Proper Backspacing

Hey guys,

I'm a CJ guy that's new to XJ's. I've got a 92 XJ that I'm lifting with DPG's 3.5" Hybrid Kit. I'm going to be putting 33x12.5 Goodyear MT/R's under it and some black rock crawler steel wheels. Obviously, I'll be doing some trimming. I'm wondering what backspacing is best on XJ's for clearance of front end parts. Where exactly is backspacing measured from?

Any help would be greatly appreciated. TIA!

CJHVN said:

Hey guys,

I'm a CJ guy that's new to XJ's. I've got a 92 XJ that I'm lifting with DPG's 3.5" Hybrid Kit. I'm going to be putting 33x12.5 Goodyear MT/R's under it and some black rock crawler steel wheels. Obviously, I'll be doing some trimming. I'm wondering what backspacing is best on XJ's for clearance of front end parts. Where exactly is backspacing measured from?

Any help would be greatly appreciated. TIA!

Click to expand...

I might be wrong but your choices are limited on the Black RK. I run 3.75 on 35's.

I guess I know how to measure the backspacing, I'm just wondering how critical backspacing is on XJ's. With 12.5 tires, I'm thinking that I should have the least amount to backspacing possible to keep from hitting control arms, etc.

What would you guys that are running similar set ups suggest?

thanks again

Stock XJ rims have 5-1/4" backspacing. 235/75R15s clear everything. 30x9.50R15s (on stock rims) often rub slightly on the lower control arms. 31x10.50R15s (on stock rims) always rub on the lower control arms.

You're talking about a tire that's 3" wider than a 30x9.50. That effectively adds 1-1/2" to the TIRE backspacing, so you need to reduce wheel backspacing by at least that much. So about 3.75" backspacing should do it. (As already posted, but this might help you to understand why.)

I just put some 33x12.5 GY MT/Rs on some 4 inch backspaced wheels and thy rub very little on the LCAs. So, you can either run 3.75 BS or run 4 BS and adjust your steer stops a little.

4" or less is better. That's what I was looking for! Thanks guys!