wheels

[88wickedmj]

ive got a 88 mj with the chrysler 8.25 rearend and dana 30 out of a 98 cherokee i bought a set of 15x8 jegs baja 8's with a 3.75 backspace will these work on my mj or will they make my tires scrub on the frame

[88wickedmj]

i also have a 4.5 spring over lift from rustys offroad on it i was told that the wheels would make my tires scrub I'm going to be running 31/10.50/15 bfg mud terrains

[Eagle]

They won't rub the frame. Those wheels will extend OUT considerably more than stock. Your problems are going to be sheet metal and flares.

[mvusse]

With 4.5" lift front I think he'll be fine with 31s. As wide as the @$$ of our trucks is, they may actually still stuff in the rear.

[88wickedmj]

will me having the chrysler 8.25 out of the 98 cherokee make a difference cause right now i have the stock wheels and tires on it and i have maybe 2in between the rear frame rails and the tires :hmm:

[mvusse]

Any stock rear axle out of any year Cherokee is the exact same width as a stock Comanche rear axle.

 

Factory wheel backspacing is something like 5.25". Those 8" rims with 3.75" backspacing the inside will be 1.5" further away from the frame, the outside will be 2.5" further out than the outside of a stock 7" wheel.

[Eagle]

As mvusse noted, the width of a Cherokee axle is exactly the same as an MJ axle.

 

Stock Jeep rims are (usually) 15x7 with 5-1/4" backspacing. Running 31x10.50s on factory rims with no spacers, the inner sidewalls barely cleared the leaf springs in the rear but if I got the suspension at all crossed up off-road, I'd put rub marks on the inner fender panels above the axle.

 

Fast forward to the wheels you are considering. They are 15x8 with 3-3/4" backspacing. So the inner rim will be moved outboard by 1-1/2" compared to stock wheels. But we're not done yet. An 8" wheel is an inch wider than a 7" wheel (duh!), so the centerline is one-half inch farther away from each lip. We moved the inner lip out by 1-1/2" with the backspace change, but now add another half inch for the new centerline. So with the wheels you are considering, your tires will be riding 2 inches farther out than stock -- meaning with 31x10.50s if I had about 1/4" clearance to the leaf springs, you'll have about 2-1/4". Stock tires (225/75-15) are about 9" wide. You're looking at 10.50s, which are an inch and a half wider. That's 3/4 of an inch on each side of the centerline. So, overall, your new tires will have the outer sidewalls 2-3/4" farther outboard than stock.

 

I still think you may have problems hitting the flares and/or sheet metal, but I'm not sure.

[kawaboy13]

What is the approriate back spacing for an 11.5 inch wide on a 15 inch rim. I don't think I can put them on my stock Jeep aluminum wheels. I'm looking in to 32x11.5's but may get new wheels due to not being out far enough. I like them to stick out some also, but not too far.

[johnr]

Sooo with all that said ( all good points to think about) :ack: . if you 2 guys where about to buy a set of wheels and tires of the same size on a truck with 3.5 to 4" of lift what would your back space be if you really did not want to trim any sheet metal? if you could avoid it :idea:

[Eagle]

I ran 31x10.50s on factory rims with a 4" lift. The front tires rubbed the frame if I turned the steering wheel all the way to full lock (actually prevented getting to full lock), but there was no interference with the front or rear sheet metal or flares. But there are NO aftermarket rims with 5-1/4" backspacing. I think the most you can find is 4-3/4". I don't know if those will clear the front sheet metal and flares. Anything 4-1/2" or less will not clear without trimming -- unless you severely limit the suspension compression so the tire just can't get the the sheet metal.

[kawaboy13]

What is the stock backspacing? Wouldn't less back spacing stick your wheels out farther?

[mvusse]

To recap from earlier on the page, yes.

 

Stock backspacing is 5.25"

 

Less backspacing will make the wheels stick out more

 

This means that when the wheel travels up in the wheel well due to a bump in the road or whatever, the tire can contact the top of the wheel opening.

 

If this happens with enough force it can damage the fender flare and sheetmetal. If it pulls the flare off, the exposed metal edge can also cut into the tire.

 

That is one of the reasons you will need extended bump stops.

 

 

I think a 32x11.50 tire is probably a good match for 4.5" lift, but that does not mean you shouldn't extend your bump stops.

[kawaboy13]

But for a daily driver, this would look almost perfect with a 4.5 in back space I believe. I did not install 2 inch bump stops. We stuffed my tires and the springs are keeping them out of the flare?