Best method to set a perfect wheelbase?

[xjbubba]

Caster/camber variances from side to side can cause pull to one side.
The fact that your driver's side upper ball joint is 1/16 farther away from the rear axle, than the passenger side upper joint implies a difference in caster.
Do a little "googling" to ascertain the affects of unequal caster/camber.
If, in fact, you do have significant variances (results of Google search),your solutions are limited, with the easiest being adjustable ball joints.
As I recall, steering will pull to the side having the least caster.

 

[98stocker]

Measure opposite corners, like left rear axle tube to right front ball joint and see if they are equal.
Check air pressure and tire wear.
Bleed your brakes. Long shot...
Check for a bent front axle housing.

 

[Builderxyz]

Considering you have done everything you can i would take it to a professional and have it looked at.sometimes it's just necessary my.02

 

[Highway XJ]

I vote for the unequal caster idea. Seems I herd that the Dodge 4x4 2500's are set with different caster side to side to stop the right hand pull. I have done all I can and i still have a slight right pull that gets worse with more speed and the caster fix makes most sense to me. I have adj upper and lower CA's sop I can put a little stress on the caster but would have to twist the front housing to change the caster side to side. Not going to do BJ's just to correct some pull. Really should have it lazzer sighted to see where things are. BTW, seems I read that the driver side has about 10mm shorter WB to allow for road crown pull to the right.

 

[muddeprived]

I vote for the unequal caster idea. Seems I herd that the Dodge 4x4 2500's are set with different caster side to side to stop the right hand pull. I have done all I can and i still have a slight right pull that gets worse with more speed and the caster fix makes most sense to me. I have adj upper and lower CA's sop I can put a little stress on the caster but would have to twist the front housing to change the caster side to side. Not going to do BJ's just to correct some pull. Really should have it lazzer sighted to see where things are. BTW, seems I read that the driver side has about 10mm shorter WB to allow for road crown pull to the right.

That's the weird thing. It should be pulling to the right cuz PA roads are crowned and my wheel base is the same on both sides.

Would that small 1/8" difference in caster cuz such a pull that overcomes the crown of the road and still pull to the left?

I just gotta take it to an alignment shop and get an accurate print-out of the specs to know for sure.

 

[Highway XJ]

When you stop the left pull you'll probably get the DW,,,,lol.

 

[Otter]

swap front tires side-to-side. eliminate the possiblity of a bad tire.

 

[muddeprived]

swap front tires side-to-side. eliminate the possiblity of a bad tire.

That's the first thing I did a couple weeks ago. I ordered a set of 265/75/16's from treadwright not that long ago and I swapped em around twice. Didn't change anything. I was thinking I had a radial pull.

Thanks though.

 

[muddeprived]

When you stop the left pull you'll probably get the DW,,,,lol.

(knocking on wood)

:gag:


lol

 

[Highway XJ]

My tire guy called it " radial pull". A tire that pulls to one side.

 

[muddeprived]

My tire guy called it " radial pull". A tire that pulls to one side.

How do you overcome a radial pull? The first thing I tried weeks ago was to rotate the tires to the opposite side like "X". Still had the same pull.


I drove an hour to the city today and it was pulling to the left still. The wheelbase is the same on both sides. I adjusted the upper arms to get the caster even on both sides as well. I felt the brakes when I arrived home and both were about the same temp (i could leave my finger on for about 3 seconds) so they are not dragging. I replaced the upper arm flex joints and tested the lowers and nothing wrong with em. So what else can cause such a strong left pull that requires constant correction? It seems to be heavy at highway speeds and very little when driving around town. PA roads are crowned so the jeep should be pulling to the right very slightly but it's overcoming that and going left.

 

[CaliXJ]

I'm getting replacement joints for my RC long arms and they are sending me a replacement crossmember as well

Thanks


Chris

I'm wondering how you got a replacement X member from RC. I bought my kit just befor they changed it to the hidden trans bolt style. :wierd:

Sorry for off topic.

Have check your rear brakes? Maybe you have a rear shoe dragging or not adjusted right? How are your front hubs?

 

[whitexj98]

I was just scanning the thread soI might have missed it but, what is your castor set to?

 

[muddeprived]

I'm wondering how you got a replacement X member from RC. I bought my kit just befor they changed it to the hidden trans bolt style. :wierd:

Sorry for off topic.

Have check your rear brakes? Maybe you have a rear shoe dragging or not adjusted right? How are your front hubs?

Jeffrey from RC pm'd me on jeepforum out of the blue and offered to exchange my crossmember, fix my joints, and also send me a bent upper arm cuz of the high pinion clearance. I wasn't thrilled back when they changed the xmember design on the kits so I spoke with Ron at 4wheelingplus (where i bought my kit) about this and he agreed that it wasn't right so he tried to speak with RC and see if they could exchange but was turned down and told I would have to pay $199 for the new one. I declined and posted about it in the thread on jeepforum. Somehow Jeffrey FINALLY saw the complaint thread and offered to fix it. That was nice of him. I was about to fab up a raised mount when I got his PM. Good timing.

I unadjusted my rear brakes to test this theory out so only the front brakes were doing all the work and it still pulled. Then I adjusted them back to normal and no change.

 

[muddeprived]

I was just scanning the thread soI might have missed it but, what is your castor set to?

I didn't really measure my caster. When I had my LP30, the caster was 3 degrees, kinda poopy. I got the caster print-out at Midas. I found a HP30 for cheap so I swapped that in and aligned the shaft with the pinion and it drove so much better cuz I was able to get more caster with the HP without getting vibes. I did measure the caster on both sides using the upper and lower ball joints and both say 6 degrees. I know that's not the actual caster number but they are identical on both sides.

 

[4.3LXJ]

Mud

Establish a reference point in the center of the vehicle, like where the cross member bolts on. Measure to the front and rear of the vehicle to frame make sure it is centered accurately. But I think these are. Then measure to front and rear axle housings for your wheel base.

On another note, I can't remember if you checked camber and castor during alignment. Both can cause a vehicle to pull.

 

[lazyxj]

I found this on Go Jeep's alignment page, at the end of the article.
One side has a slightly longer wheel base (10 mm) to prevent pulling due to the center crown.
http://www.go.jeep-xj.info/HowtoAlignment.htm

"Just a little note for Australian owners or any RHD ones, if you have trouble of it always pulling left following the camber of the road, check your wheel base left to right and you will find that the left side is 10 mm shorter than the right! This is so it will run straight on USA or on the right side of the road which of course is the opposite of what we want. I had to add an extra 10 mm shim to the left side LCA and also remove the UCA, weld up the diff end holes of it and re-drill them 10 mm forward so that my wheel base is the same left to right. It still follows a steeply cambered road a small amount but on freeways it is perfect. To follow the Jeep logic for this you would need to extend a further 10 mm to have the same as their stock setup! My tyres now wear nice and evenly too."

 

[muddeprived]

I found this on Go Jeep's alignment page, at the end of the article.
One side has a slightly longer wheel base (10 mm) to prevent pulling due to the center crown.
http://www.go.jeep-xj.info/HowtoAlignment.htm

"Just a little note for Australian owners or any RHD ones, if you have trouble of it always pulling left following the camber of the road, check your wheel base left to right and you will find that the left side is 10 mm shorter than the right! This is so it will run straight on USA or on the right side of the road which of course is the opposite of what we want. I had to add an extra 10 mm shim to the left side LCA and also remove the UCA, weld up the diff end holes of it and re-drill them 10 mm forward so that my wheel base is the same left to right. It still follows a steeply cambered road a small amount but on freeways it is perfect. To follow the Jeep logic for this you would need to extend a further 10 mm to have the same as their stock setup! My tyres now wear nice and evenly too."

Right, my passenger side wheelbase is supposed to be slightly longer to overcome the sloped roads here in PA. My wheelbase is even on both sides (according to the way i measured) so it should be pulling to the right a little but it's actually pulling pretty good towards the left.

I'm gonna do what 4.3L said and check wheelbase from a reference point on the frame. When I measured, I used the distance from rear axle tube to front ball joint, not from a point on the frame rail. We'll see if there is any difference.

 

[muddeprived]

Ok i re-measured using a bob as a reference point. I used the front leaf spring bolt to hang the bob from. Here are the measurements:

Driver's side:

Front axle tube to bob: 76 1/2
Rear axle tube to bob: 21 3/16

Passenger side:

Front axle tube to bob: 76 1/2
Rear axle tube to bob: 21 1/4

The passenger side rear axle is just a hair less than 1/16" further from the bob than the driver's side. Would THAT cause a strong left pull?

I also checked front and rear brakes with tires off. The front brakes have no resistance at all when spinning them BUT the inner rotor surface is starting to wear out on both sides. You can see the rotor surface gone on some spots but not completely. I'm gonna have to replace the rotors. Both sides are evenly worn.

When spinning the rear brakes, the driver's side has a little bit of resistance on one section of the drum, about 1/4 of the way around but the rest is smooth. The resistance is not strong and I can still spin them through it without much muscle. The passenger side has no resistance. I plan to loosen the driver's side rear adjuster so there's no resistance but not sure if that will make any difference.

I measured the front axle placement using my sliders as refence point. Both stick out just to the end of the sliders on both sides so the axle is centered.

All my steering joints are tight and I doubled checked em. I DID notice something funny with the steering today when stopping as sister's house. I pulled over to the side of the road and parked it to drop something off. Then i came back, started it up, and had to turn left to pull out from behind her tracker. When turning the steering wheel to the left from a complete stop, it would squeak pretty bad and I could feel it through the steering wheel. When the tire was done turning (still stopped) I could feel a slight clunk or thump in the steering. It kinda felt like there was some slop in the gears that when you stop it falls back into the gear. It only does that when turning the steering wheel quickly and stopping the turn suddenly (when at a standstill). I just replaced my box with a reman about two years ago and also the power steering pump. Now I'm wondering if the box is bad and causing the pull?

 

[xjbubba]

Giving all the checks you've performed so far, I'd be inclined to have your alignment checked by a reputable shop, then post the results here.
Home-brew approaches to checking caster and camber are a guess, unless you have the proper equipment that can measure angle differences from side to side dynamically. Caster/camber will change from side to side with changes to toe and steering inputs. I've observed an alignment shop try to correct a left to right variance in caster by adjusting the UCA's on my Jeep! Obviously, with a solid axle, it can't be done. Well, between UCA adjustments, and readjusting toe, the machine indicated he had, in fact changed the caster readings, side-to-side! The fact is, as the wheel rotates on a horizontal plane, steering inclination affects both apparent caster and camber as the wheel moves past the straight ahead position. Fortunately, the numbers cannot be manipulated in such a manner that the total results are within factory specs--so the reported results still indicate a caster problem (numbers outside factory specs). In my case, the inner "c" on one side was not accurately installed (after market axle build). But, unless you've bent an axle, or inner "c" through accident, jumping, or hitting an obstacle, I wouldn't expect you have in incorrectly positioned inner "C". I found the problem because the alignment shop couldn't bring the readings within tolerance. I disassembled both ends of the axle, down to the inner "C's". At that point, an angle finder can be accurate in checking base steering inclination and camber. It's easy to use angle finders to measure relative changes in caster, if you already have the numbers from an alignment shop as reference; that measurement is made using the differential pinion angle as a proxy for caster. I do Not believe you can accurately establish the base line yourself, unless you remove the hub assemblies from the axle ends.
If both axles are square under the Jeep (doubt 1/16 difference is meaningful error), tires good with equal pressure from side to side, brakes not dragging on one wheel, axle bearings good on all four corners, then pulling has to be front end alignment (including bent axle tube/inner "c's"). So start there.