SOA vs SUA

[reptile610]

i thought i posted about this before, very surprised there isn't a stick about this.

pros v cons of each. thoughts for a "fun jeep" driven on the road, taken to the trail, beat on the trail, driven back home.

 

[Jimbos76cj]

Any way.. SUA look like it costs more on paper but its pretty easy to install. Gives you new spring to replace your old wore out ones and you can buy different amounts of lift From 2" to 4.5" Once you get into the 4" area you may need to get a CV shaft for the rear.

SOA looks cheap up front but here are the cons.

#1. with stock CJ springs your looking at least 5-6" of lift so you need to get a CV Shaft.
#2. With the springs on top of the axle you run into 2 steering problems
(a) The steering linkage will interfere with the spring pack.
(b) You will have a horrible angle on the linkage from the box to the knuckle even with a drop pitman arm causing alot of bump steer.

The way to properly fix the linkage problem will be to buy expensive high steer knuckle which then makes it more expensive then a SUA complete kit. Theres a few other issues tha I cant remember right now like having to weld spring perches onto your housing and axle tube but Im sure some one else will speak up about it. Unless they are tired of spewing the same info over and over again.

Most people who start off with a "cheap" SOA set up usually smarten up with age and return them back to SUA. How big of a tire are you going to? Before I get called a hypocrite My New project will be SOA but the axles are already set up for it with high steer knuckles and Hydro assist steering. Plus I plan on running 38.5" tires so I need all the clearance I can get.

 

[reptile610]

35-37" tires. Already going to do a 1" body lift plus looking at a few different companies that offer high fender kits. I wanna keep as lcg as possible

 

[Jimbos76cj]

Ive got 35" tires on a CJ with just a SUA lift. If your not afraid to cut the rear metal a little them you don't have to go crazy. 37's are alot to stuff with out stretching the front and rear. Being that it will be low COG you will need to do alot of opening up. The rear tire will probably hit the front of the rear wheel well.. you cant cut more then an inch forward on em because of the way the inner fenders fit. When I measured for the 38.5's with the axle in the sotck position it comes pretty close and will probably interfere with the front fenders. Im hoping to get the front half of my tub on it today and seeing how the 38's will look. If you measure the rear wheel well opening I think its only 32" wide. If I get my front clip on today Ill post some pics of it for ya.

 

[reptile610]

Thanks. So in ur opinion you'd say stick with 35s?

 

[Jimbos76cj]

Yeah.. especially if your gonna stick with the stock axles.. Mild abuse and 35's will destroy a stock CJ 20.. Im nervous about running the 38's on my Dana 44 's. I plan on running them until they bust then swap em for 1 tons, or my buddy is sitting on a set of rocks! maybe Ill talk him into selling them.

I know its hard to see from the pic but heres the CJ with 4" of lift and 35's


Look at how much room they take in the rear wheel well



I dont know how tall you are but Johns 5'2" this is again riding on 4" lift and 35's

 

[reptile610]

I'm 5'9" and I've had an lj with 35s before. Are these axles that crappy? I'm thinking about an axle swap but not sure to what yet. I wanna cut the rear to the inner well but I need to find a company that will offer a flare to fit because I like the look of flares.

 

[Incommando]

The stock Dana 30 front with 260-series axle u-joints and an unmodified AMC M20 rear are acceptable for stock with mild off-roading. For sure most people will tell you that 33's are about the biggest acceptable tire for those axles stock if you hit it even moderately hard off-road. Everyone and their brother will post up a " well my brother's cousin's CJ ran every obstacle in Moab on stock axles and 39.5's" but the you will find plenty of people making the 33" claim for them.

Your LJ had a better rear axle in factory configuration in the Dana 44 , but the front was still a low-pinion Dana 30 with larger 297 u-joints. Stronger than a CJ unit but not titan in the axle world. XJ/MJ/YJ axles with the larger 297 joints can get away with a little more but they are a stronger high pinion design. The issue with the Dana 30 is the tiny tiny ring & pinion and the weak axle tubes.

To run 35's most will suggest aftermarket axles for both ends with the 1-piece axle upgrade for the M20, trussing the out of both axles, and tacking the tubes of the M20 to the diff housing if the rear is still relatively straight. Many CJ's, even stock road jeeps, have a messed up M20 and folks don't know it until the try to mod it or the run into the common bearing/seal problems.

I went to a D60 front and shaved 14 bolt rear to run 38's. They may be slightly more than needed but with the 14 bolt shaved I still have more diff clearance than a Dana 44 on 35's and worrying about axle failures has now slipped way down the list on my off-radding concern chart.

Do a wider search than here and I think you will turn up tons of info to sort through before you make your decision. Keep in mind that as much as diameter matters the weight of the tire and wheel matter a ton, too. The last set of 285/75/r16's e-rated tires I had on steel rims where right at 120# each. I am afraid to weigh my 38x15.5x16.5's on 16.5x12 steel rims but they are no fun to put on the jeep sometimes...

Cutting the rear fender wheel and grafting on stock TJ flares will give you a big room boost in the rear.

 

[reptile610]

don't get me wrong i'd love to find some scout 44's to throw under this. another idea i was throwing around was finding a cj 44 wide track and a Dana 30 front wide track (even tho i have an 82 i have narrow track axles, think i have an 81 with an 82 body to be honest) upgrading them with chromoly shafts, better u joints, and lockers. but this all depends upon money and what i find. what im doing right now is putting 31's on it stock. going to do the lift as the very last thing.

 

[reptile610]

from what im understanding i could probably do the 1" body lift, hi-fender it, and a 2" SUA kit and i can run 35's easily and cheaply

 

[Jimbos76cj]

from what im understanding i could probably do the 1" body lift, hi-fender it, and a 2" SUA kit and i can run 35's easily and cheaply

You would need at least 4" of springs and 1" body lift. The high line shouldn't be needed for just 35's. Can you post a pic of the high fender your talking about?

 

[CJ007]

thoughts for a "fun jeep" driven on the road, taken to the trail, beat on the trail, driven back home.

This is what my goal was also. I wanted a capable CJ I could drive in town on occasion but didn't need it as a DD.

I broke lots of parts and upgraded as I went. You will find that things just keep breaking until you have chased down all the weak points and then you will rarely break and have lots of spare parts . Weight, torque, tire size, lift and gearing play a factor. If you are running fast and hard you will want to get the bigger axles and engine. If you put anything over 35's the same applies, even at 35's you will have to beef quite a bit to do moderate stuff without breaking. AIST helps too.

When I came to some of those same decisions regarding big axles and engines, I decided I wanted to keep mine as much like a CJ as I could and try to keep it light. I run moderate/lower end hardcore trails. I run 4 or less out of 5. Above 4 in AZ guarantee body damage and are typically buggy trails. I am ok with "body damage possible" .

I think I once said I tried to build my CJ as if it were a Rubicon CJ. I don't think it was well taken though

Here it is . If you scroll way down you can see the work I did to the 20.

http://www.jeep-cj.com/forums/f104/cj007s-1983-cj7-12863/

 

[reptile610]

either was going to do gen rights or metal cloaks.

Jeep CJ-5 & CJ-7 Body Armor ('72-'86)

 

[reptile610]

This is what my goal was also. I wanted a capable CJ I could drive in town on occasion but didn't need it as a DD.

thats exactly what i want. my lift will be done as the last thing. going to get it running right, upgrade steering, brakes, axles, armor, interior, then lift from what i hear my iron duke isn't going to like bigger tires anyways so it'll probably get swapped for a AMC 304 or 360