Tire scalloping / vibrations

[TJuser]

I've had an issue lately where I get fairly bad wheel vibrations, tire scalloping on the front, and shimmy at 75/80 kmh (used to be full dw but I replaced the lower track bar bushing). I tried taking off the front wheel weights and putting 10oz of balance beads in the front tires as I know m/ts don't hold their balance too great (cooper stt pro 35x12.50r15).

The vibes seem to come and go every 15 second or so and you can feel almost a hump at 35kmh. Is it just tire balance, or would bad shocks or alignment cause this?

 

[TheBoogieman]

Sounds like a balance issue. What tire pressure are you running? I did a DIY alignment 7 years ago and haven't touched it until I recently replaced my tie rod/drag link. Tires were Road Force balanced when I installed them 7 years ago. 30,000 miles on them now. Perfectly even tire wear, but small cracks from age (10 years old). I run 25 psi.

 

[TJuser]

Sounds like a balance issue. What tire pressure are you running? I did a DIY alignment 7 years ago and haven't touched it until I recently replaced my tie rod/drag link. Tires were Road Force balanced when I installed them 7 years ago. 30,000 miles on them now. Perfectly even tire wear, but small cracks from age (10 years old). I run 25 psi.
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I run 30-35 psi so I'm guessing it could help to air down a little?


The cupping is weird...the front of the tread blocks are way higher than the back as you can see in these pics

Compared to the rear which has even wear

 

[Artsifrtsi]

Do your dry steering checks, have balance checked, check ball joints, check your 'alignment', and check shocks.

 

[TJuser]

Do your dry steering checks, have balance checked, check ball joints, check your 'alignment', and check shocks.

I did the dry steer test...didn't notice any play other than the lower track bar bushing which I promptly replaced with moog... I did a brief alignment check a bit ago with a tape measure but I'll for sure check it again today. I was hoping the beads would save me from taking it in for balancing, but I guess I'll have to do that.

How would I check my shocks? Pop em out and cycle them?

 

[Artsifrtsi]

How would I check my shocks? Pop em out and cycle them?

Thats fairly easy, but not always easy to find a failure. On our TJ, the bad shocks just would not extend at all, or the same speed as the others. On the JT, there was really no way to tell, other than when different shocks were put in, the weird issues I had (diagonal bounce on full width bumps) went away... Sometimes the issue is easily observed, other times, not so much.

 

[TJuser]

Thats fairly easy, but not always easy to find a failure. On our TJ, the bad shocks just would not extend at all, or the same speed as the others. On the JT, there was really no way to tell, other than when different shocks were put in, the weird issues I had (diagonal bounce on full width bumps) went away... Sometimes the issue is easily observed, other times, not so much.

Ok, will have to do that.

Tire shop near me charges 10 bucks a tire to get them balanced, so I'll do that real soon

 

[Artsifrtsi]

Discount Tires, pay for the lifetime balance, and go in as often as you need to afterwards...

 

[TJuser]

Discount Tires, pay for the lifetime balance, and go in as often as you need to afterwards...

Do they have locations in canada? I don't think I have any near me

 

[Artsifrtsi]

Do they have locations in canada? I don't think I have any near me

ooo... did not see the Canada thing before...

 

[LONGJP2]

I run 30-35 psi so I'm guessing it could help to air down a little?

Yes, you should air down.

The cupping is weird...the front of the tread blocks are way higher than the back as you can see in these pics
Compared to the rear which has even wear

The tires aren't going to fix themselves and start rolling better.
At some point you will have to put the rear (good) tires in the front and hope that you've fixed the problem.

 

[DuckNut]

At Firestone they offer lifetime balance and alignment.

 

[TJuser]

Quick update....havent had the chance yet to balance the wheels but I was able to lift the front up this morning and check the wheel bearings and sure enough, front left had play...new one on the way and hoping to balance tomorrow

 

[glowell222]

Quick update....havent had the chance yet to balance the wheels but I was able to lift the front up this morning and check the wheel bearings and sure enough, front left had play...new one on the way and hoping to balance tomorrow

I would check the upper and lower ball joints as well.

 

[TJuser]

Got the front tires balanced....still have bad vibration...any ideas?

I would check the upper and lower ball joints as well.

How do you do that?

 

[LONGJP2]

How do you do that?

Bearings usually have play left to right.
Ball joints usually have play up & down.
https://wranglertjforum.com/threads/ball-joints-how-can-i-tell-if-they-are-bad.43301/

 

[glowell222]

Here's a pretty good video: Ball Joint Check

 

[TJuser]

Bearings usually have play left to right.
Ball joints usually have play up & down.
https://wranglertjforum.com/threads/ball-joints-how-can-i-tell-if-they-are-bad.43301/

Thanks!

Did the test, tiny bit of up and down play but nothing that looks like it's shot...still looks to be good

After the new moog bearing and balancing, it still vibrated and wobbled. I'm sitting here doing a rotation, turns out after asking the tire shop to remove the balance beads, he didnt...I have the beads and weights fighting each other