Back Spacing help

[Paddletrucker]

Well, after an absolutely brutal month of trucking so far, I've come to a couple of conclusions. 1. The only thing dumber than a truck driver is a truck owner. I'm both. My big truck has tried in every way to commit suicide this month. It's just been one of those months. Trucking would be a great gig if it wasn't for the customers, the driving, or the equipment! And 2. IT'S TIME TO GET BACK GOING ON MY JEEP!!!!!!!!!!!!!!!!!!!


I'd like to get the wheels and tires bought and in my possession before the lift goes on. That way, I KNOW I'll get what I want. My question is how much backspacing is needed?

I'm doing a 3" RC lift and may use spacers and the shackle relocation brackets to go up a touch more next year. I want to run 31"X10.5" tires. The Rough Country site says use 4.5" back spacing on the wheels. I was thinking 4" of back spacing, on 15 X 8 D-Windows. When I asked RC on the phone about going with 4", he said I needed to stay close to 4.5 so as not to rub anything.

Was he thinking my wheels would be closer with 4"? Am I thinking wrong? Would 4" be any problem? I'm thinking I'd like to go a little wide so that I can later go up in lift height and tire size. I thought the 4" would place the wheels further out and therefore be LESS prone to rub anything. Or should I just do what RC recommends on their site and do 4.5" of spacing?

Thanks guys. Looking forward to quitting buying expensive tractor/trailer parts and go back to buying XJ parts. It's a lot more fun.

Oh, and I'd be interested in seeing pics (of course, I'd like to see XJ pics!) of 4" and 4.5" spaced wheels for comparison, if 'ya got 'em.

[4.3LXJ]

Nate, the issue of back spacing is not much of an issue if you cut out your fenders. But if you don't. you need to keep near stock back spacing or you will rub when stuffed. Here is a pic to show you why.



This pic is with the same tire size you are planning on using. This is also with stock wheels with a spacer. Here is another



This one, the axle is not canted so much. As you can see, the top of the wheel will hit the top of the fender, even with the bump stop lowered in this case two inches. Your stock wheels are 7" wheels. So, with stock spacing you will move the outside of the tire out one inch. That will not leave you a lot to play with. So you need to keep the position of the tire as close as possible to stock. So, the bottom line is that with your new wheels at 4" back spacing and with 8" rims the outside of your tread will be even with the outside of the flare. You will still be able to stuff with a canted axle, but not with a straight up movement unless you move your bump stops down significantly. This will limit some of your total articulation. It is of course possible to move the bump stops down enough so that any 31" tire on any wheel can be used. But that is probably not what you want.

[Paddletrucker]

Oh, OK. That makes sense. I appreciate it.

I'm not wanting to trim the fenders...yet. :-)

I'll stick with the 4.5" recommended by Rough Country, then.

Good info, thanks.

Now I gotta go chain down a 53 foot load little flatbed utility trailers. YUCK. Then point 'er toward San Antonio.

Maybe I'll get to cruise the forum tomorrow.

[jeepxj95]

i use a stock rim with 31's. i have spacers on the front only so i dont rub on the LCA's. i did have them on the rear also but mine did steve's did so i took them off and i can stuff them a little further. but it would probly help if i had rear bump stops also lol oh well.