New to me tires & wheels have created problems

[Vali Jo]

Quick Background:
I have a '97 Sport with 2 1/2" RC lift. This lift has adjustable track bar, adjustable and stockier upper and lower control arms, and while I did use the provided shocks I recently upgraded to Bilstein shocks. Up until about a week ago I was running BFG KO2 33x15x10.5 .
For Christmas, my husband bought some (used) Dick Cepek rims and tires. The tires are 35x15x12.5 but I am not sure how to figure out the exact configuration of the rims. They look like the DC-2 Rims for reference but I don't know the depth and it appears that one rim is different than the others (based on the center cap)
My ball joints and tie-rod ends are less than 50K miles (recent replacement).
I just redid the brakes and regeared my axles from 3.07 to 3.73.
I do understand, bigger tire equals more weight and all that goes with it and will be looking for a beefier tie-rod as I am still running the stock (skinny) one.
The challenges are the following:

• I was already running my previous tires with spacers/adapters. (For simplicity I will refer to it as a spacer). I did not have vibration problems before.
• I am getting a vibration between 35 mph and 50 mph (death wobble style).
• Above 50 mph the big "wobble" goes away but something is still there (I can feel it but can't quite describe it).
• I believe that the tires need to be balanced (despite coming off of another TJ) however I don't think this is the underlying issue.

I don't want to just throw money at this and LOVE the look of the bigger tire but understand if I have to drop back down to a 33.
Could the tires be sitting out too far?
I have seen Mr.Blaine's explanation as to how to use a straightedge to measure the offset and once I have time to pull the tire off I will be measuring that. I do know that with the current set-up, they do not rub on any turn.

Ultimately, aside from checking the balance on the tires, where to start would be appreciated (along with any other guidance).

Thank you in advance!

 

[MtPockets]

I'm not an expert, but I do have a couple of suggestions.

First, since you got them used I would definately have the tires balanced just to have a good starting point.
Is that likely the problem? No, but it can exasperate other issues- especially with bigger tires on something light like a TJ.

Next, if you think one wheel is suspect I'd make sure that wheel is not on the steer axle.

I'd probably also make a note of which tire came off of which corner. If you continue having issues after the rebalance, swap them around to see if it changes.

 

[John Cooper]

Quick Background:
I have a '97 Sport with 2 1/2" RC lift. This lift has adjustable track bar, adjustable and stockier upper and lower control arms, and while I did use the provided shocks I recently upgraded to Bilstein shocks. Up until about a week ago I was running BFG KO2 33x15x10.5 .
For Christmas, my husband bought some (used) Dick Cepek rims and tires. The tires are 35x15x12.5 but I am not sure how to figure out the exact configuration of the rims. They look like the DC-2 Rims for reference but I don't know the depth and it appears that one rim is different than the others (based on the center cap)
My ball joints and tie-rod ends are less than 50K miles (recent replacement).
I just redid the brakes and regeared my axles from 3.07 to 3.73.
I do understand, bigger tire equals more weight and all that goes with it and will be looking for a beefier tie-rod as I am still running the stock (skinny) one.
The challenges are the following:

• I was already running my previous tires with spacers/adapters. (For simplicity I will refer to it as a spacer). I did not have vibration problems before.
• I am getting a vibration between 35 mph and 50 mph (death wobble style).
• Above 50 mph the big "wobble" goes away but something is still there (I can feel it but can't quite describe it).
• I believe that the tires need to be balanced (despite coming off of another TJ) however I don't think this is the underlying issue.

I don't want to just throw money at this and LOVE the look of the bigger tire but understand if I have to drop back down to a 33.
Could the tires be sitting out too far?
I have seen Mr.Blaine's explanation as to how to use a straightedge to measure the offset and once I have time to pull the tire off I will be measuring that. I do know that with the current set-up, they do not rub on any turn.

Ultimately, aside from checking the balance on the tires, where to start would be appreciated (along with any other guidance).

Thank you in advance!View attachment 662816View attachment 662817View attachment 662818

You're best bet is to sell them to me before you do more damage to your Jeep. ......

I would absolutely get them balanced, but understand you need lower gears for it to have better power.

 

[Ashim]

Sounds like a tire balance issue since you didn't have problems previously.

 

[TheBoogieman]

Balance them and check the DOT dates on the tires. They were discontinued quite a while ago.

 

[TheBoogieman]

Could the tires be sitting out too far?

Nah.

 

[MikekiM]

Tires aren't sticking out too far. Mine when I purchased it a few years ago....

I know it wasn't your question, but you went from 3.07 to 3.73 with the 33's and now are running 35's? I had 3.73's with 33's and an NV3550 (now an AX15) and it was an absolute dog. Kept the 33's and went to 4.56s.

 

[suicideking]

If you didn't have any noticeable wobble before, then it's likely the tires. I was having some wobble with my mostly worn GY MTR. Had them balanced, and still had issues. Fixed when I bought new tires. Went with Nitto trail grappler which have been much better on pavement.

Agree with @TheBoogieman to check the dates. I remember those wheels were popular around 2012 (when I got my first Jeep). So the tires could be older which may be a factor.

 

[OilSpot74]

So this might show my age, but if you want to know if your gearing is close I’ve always heard use the height of the tire times .12. So 35x.12 =4.2 if you are running 3.73s you are WAY under geared. I also agree with everything that was said in regards to balancing and checking the production dates to make sure all is safe. You may have also gone past that magical point where you may need a steering stabilizer. Just food for thought.