which size tires

[yleefox]

I'm at the point where I need new tires. I currently have 31x10.5x15 ATs on my 83 CJ7 and they were fine when we lived in Central Florida and did nothing more than ride around in the woods, on flat logging roads with no rocks, just a little sand and mud at times.

Now I live in south Alabama where most of our trips will be similar to what I described above, however we will finally be close enough to take it to the southern Appalachian mountains, where we will most likely find more difficult trails. We are not going to be taking the tough trails, but I would like it to be able to handle the more moderate trails. I expect mud, sand, slippery clay, washouts and small rocks.

If I stick to the 31 sized tires, all I need to do is buy them, but if I go with 33x12.5 I will need to replace my wheels (wider), and install a 4 inch lift (BDS most likely).

I have 3.54 geared Dana 30 and AMC20 axles. I also have a T-18 , granny low first gear and a fresh AMC 304 with plenty of HP.


So, with all of this being said, should the 33s give me a substantial performance boost over the 31s? I'm planning on Mud tires this time instead of the ATs. This Jeep will see very little street use, mostly just getting us back and forth to the National Forest just a few miles away.

So what do you all think?

 

[Lumpy Grits]

How wide are your current rims?
Why not look at 32" tires?
I strongly suggest Moser 1-piece axles for the rear.
LG

 

[HackFabrication]

If I stick to the 31 sized tires, all I need to do is buy them, but if I go with 33x12.5 I will need to replace my wheels (wider), and install a 4 inch lift (BDS most likely).

I have 3.54 geared Dana 30 and AMC20 axles. I also have a T-18 , granny low first gear and a fresh AMC 304 with plenty of HP.

So what do you all think?

Economically: Go with a set of 32" tires with your stock suspension and avoid extreme articulation.

The 3.54 gears will be 'okay' with them. Not as nice as 3.73's, but manageable.

Bear in mind, that just because the company says it's a 32 (or 33, or 35) inch tire: It might not measure out to be that tall.

Trust me (and a few others): Swapping in larger tires creates a lot of issues that will need to be address. Suspension, driveline angles, caster, brakes, gearing, horsepower, are but a few of them. And 'issues' means $$$$.

Never forget: We won WWII with 'stock' Jeeps.

 

[yleefox]

LG

The wheels are the original 83 CJ7 rims, which are supposed to be 7 inches. Good suggestion on the Moser axles.

Hack

I'm somewhat aware of at least some of those issues you mentioned and I'm prepared to work them out if the extra width and roughly two inches of diameter are worth the effort. Since I only have experience with the 31x10.50x15s, I wonder if the additional tire width and height of the 33s, will make give the ole Cj a significant improvement in offroad abilities. If the improvement is only marginal, then I'm not going to the effort of going with the 33s. Frankly, I don't care about the "Looks" as apparently so many people do these days.

 

[Lumpy Grits]

You can run 7" wide with 33's.
I have for decades.
What type of diff carriers are you run'n? LSD, DL-what?

LG

 

[yleefox]

LG.

I thought 8" was the narrowest for a 12.5 tire, so thanks for the information. I haven't physically checked to see if those diffs are open or LS, but I will as soon as the front and rear cover gaskets arrive, so I can change the gear oil. Even if they are LS, with 256K on the clock, I would think they would be worn out.

I was going to run a lunch box locker in the front, but you all but talked me out of that in a reply to one of my other threads. I'd run a detroit in the front, if I wasn't concerned about having to set up the gears (something I haven't ever done before). I'm not sure what I would do about the rear, because I'm sure my better half would not want to listen to a bunch of Snap, Crackle, and Pop, when we're out riding. If I go with a diff that has to be set up, then I will definitely change the gearing too (probably 4.10).

Your comments?

 

[Lumpy Grits]

Go with 32's, and a good LSD front and rear.
Just stay away from OEM, TracLoc.
Call these guys for more info.
The first 2 LSD in the link are very good.
https://www.randysworldwide.com/pro...d+Slip+Differentials&parent-id=173&diffid=235

Of those 2-I would go with the True-Trac and Moser 1 piece axles in the rear.
They also have TT for the front.

LG

 

[jfmcj7]

Go with 32's, and a good LSD front and rear.
Just stay away from OEM, TracLoc.
Call these guys for more info.
The first 2 LSD in the link are very good.
https://www.randysworldwide.com/pro...d+Slip+Differentials&parent-id=173&diffid=235

Of those 2-I would go with the True-Trac and Moser 1 piece axles in the rear.
They also have TT for the front.

LG

Holy smokes. $740 for a LSD? For a $100 more one can have a selectable locker. Won't that be a better option? Just asking.

 

[jp360cj]

Holy smokes. $740 for a LSD? For a $100 more one can have a selectable locker. Won't that be a better option? Just asking.

Those prices look a bit high to me. You should be able to find a Trutrac for about $100 less (at least last time I looked). The AMC20 parts do tend to be a little more expensive than most Dana axles though.

 

[yleefox]

all get information, thanks to everyone!

 

[Lumpy Grits]

Holy smokes. $740 for a LSD? For a $100 more one can have a selectable locker. Won't that be a better option? Just asking.

They are American made, and I have never had any issue with all of the ones I've installed over the yrs.
They work very well in snow and on ice.
TT's are what I would run, if I didn't run front & rear DL's.
Respectfully,
LG

 

[lowcountry]

They are American made, and I have never had any issue with all of the ones I've installed over the yrs.
They work very well in snow and on ice.
TT's are what I would run, if I didn't run front & rear DL's.
Respectfully,
LG

Agreed. I run True Tracs on my 700+ hp camaro...