Alec S.

Hey all, new to the forum as I'm sure you all can see. I spend most of my time on the duramax forums but obviously I'm here for keep info.

This is is not a will x tires fit y jeep with z lift thread.
I can make phone calls and do more research on exactly what lift I want.

my question is every thread I read over the last few days says you cannot get away with tires over 33s and 35s are pushing it. Example say rear 8.25 front hp30 factory.

i have 2 sets of 37s laying around from my last truck and I'm looking to buy a jeep xj this time around for a hunting and play rig. That being said I don't rock climb I don't hit hard trails or off road parks. I like to go offroad and down some places a stock rig can't but I don't bounce and jump and get all twisted up by any means. I see rutted old logging roads and snow and maybe some mud but nothing I haven't seen a dozen half tons on 35s walk through. Are 37s just flat out not going to work for me? I don't want a rig I can't get in the snow and mud and hammer down (wheel spin not all twisted up) and constantly break stuff.

I had a 84 Toyota with dirty 30s and 37s long ago and never had issues but I really want a jeep this time around and I don't want to spend time and money swapping axles and a ton of gears and stuff to do "moderate" at best off roading. I want to lift trim tires steering and driveline etc basics and go.

So so is this something I can do since I'm not going "hard" off-roading so to speak? If not I will probably find a different candidate for a rig. Looking for a xj 4.0 manual most likely.

Sorry for for the long post guys I'm just not sure what everyone's doing to ruin so many axles on smaller tires

andrewmp6

Open diffs you might make it a while but its gonna be a mightmare on gas and a slow unless you re gear it to match the tire size.Wear and tear like brakes and the front unit bearings won't like the extra weight.And the stock steering might not like it either.

Martlor13

I don't think the xj is what you're looking for. You have to pay to play. Especially to run 37s.

Atmos

you can absolutely do it. however the biggest problems are going to be the things you don't think of such as bracing the frame rails. Factor into your budget a steering box brace and a track bar brace. Then you'll have to address your stopping power, you'll at minimum need an upgraded master cylinder and probably upgraded brakes on the axles too. Then the obvious stuff like power. As mentioned you'll want a regear which can get pricey but honestly that can come after the safety upgrade (brakes). Us off roaders are always worried about breaking axles when wheeling oversized tires, but even just on road there are major concerns with 37's. Like how fast you'll be burning through unit bearings


if you want to do it, go for it. But I'll say what I say to everyone. If you've got 37's laying around just post them up for trade and get 35's problem solved

Alec S.

Thank you all for your input I'll do some more looking around and see what I can come up with and let you know my final decision as well. Thanks to everyone's input!

MoparNJeep

Also depends on the brand of tires. If your 37s are Bfg Km2s they probably measure at 35 inches. My 35 km2s measured 33.5

andrewmp6

Your toyota had stronger axles then the xj does.It had full floaters front and back with a 8 inch ring gear and drop out 3rd members.The 4 cylinder had less power then a xjs 4.0.The toyota had at max 105hp and 140 foot pounds and 4.10 gears stock.The xj 4.0 the highest was 190hp and 225 foot pounds,And most auto 4.0 xjs are a 3.55 if you get the 4.0 with a stick its a 3.07 gear and both gears with a 37 inch tire will be a dog and probably never shift in to over drive on the highway.

Martlor13

the km2 is also heavier then most tires, even being slightly shorter.

investinwaffles

Yeah, at a minimum you will need tougher steering components and 100% need to brace and strengthen the steering box area.

If you are just running down the road, very very mild offroading, and some mud you probably will be OK

Or just sell the 37's and go with something more appropriate - 33's and XJ's go together like PB & J

Rogue4x4

I'll agree with that, for the most part...

OP, can you do it? Sure.

SHOULD you do it? No.

As stated, it will take a toll on your steering, and your brakes...and will be a dog on gas...and won't accelerate well...and yes it will play havoc with your unit bearings and u joints....

What hasn't been said here is how hard it's gonna make your engine and trans work...not too big a deal if you trailer it to your wheeling spots...but if you drive it there? FUGG-ED-A-BOW-TIT, LOL

Bottom line here is yes it can be done, but at a cost. Which could become a HUGE cost, eventually.

Pay now, pay later...your call. But know this, you will pay, one way or the other.

And, please, don't beat it down, decide to sell, and make it someone else's headache after you rip it up...unless you're straight up about it. There's a special place in hell for people like that, haha

Alec S.

Okay guys been doing some thinking I got the itch to just Dana 60 my obs f250 ford since I can run as big as I want and not worry but it's a big truck and won't get me any farther than my CCLB duramax will bring damn near the same length. But it's beatup already so won't make me sad.

However i cant shake the xj flexing around look and feel I had in my buddies. So I got to thinking about axles for an xj is there any easy swaps that will hold a 37? I should clarify my terrain is basically snow and maybe some mud and washed out hunting roads but absolutely no rocks. I will step down to 35s if need be but I will not go smaller due to the 3+ feet of snow we get in my cabin in winter.

so what would your guys axle swaps be that aren't ridiculous in cost? Hopefully there's something out there that can maybe even bolt in

andrewmp6

Only safe way to run 37s on a xj is axle swaps and really there is no easy or cheap way to do it.Its either you pay a lot for some custom 1 tons that bolt in from currie or east coast gear,Or you buy used ford dana 60 and a 1 ton rear aka a sterling or 14 bolt full floater then rebuild them cut off all the mounting tabs weld on new ones to the xjs specs then bolt them in.Or the cheaper easier way beef up your stock axles if you have a chrysler 8.25 in the rear if not swap that.Then run 35s on it and really not lose much ground clearance and a xj on 35s can be a monster off road.

Alec S.

saying I have a 8.25 rear and a hp 30 front what am I looking at for money to "beef" up stock axles to hold 35s and a lockers or is it still pushing it.

andrewmp6

depends the lockers you use and are you going normal trails are want a hardcore crawler

Alec S.

not sure on lockers really. But normal trails if that mainly snow in winter and just hunting/back roads in the woods nothing major by anymeans