doing these options on just one side or both simultaneously?

 

[TRCM]

You could try wrapping a ratchet strap around the top of the pinion, under the axle housing, and then back up to the front bumper/tow hook/swaybar mount area.

That will force it to rotate down pretty easily. It will also lift the front axle slightly (which will also force it to rotate down) to help get the lower arms back in.

 

[Cottontail]

Lowers are in....but it sounds like the ratchet strap is the way to go...

 

[akendal4]

Assuming you are doing these options with the tires off the ground or the tires off the car altogether?

Are you doing these options on just one side or both simultaneously?

Yes I always do it with the axle on jack stands. Wheels don't have to be removed but it does make it easier to work around

 

[rockclimber]

So much easier to just pull the springs and set it properly.

 

[the_weirdo]

Bottle jack under the front portion of the coil bucker, or regular jack under the steering arm of the knuckle.

 

[lazyxj]

I work by myself most of the time and a come-a-long is one of the best 'assistants' to have, when installing control arms.
http://www.harborfreight.com/2-ton-cable-winch-puller-61964.html

 

[WyoCherokee]

I jsut did this myself, and i used a come-along under the bottom of the pinion and back to the hitch of my truck. I think for future use, i am going to dead head bolts into my garage floor for a large D-ring.

 

[TRCM]

I jsut did this myself, and i used a come-along under the bottom of the pinion and back to the hitch of my truck. I think for future use, i am going to dead head bolts into my garage floor for a large D-ring.

That works for the rear............

 

[md21722]

Like Tim, I have targeted the spring perch, except I used a 4x4 with a floor jack. If more is needed, I've used a 10,000# ratchet strap. Any smaller ratchet strap tends to destroy the ratchet part. Overall it is usually easier to do one arm at a time.

 

[akendal4]

Like Tim, I have targeted the spring perch, except I used a 4x4 with a floor jack. If more is needed, I've used a 10,000# ratchet strap. Any smaller ratchet strap tends to destroy the ratchet part. Overall it is usually easier to do one arm at a time.

I agree that it is easier to do one arm at a time but only when changing to arms of the same length. I just did this Saturday for the rear uppers on my dad's TJ. However, in this case, he's going to longer arms so one arm at a time would be much more difficult.

 

[Cottontail]

The tilting of the pinion using a bottle jack on the front of the right coil bucket did the trick.

I was able to get everything set and tightened down. Haven't taken it out yet, to see how it feels, but everything looks good. Angles on the pinion and front drive shaft are equal.

Great help y'all. Thanks!

 

[AceWhite]

I believe the ideal setting is 6 degrees less than driveshaft angle, but it looks good. Check your caster/ tire angles. If it's off you can reset that pinion to fix caster angle.

 

[Cottontail]

According to my research, the front pinion should be equal to that of the driveshaft.

 

[AceWhite]

That may be true for the rear, but the front is a different story. There's some tire geometry at work in the front ie: caster or tire tilt, so it's not a simple point it at the t-case and be done.
Whatever works for ya tho

 

[ehall]

I use jack stands under the frame behind the LCA buckets, and then ratchet straps to pull the axle forward or backwards as needed. Loosen all the hardware first to release the binding, and do one arm at a time

As for length, you need to calculate caster and pinion angle (pinion -2 degrees), then favor the pinion angle as much as possible; it will eat u-joints if its set too steep. If you can't handle the steering, roll it back until you are comfortable, but not so much that you get vibrations. Its a trade-off.