If your XJ was one with an MPFI 4.0 and an automatic, that's probably why there wasn't much felt difference. I doubt you will have the same results with a CJ.

 

Ya it was an automatic 4.0. So the upsizing to a 33 will more than likely be felt ??

 

I went from 33's down to 31's and it greatly improved drivability of my CJ. However, when I bough it I thought I was getting 3:31 gears, but when I broke the rear axle and actually checked I had 2:73 gears. I'm pretty sure that having those gears with 33's caused my clutch and transmission to explode. Not to mention the previous owner had just used taller shackles to make clearance for the tall tires, so it had a tendency to change lanes when I hit a pothole or bump.


I'll change the gear ratio some day, but right now reliability is my number one goal with my CJ. So the gear ratio swap can wait until several other things are done. I wouldn't go to 33's without knowing what ratio you have in your axles.

 

What R&P ratio are you run'n in that CJ?
Would really help if you would fill out your profile.
You may also want to look at 1 piece axles if you have the 20 rear.
LG

 

I went from 31 to 33 on my CJ5 but I have a V8. I had to do additional items to really dial it in correctly which included creating a new rear drive line with multiple ujoints, and obviously a lift kit with a drop pitman arm, added a sway bar, and I changed my rear axel to a d44 and gearing to 3.73. With all the correctly synced changes it drives and handles good but if you skip any of them you may have issues in handling, rubbing, or performance.

 

I went from the stock ~30" tires to 33" tires on my WK with a Hemi. I definitely noticed the drop in acceleration, especially the first 100 feet or so. I still have ridiculous power, but I've noticed it enough that I'm considering a ratio change (I'm underbudget on the build anyway, or I wouldn't even think about it).

You can compare (in your mind) the differences with the simple ratio of the diameters. 33/30=1.1, so you're about 10% different gearing. Roughly the same as going from 4.10 gears to 3.73.

My tread change was more dramatic to the driving "feel" than the diameter change I'm sure. I don't think I would have noticed a handling difference, once up to speed, if my tread patterns had been similar.

The look of the vehicle changed a lot. It went from pansy station wagon to looking like a meat eater. In my opinion, for both looks and performance, you need tires with the tread on the side. Even in town, it makes it so you don't give a crap where the curb is. One of my favorite things about a 4X4 is being able to run over curbs when I'm parking, or when I want to turn left where the traffic Nazis don't want me to.

As for which size to get, I'd get the biggest tire that an angle grinder will let me fit under the rig. If bigger isn't better, my apologies to the ladies.

 

For your sizes, going to a 32 would be a 3% change and going to a 33 would be a 6% change. Neither of those will drastically change anything, in my opinion.

Most axles don't even offer ratio changes less than 10%, so clearly axle manufacturers don't feel that changes under 10% are big enough to matter.

 

I realize I am in the minority here. I just removed 33x12.50 tires and a 4 inch lift from a 3.31 geared, T-177 CJ-5. Now has 31x10.50, stock length shackles, stock height springs and OEM pitman arm. The improvement in driveability is profound. The bump steer, wandering lane changes, rear vibration and sluggish acceleration are gone. The steering wheel actually returns to center after cornering, it responds when you hit the throttle and stops quicker when you hit the brakes. Well, maybe not as cool looking as the lifted 33 version. But it handles much better and is actually more fun to drive. Funny how age changes perspective.

 

It's important to know what you want the rig to do, and what your priority is. To some people, the added clearance is well worth the handling penalty, but if you're not using the clearance, and you are zipping around town, then a lift is not helping you. Besides, a stock CJ-5, skillfully driven, will go far more places than it looks like it would.

By the way, while I'm sure the lift was a big part of your handling change, I've had 12.5 and 10.5" width tires on the same rig, and the same diameter, and had a lot more steering problems with the wider tire.

I had a CJ-5 for years in the early 80s, and they are all over the road in stock form. It made my solid front axle 70 chevy feel like it drove itself.

 

I recently did a little experiment on my CJ7. The backstory is that my CJ has the inline 6 with the TF 999 automatic transmission running 3.31 gears and 33 inch tires. It's a dog and I wanted to see what it would be like with better gears of 4.10. I had a set of rims and tires that were 30.5 and I swapped them on the cj. What I noticed was better shifting, quicker response, and better braking. The difference between a 30.5 and a 33 in tire is quite substantial in weight rolling distance and size. You will notice the difference.

 

A few additional things to consider in your decision. For the BFG KO2 the weight of the 33s are 57 lb/tire. The same tire in the 31 is 43 lbs/tire. The rubber patch on the ground is 10.3 inches for the 33s and 8.8 inches for the 31s. Anyone need some "like new" BFG 33x12.50R15 KO2? Tread depth 14/32-15/32. Feel free to PM me.

 

I could use a set, mine are going on 10 years now...

 

I went from stock to 33's and it was a a pain with the T-150 but the t-177 and Dana 300 it works for me. I still have stock 3.54 gears.

Braking was fine even with the plow. But I did a complete brake overhaul with SS flex lines. Also went with soft pads as I didn't see the need for any high speed panic stops. It really only comes out to play in the snow.,..

 

a little more info on my jeep as requested. 4.3l gm crate motor(carbureted) with a 700r4 transmission. Axles are narrow track and said to be hardened(whatever tht means) current wheels are steel 15x7. Unsure of gear ratio. I ordered a set of America racing Baja 15x8 rims for next year. There's a lot of weight savings compared to the steel wheels. So I know if I keep the 31s or find a not so heavy 32 or 33 that'll help. I think I might be happy with a 31 on the new wheels. Stance will look better and honestly that's what I'm looking for the most along with drive and handle good. Axles and gear upgrades are wayyyyy down the road so might just be worth it to stick with he 31s. Thyre also almost brand new.

 

The main purpose of the jeep is to drive it. Mainly around town work and back and occasional dune trips. I'm a neat freak and like my stuff as nice as I can keep it. This jeep doesn't have any battle scars to justify making it into an off road monster lol. It drives great on the highway as of now and handles better then I thought it would. If I lose a little off the line performance by going to a 33 I'll be ok with that as long as the look of it is bad a$$ lol

 

This is a pertinent thread for me. I've been contemplating going to 31s from my current 33s to see if the handling improved. My CJ isn't all that bad but I am always at the ready for the Jeep to start wandering on the road. It's a minor problem but one that keeps me from letting my wife drive it. I'd love for her to enjoy the CJ as much as I do. I think I'll take a look at CL and see if someone has a set for sale.

 

As long as your jeep isn't sloppy and worn out, you will do fine with 33's. I have 3.31 gears and have been driving with 33x12.5 tires for 10 years. No wandering, accelerates, steers and stops fine. I have a 2" lift with Superlift springs. Just get the 33's.
4.2, T-177, PS, Trac-Loc

 

Another consideration is do you have power steering? I just returned from a three day trip in the mountains and my arms and shoulders are stiff and sore from manhandling 31s around the curves. Parking is a pain sometimes too. Suspect 33s would make it worse.

A visual trick is to paint the inside of the wheel wells semi gloss or satin black to reduce the contrast between the tire and Jeep.

 

I am running a 2.5" BDS lift with stock axles and 3.54 gears. Just moved from 31s to 33s and honestly have not noticed much difference. I will probably put in solid axles and good bump stops to keep the 33s out of the sheet metal. 33s don't fit the rear wheel well circumference. But the looks are there. Although not an ideal tire size for a lot of flex.

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I have power steering so I wnt need to worry about turning the bigger set up. I just dnt want the change in size to negatively affect a ton of stuff. It wnt be an off road monster by any means but i dnt need the tire cracking the fiberglass tub if it hits the wheel well lol. Speaking of that how durable is the fiberglass tub??