Which Control Arm to Adjust for Caster?

[safarjohn]

Hey Guys,

I recently installed the Clayton 2.5 Overland Plus and I have both the upper and lower adjustable control arms. I need to make some adjustments to the caster. Should I adjust the upper control arms or the lower control arms to get the caster in spec?

Right now the Jeep tracks straight but has a lot of bump steer on the highway at speed and a bit of wondering. I already installed the Currectlync steering system with the Falcon 2.2 stabilizer so I’m hoping adjusting the control arms can help smooth it out. I’ve already had an alignment, just looking to better tune this for driving.

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[Randonexplosion]

Generally with link type suspensions the lower arms set the wheelbase and the upper arms adjust for caster and pinion angle. Im fairly new to the JT world but my previous experience has been that bumpsteer is cause by the trackbar and drag links not having the correct geometry. They should share the same angle and be as close to the same length as possible so that they travel at the same rate when the suspension compresses.

 

[DocMike]

I dialed mine in close then got it professionally aligned. Bought unlimited alignments from Goodyear tire for $150

 

[Randonexplosion]

I just installed my Clayton Ride Right 2.5 last night. I see you have a diesel, was your passenger upper frame bolt as miserable to access as it was for me?

 

[safarjohn]

I just installed my Clayton Ride Right 2.5 last night. I see you have a diesel, was your passenger upper frame bolt as miserable to access as it was for me?

Yes, I couldn’t get my torque wrench in there so I just used two box wrench’s connected to get it torqued to what felt based on the length of the wrenches combined.

 

[ShadowsPapa]

Hey Guys,

I recently installed the Clayton 2.5 Overland Plus and I have both the upper and lower adjustable control arms. I need to make some adjustments to the caster. Should I adjust the upper control arms or the lower control arms to get the caster in spec?

Right now the Jeep tracks straight but has a lot of bump steer on the highway at speed and a bit of wondering. I already installed the Currectlync steering system with the Falcon 2.2 stabilizer so I’m hoping adjusting the control arms can help smooth it out. I’ve already had an alignment, just looking to better tune this for driving.

Personally, I'd do both.
I'd shorten the top and lengthen the bottom to twist the axle and not just push out the bottom or pull back the top.

Pulling back the top alone pulls the axle back, pivoting on the lower.
Pushing forward on the bottom alone pushes the axle forward, pivoting on the top.

It reminds me of aligning an older Chevy car or 2wd truck from the 70s. If you only wanted to change caster and not camber, you needed to take out of one shim pack and add to the other, otherwise you chased your tail having to reset camber again.

 

[DocMike]

I removed the shims from a 51 Chevy 3100 in my youth. Learned really quick about caster and shim packs.

Personally, I'd do both.
I'd shorten the top and lengthen the bottom to twist the axle and not just push out the bottom or pull back the top.

Pulling back the top alone pulls the axle back, pivoting on the lower.
Pushing forward on the bottom alone pushes the axle forward, pivoting on the top.

It reminds me of aligning an older Chevy car or 2wd truck from the 70s. If you only wanted to change caster and not camber, you needed to take out of one shim pack and add to the other, otherwise you chased your tail having to reset camber again.

 

[kevman65]

If after you've messed with the UCA's and LCA's and you still have bump steer, you might want to look at track bar and drag link.

With the lift height putting those at a steeper angle it makes driving more harsh. You can do a drag link flip (high steer) and track bar relocate, gets those two items back to almost parallel with the axle.

 

[safarjohn]

I just measured the front axle side to side and it’s looks like my passenger side is half and inch less than driver….would making a 1/4 inch adjustment to the track bar to the passenger side make a difference?

 

[Randonexplosion]

I just measured the front axle side to side and it’s looks like my passenger side is half and inch less than driver….would making a 1/4 inch adjustment to the track bar to the passenger side make a difference?

If the difference is 1/2" then yes, lengthen your trackbar by 1/4" and it should be perfect.

 

[safarjohn]

Got the front adjusted, now going to readjust the rear. Hopefully this will help with some of the steering inputs from the road.

 

[safarjohn]

I adjusted the rear, had to put the rear bar all the way in to get it equal which was really only .25 of inch from what I had it from Clayton’s recommended measurement. Truck seems to drive better! I’ll give more feedback on the bumpsteer after driving it more.

 

[Clayton Off Road]

Use the front upper control arms to adjust caster, and front lowers to adjust wheelbase! Give us a call if you need any additional help or have any questions, always happy to help out with the install

 

[safarjohn]

Use the front upper control arms to adjust caster, and front lowers to adjust wheelbase! Give us a call if you need any additional help or have any questions, always happy to help out with the install

Thanks @Clayton Off Road! I’m waiting for the alignment shop to send me my specs so I can make minor adjustments. The lift is awesome!!! Quality stuff!

 

[USMC_1Wire6337]

I dialed mine in close then got it professionally aligned. Bought unlimited alignments from Goodyear tire for $150

Just be careful to keep an eye on tread wear. I got an alignment from Goodyear and it was within spec according to their machine and made no adjustments. I still had a pull to t he right and ended up with unbalanced wear. Talked to my trusted mechanic and he told me an interesting story that I believe but not 100% sure if it is true.

He used to do alignments, and when he purchased his equipment, the installer asked how accurate he wanted it to be. Apparently, the machine can be calibrated to be "within specs" on a quick pass alignment. This is shorter that a true and precise alignment by about 15-20 minutes. Most shops want to do them as fast as possible to get a better profit per charge. This can sometimes miss minor adjustments that would be caught with the better alignment.

Not saying your Goodyear will be bad, but just word of caution. Unlimited alignments is fine, but money saved may be eaten up by having to buy new tires sooner than necessary.

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