lift question.....

[dunl]

I know, I know....but I'm not sure how to search for this. "lift" is too common, and it doesn't accept "33's"

 

So what lift is needed to run 33's? Specifically....33x12.5x16 Trxus M/T's?

[rtyler8140]

Depends on if you want to hack up your fenders or not. If you want to cut your fenders, you can do it with no lift (but thats a lot of fender to cut away). If you are not looking to cut the fenders, I'd say 6.5" of lift will be where you want to go to run 33's with no rubbing. Also with that tire size you need to get a rim with more backspacing so you don't rub your tires on the inside.

[Pete M]

don't forget gearing and axle upgrades

[Eagle]

So what lift is needed to run 33's? Specifically....33x12.5x16 Trxus M/T's?

Specifically -- on what rims, with what backspacing?

[dunl]

I'd love to hear suggestions for rims and backspacing myself. The only thing I have for backspacing right now (not installed), is a set of 2" wheel spacers I picked up one time in a fit of insanity. :no: :D

[Eagle]

I'd love to hear suggestions for rims and backspacing myself. The only thing I have for backspacing right now (not installed), is a set of 2" wheel spacers I picked up one time in a fit of insanity. :no: :D

You're missing the point, Mate. You asked how much lift is needed to run 33" tires. The answer may vary considerably depending on the backspacing of the rims you run, because how far out the tires extend (or don't extend) is going to affect where they rub, and how much they rub. If you don't have wheels, then your question cannot be answered.

[dunl]

I'd love to hear suggestions for rims and backspacing myself. The only thing I have for backspacing right now (not installed), is a set of 2" wheel spacers I picked up one time in a fit of insanity. :no: :D

You're missing the point, Mate. You asked how much lift is needed to run 33" tires. The answer may vary considerably depending on the backspacing of the rims you run, because how far out the tires extend (or don't extend) is going to affect where they rub, and how much they rub. If you don't have wheels, then your question cannot be answered.

 

I have a set of Ford 16" rims lined up, but not sure of any of the other aspects (guy works away a lot, and they're free....he's a jeep guy too, so correct bolt pattern). Tires are pretty cheap too, so figured I'd see if they might work. Jeep is currently sitting around 3" for lift.

 

What would you suggest for backspacing?

 

And for fun....would anyone here run 2" spacers? :brows:

[89eliminator]

2" spacer? please say coil and not wheel...

[dunl]

2" spacer? please say coil and not wheel...

:rotf:

 

Like I said....moment of insanity. :yes:

[Eagle]

Depending on the backspacing of the wheels, you might need a 2" spacer in the rear to keep the inside sidewall from rubbing on the inner wheelwell.

 

I question the wisdom of running 16" rims at all. With Ford rims, the center hole probably isn't correct for Jeep axles. If it's too small you have to grind it out, and if it's too large you lose the stability and support derived from Jeep's "hub centric" wheel design. Plus, for any comparable size, 16" tires are more expensive and harder to find than 15".

 

Your frames of reference:

 

Stock Jeep rimes are (mostly) 15" with 5-1/4" of backspacing. On those rims, both front and rear will accept 31x10.50-15 tires and require NO trimming of sheet metal or flares. The fronts rub on the lower control arms (slightly) at full steering lock, which is only a minor annoyance. In the rear, the inner sidewalls are very close to both the springs and the inner fenders. When I wheeled my '88 MJ with 31s on factory rims, after every trail ride there were black rubber marks inside the wheel wells where the top shoulders of the tires rubbed the fenders if the axle got "articulated."

 

That's for a 10-1/2" tire. A 12-1/2" tire extends 1" farther out, and 1" farther in. You could NOT run 12-1/2" tires in the rear on stock rims without a spacer at least 1" thick, and preferable 1-1/2 to 2 inches thick. A quality spacer machined from billet (not a cheap casting) would be fine -- but pricey. Wheels with significantly less backspacing would also solve the problem -- in the back. But ... if they are out far enough not to run the inner fenders ... they won't clear the flares and outer sheet metal.

 

But in the front, any tire wider than a 10-1/2" OR on a rim with less backspacing than factory will NOT tuck up inside the sheet metal. So once you either use aftermarket rims or go to tires larger than 10-1/2" wide, you either have to trim, or you need massive lift just to clear the sheet metal at rest. Worse, you also need to severely limit the amount the suspension can compress, because lift by itself doesn't stop the axle from moving up and sending the tire crashing into the fenders. You need to extend the bump stops -- the less you want to trim, the MORE you have to limit the suspension travel. That gets you on the street with sexy-looking big rubber, but it doesn't do squat for you on a trail.

 

Too many people, IMHO, decide that they NEED huge tires without giving any thought to how they plan to use the vehicle or what it takes to actually run those tires. The goal should always be to engineer the vehicle to run the smallest tire and the LEAST amount of lift necessary to accomplish your requirements. The cost of tires increases significantly with size. The cost of lifts increases exponentially with height (in other words, expect a 4" lift to cost four times as much as a 2" budget boost, not twice as much).

[dunl]

Lots to think about, and clearly laid out....thanks.

 

I've since found a set of 31 BFG MT's with rims for a good price....I'll be going with those. :)

 

I'm trying to decide if I should toss the spacers on for a picture, just for $#!&s and giggles. :D