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Need some help/info fast. thanks :) 91 MJ


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Find a set of 4.10 axles regardless of the tire size. :D

 

I disagree. I've driven Pat's 87 on 4.10s with IIRC 31s, and for street driving it felt like too much gear. I think 3.73 would have been nicer.

I'll see your disagree, and I disagree with your disagree.

 

3.73 gears with 31" tires is EXACTLY the same overall final drive ratio (expressed as RPMs per MPH) as stock tires and 3.54 gears. But the tires are much bigger and heavier. 3.73 is a good ratio for 30s. 4.10's is perhaps optimum for 31s and okay for 32s, anything bigger needs 4.56 or 4.88.

 

Back to the original poster -- I would agree that 31x10.50s would be a better choice for you, and you can run them with no lift. (I'm currently running 31x10.50s on my '88 XJ, which has smaller rear wheel wells than the MJ.) However, if you MUST go to 33s, be very careful regarding width. Factory Jeep wheels have 5-1/4" backspacing. In the back, 31x10.50s end up very close to the inner fender and to the leaf springs. If you try to run tires any wider than 10.50, you will absolutely have to go to aftermarket rims that have less backspacing.

 

"Cool," you might say. "No problem."

 

Except that the vehicle has a front axle. In the front, 10.50 width tires on stock rims tuck up neatly inside the flares and sheet metal. Put the same tires on aftermarket rims with less backspacing, and suddenly when the suspension compresses the tires crash into the flares and sheet metal. Hilarity ensues.

 

It's not really a good idea to go bigger on tires than what you actually need. As with lifts and pretty much everything Jeep-related, cost increases exponentially with size. The higher cost of big tires is only the beginning.

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^ thats a good point. I was thinking 33x10.50 BFG KM2's on the stock TJ rims. But it may be better to just stay on 31's. So what year and vehicle type should I be looking for to score a non-vac HP 30 w/ 4:10's? a 4cyl TJ? I thought about an IFS toyota rear axle to get 4:10's...but they are only 58" wide WMS-WMS

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All TJs have low pinon front axles. But for what it's worth, on a 3" lift, a low pinion axle should work just fine. :thumbsup:

 

Look for XJ front axles. Being non-vac is overrated since it's easy to bypass the CAD.

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2wd and 4wd center consoles are the same, basically.

 

You're little coin holder will pop right out, and the 4wd shifter bezel will go in its place.

 

And not "any" 231.

 

You need a 23 spline. You can swap a 23 spline input into a 21 spline, however, if it comes down to that.

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right...23 spline which is 91+

 

All AX-15s will be 23 spline, and they started getting put in halfway through 89. If you end up using a mid 89-90 trans, you'll need a special pilot bushing, but a T-case from those years will work fine.

 

IIRC the AW-4 went to 23 spline in 90, so you could use one off of that too.

 

thoughts on running a toyota rear?

 

Personally, I wouldn't. Width isn't the same, and it's gonna be some work getting it in there. You'd better off finding an XJ axle and re-welding perches. Keep it Jeep.

 

Also, I wouldn't get too picky about your front axle. The CAD really isn't a problem, and some say the CAD housing is actually stronger than the non-CAD. You can easily lock it over, or pop a non-CAD shaft in later on.

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There are a bunch of members on here from the Charlotte area. Go to the wheeling section and to SE area and youll see whos around.

 

cool...maybe someone has a good deal on an ax15 for me. that is worrying me...

 

yeah I agree on the toy axle...its super strong though.

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