Advice please: '90 YJ Conversion

Tires that big on a Wrangler will require MAJOR suspension work and a lot of fender cutting. Even 35-37" tires take quite a bit of work. If you are a total newbie to lifts in general, this might not be a good undertaking as your first lift project.

That said, a spring over axle (SOA) conversion is the easiest way to get the lift you need, but there are drawbacks. You would probably need some lift built in to the springs in addition to the SOA conversion. SOA conversions also have the drawback of axle twist. My suggestion is that if you want to have this much lift is to Goggle SOA conversions and read up on them. There is quite a bit of info on the net.

Chris

Garrett wrote:

He will have doe very major issues. Beside clearance there will be spring wrap up as stated, (really needs a 4 link setup) a need for much larger/stronger drive axle assemblies (even D60's front and rear would be a bit light for this). Then there will be drive shaft angle problems and you will need axle ratios of at least 5.38 to 1 or deeper too. This is not to say it cannot be done but it is to say it will be no easy task

----------------- TheSnoMan.com

Agreed, not only will it take major suspension work, you will have to pretty much completely replace your driveline with (at minimum) 1-ton axles, heavy-duty transfer case/transmission, driveshafts, etc. I think you may have the Pugeot trans, it's not even adequate for a stock application, never mind 42's. You're talking about serious coin and serious work.

application, never

The BA 10/5 was used from 1987 to mid 89 when it was replaced by AX15. That aside the load on a tranny is determined by your effective final drive ratio more than tires alone because for example 30's with 3.31 gears would place more "strain" on tranny than 40's with 5.38's.

----------------- TheSnoMan.com

Do a spring over and put it on 33's. You'll love it and it won't break the bank like going to 42's. A wrangler on 42's is completely assinine. You can run 33's on your stock axles, but you cannot lock the rear.

To make your wrangler handle 32's is $6000. Minimum.

My best advice would be to get a dana 44/ford 8.8 or XJ 8.25 and put it in the rear, locked up with a detroit, 4.56 gears. Get 4.56 gears and a selectable locker for the front.

That traction and gear combination will turn 33's thru damn near anything without breaking the bank or a lot of parts.

Carl

Err to make your wrangler handle 42's, not 32's.

Carl

"This is not to say it cannot be done but it is to say it will be no easy task "

-I realize that it will not be easy. I dont expect this to be completed by tomorrow, it's something I plan to work on over a very long time period.

"A wrangler on 42's is completely assinine."

-I've already got 31"s on there, I don't really want to do a SOA conversion and only increase my tires by 2".

I made this page up a few months ago,

basically what i still need to know is,

-is there any kind of federal/state of CA law against having 40+ inch tires on a personal vehicle? or where would I find out?

- "you will have to pretty much completely replace your driveline with (at minimum) 1-ton axles, heavy-duty transfer case/transmission, driveshafts, etc." given that I have the A/X-15, do I still require a new transmission/ transfer case? how about motor?

Thanks!

Here's the site for California Law through 2006:

You are probably, though not necessarily, safe if you limit your search to the Vehicle Code, but the law is a funny thing, and I am not a lawyer.

Happy hunting.

Perfect! thanks!

You will need stronger axles but stock drive train can live IF you gear the axles properly. Biggest mistake people make is that they refuse to run 5.38 or deeper gears with big tires like this and this places a LOT of strain on drive train and this is where the need for HD trannies and Tcase is born because they try to use a big engine and tranny gears or Tcase gears to overcome the big tires and tall gears. Also kong as you take the time to properly gear it it will do surprizing well with stock engine but I cannot stress enough that gears will make you or break you on this project.

----------------- TheSnoMan.com

If that's what you want, go for it. Personally, I think a Wranlger on 42's just plain looks stupid. Too much tire. It's too tall and wide to really run any trails (at least where I'm from)

If you have the AX15 it might be OK, but you'll want a gear-driven t-case. Your best bet is to get two t-cases and run one in low all the time. Dana60

1 tons, disc brakes front and rear. I still reccomend the Detroit out back and a selectable up front.

The frame is going to need re-enforcement. I dont know at what points, but you will have to see where it flexes and eliminate it.

Anti-wrap bars will be a challenge because of the height. You don't want to limit articulation, but you don't want to allow wrap. I suppose you could mount them on the side of the frame after the centerpoint to add legnth, but make these strong as you'll then also be using them as a center-slider.

Custom over-the knuckle steering is a must. Please bear in mind that YJ's came stock with sway and trak bars, without these installed your vehicle may not pass inspection. You'll have to do a custom job on the trak bars.

Your stock steering box won't be able to turn the 42's, you'll need to upgrade it, though I'm not sure with what. A more powerful pump and stouter box are definately in order. The 4.2L will probably turn the tires if you have the right gearing (and the first t-case in low), but figure 45-55mph will be your limit, and 2-5mpg.

Most states have lift laws, and I do not think this will be street legal without a drop bumper and massive mud flaps. Plan on getting stopped a lot.

It's going to be a ton of work and $$ just to get it to reliably turn 42's. Even more on top of that to make it street legal.

Carl

By the way, there is nothing wrong with going SOA just to increase tire size by 2-4". It's not just about tire size, it's about added articulaton and clearance.

The above link is my old 89 YJ sprung over on 33's. On page one is the XJ on

31's.

Carl

this guy is just a moron who gets 1-2 MPG?Not being sarcastic, actually curious, lol.Thanks, Garrett

I could be wrong, but I am going to cry poser at that Jeep. First of all, if I took on a project like that, I would not do it with a 4cyl Jeep. They are a bit low on power as it is, and the power it takes just to turn the extra weight of the tires would make it worse, even with correct gearing.

The other thing is that if you look at that picture, he will not get much articulation out of that rig before he has tire to body interference, especially if the wheels aren't turned straight.

Again as someone else said, in many states that much lift would be illegal as well.

Chris

You will need stronger axles like these Rockwells, but at least you already have the leaf springs:

God Bless America, Bill O|||||||Omailto: snipped-for-privacy@aol.com

Almost certainly, if you are going to drive it places where you need 2.5 feet of clearance.

If your final drive ratio is low enough you should be OK but you won't be laying any rubber.

No, he's a poser who wants to look cool. That would actually make a great mud rig if it weren't for the four-cylinder.

Not saying he's a moron, but he will also get zero articulation. He would be a lot better off to run some 37's. Did you check out the pics in the link? What kind of wheeling do you want to do?

Carl