Tire PSI question and floaty jeep

C

cryopanic

New member
Good afternoon everyone.
I wanted to get some takes on what might be going on with my '17 JKU. Currently, we have a full Clayton Offroad overlander+ 2.5" kit installed. Their kit comes with 100% adjustable everything (Upper/Lower control arms, track bars, etc) and Bilstine 5100. I recently upgraded to 35" STT Pros and it has been a driving nightmare. The jeep has been very "floaty/wondery". I took it to my local shop and they found the installer had all of the control arms at the wrong lengths giving it a right-side push (longer on the right side by almost 3") and causing the ball joints to go out. This was all corrected but he still does not feel "right" to me. The wife and I took a 3 hr trip last weekend and it was white knuckle the whole time. Jeep could not keep its lane, and when going uphill with cruise control it would pull hard left.

Reading through everything I could, I keep coming back to caster/pinon or tire pressure. Since the shop reset the caster to 4/5 degrees (per Clayton) I went ahead and chalk tested the tires yesterday. I had been running 28psi but doing the test, I came up with 24-25psi. This seems extremely low to me, but again I am running a lift that is meant for a full overland setup which we have not gotten to yet.

I am looking for thoughts on this, and to make sure I am not crazy.

Thanks
 
cryopanic said:
The shop did an alignment but they had to do it by hand as the local laser alignment shop was not available
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Doing it by hand is just fine as long as they added some toe in. You should verify you have Toe in before doing anything else. Just use a tape measure on the front and back of the tires. You should see a difference.
With my 35" I ran 1/8" toe in and 28psi.
 
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Currently dealing with a busted boot on my upper drag link end at the pitman arm. All the grease is out and it's totally worn. Drag link flops around and causes the steering to feel really loose over bumps. Check all your rod ends and track bar bushings.
 
DirtHeadDavis said:
Currently dealing with a busted boot on my upper drag link end at the pitman arm. All the grease is out and it's totally worn. Drag link flops around and causes the steering to feel really loose over bumps. Check all your rod ends and track bar bushings.
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The lift kit I bought came with Currie Tie rod and drag link. No matter what I have done the boots would not stay on them. I have since replaced the the tie rod with a steer smart one, but I wonder if the pitman arm side of the drag link is bad now
 
cryopanic said:
The lift kit I bought came with Currie Tie rod and drag link. No matter what I have done the boots would not stay on them. I have since replaced the the tie rod with a steer smart one, but I wonder if the pitman arm side of the drag link is bad now
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Don't think the Steer Smarts one will do you any better...
 
cryopanic said:
Good afternoon everyone.
I wanted to get some takes on what might be going on with my '17 JKU. Currently, we have a full Clayton Offroad overlander+ 2.5" kit installed. Their kit comes with 100% adjustable everything (Upper/Lower control arms, track bars, etc) and Bilstine 5100. I recently upgraded to 35" STT Pros and it has been a driving nightmare. The jeep has been very "floaty/wondery". I took it to my local shop and they found the installer had all of the control arms at the wrong lengths giving it a right-side push (longer on the right side by almost 3") and causing the ball joints to go out. This was all corrected but he still does not feel "right" to me. The wife and I took a 3 hr trip last weekend and it was white knuckle the whole time. Jeep could not keep its lane, and when going uphill with cruise control it would pull hard left.

Reading through everything I could, I keep coming back to caster/pinon or tire pressure. Since the shop reset the caster to 4/5 degrees (per Clayton) I went ahead and chalk tested the tires yesterday. I had been running 28psi but doing the test, I came up with 24-25psi. This seems extremely low to me, but again I am running a lift that is meant for a full overland setup which we have not gotten to yet.

I am looking for thoughts on this, and to make sure I am not crazy.

Thanks
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24-25 psi is fine but 28 would be better if only for tread wear and maybe better fuel economy.

+4 of caster is what comes from the factory and it should be fine but you can always up that to +6. That will help reduce flightiness but it will cause driveline vibrations if you have an aftermarket u-joint style double cardan driveshaft.

As mentioned I would check your toe to make sure that it's set correctly, about 1/16" toe in. The link posted will help you to figure that out.

Your drag link boot being torn will NOT cause flighty steering and replacing clearly is proof of that. So long as there is no shifting side to side or up and down, your TREs are fine. Rotation of the joints is totally normal.

With all that said and being that everything was set wrong initially, it is possible that one or more joints are now blown or worn out. At the very least, double check them as well as the torque on the bolts. IF the pitman arm was removed for any reason, check the nut to make sure it is on tight. Have someone turn the steering wheel a bit to the right and left and look at the nut - the BIG nut attached to the sector shaft. If you see ANY movement on the pitman arm, that nut will need to be tightened to torque spec. My guess is that it's fine though.
 
wayoflife said:
24-25 psi is fine but 28 would be better if only for tread wear and maybe better fuel economy.

+4 of caster is what comes from the factory and it should be fine but you can always up that to +6. That will help reduce flightiness but it will cause driveline vibrations if you have an aftermarket u-joint style double cardan driveshaft.

As mentioned I would check your toe to make sure that it's set correctly, about 1/16" toe in. The link posted will help you to figure that out.

Your drag link boot being torn will NOT cause flighty steering and replacing clearly is proof of that. So long as there is no shifting side to side or up and down, your TREs are fine. Rotation of the joints is totally normal.

With all that said and being that everything was set wrong initially, it is possible that one or more joints are now blown or worn out. At the very least, double check them as well as the torque on the bolts. IF the pitman arm was removed for any reason, check the nut to make sure it is on tight. Have someone turn the steering wheel a bit to the right and left and look at the nut - the BIG nut attached to the sector shaft. If you see ANY movement on the pitman arm, that nut will need to be tightened to torque spec. My guess is that it's fine though.
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Hmm, before I buy a new Drag Link end I'm gonna try this lol. I'm getting a shimmy over road imperfections - and road imperfections only. Trying to hunt it down, replaced the track bar with Synergy already, helped but still there...

Edit: Just had my coworker turn the wheel for me. Yeah the rod end is moving side to side 🤪
 
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DirtHeadDavis said:
Hmm, before I buy a new Drag Link end I'm gonna try this lol. I'm getting a shimmy over road imperfections - and road imperfections only. Trying to hunt it down, replaced the track bar with Synergy already, helped but still there...
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How many miles are on your Jeep? A lot of things can cause a shimmy on road imperfections. Could be something as simple as one bad shock - something that is totally possible on your Jeep. I would remove both front shocks and cycle them to full compression and extension. If only valves slowly, that could be your problem. Other wise, ball joints that are wearing out can cause what you're feeling as well.
 
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Having someone turn the steering wheel back and forth quickly (not far - 1/4 turn) is very helpful... Just put your hand on each rod end (drag link, track bar, tie rod) and if it’s bad you will feel a slight or major pop… then stare at your ball joints, pitman arm, track bar bolts. I can usually find the culprit right away.

I’ve found the track bar bolt at the frame gets loose faster than anything else. Re-Torque it because you may not notice it Visually.

Swapping in new rod ends is easy.. and will often make the Jeep feel new again. I’d say the draglink ends where out the fastest.

Check jamb nuts or collar bolts… make sure the rods aren’t spinning on the rod end threads.

Check the nuts on the tapered rod end bolts.. even though there is a cotter pin, it could be loose. Throw a wrench on it and try to tighten it a bit… you’ll know if its loose.

Then if all that is solid… its probably unit bearings or ball joints.

I also highly recommend marking paint on all the nuts, bolts and Jamb nuts… it makes a quick inspection easy while on the trail.

Just my thoughts... I’m not a pro, but thats the routine I generally go through.
 
DirtHeadDavis said:
Hmm, before I buy a new Drag Link end I'm gonna try this lol. I'm getting a shimmy over road imperfections - and road imperfections only. Trying to hunt it down, replaced the track bar with Synergy already, helped but still there...

Edit: Just had my coworker turn the wheel for me. Yeah the rod end is moving side to side 🤪
Click to expand...
wayoflife said:
How many miles are on your Jeep? A lot of things can cause a shimmy on road imperfections. Could be something as simple as one bad shock - something that is totally possible on your Jeep. I would remove both front shocks and cycle them to full compression and extension. If only valves slowly, that could be your problem. Other wise, ball joints that are wearing out can cause what you're feeling as well.
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It was that wash from HELL that helped it along.😖🤣 Going to be changing out ball joints soon myself. 50,000 miles with 35's and 37's it might be time.
 
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