Need Help picking tire size.

Jeep Tech
1

I am hoping to get some help.
I have a 2005 TJ with a 4inch SkyJacker lift.
I am currently running Stock 17" 2013 Rubicon Wheels and Tires.
I would like to go to a 34 or 35. My question is width and rim size.
What is best for off road and on road.
I am looking at the Goodyear Fierce Tires.
Thanks in advance

2

Is your rear axle a Dana 35 or a Dana 44? If its a Dana 35 I’d be a little weary about going larger than 32-33.

Gearing is also a consideration. I’d recommend 4.56’s or 4.88’s for 35’s.

It looks like the Fierce M/T only comes in 3 sizes for 17" wheels:

265/70R17 (32x10.5x17)
285/70R17 (33x10.5x17)
35x12.5R17

3

Thanks eric I did not think of the gearing.
It has a dana 35 now. What do you think it would cost for new gearing to go with 34 or 35?
I would also be open to going with a 15" rim for more tire options but my parts dept had a listing for a fierce 34.4 x10.5
what do you think

4

I would not invest in gearing the D35.

It would still be drivable with stock gearing on the larger tires. 6th gear on a manual transmission would probably be useless and you lose some low range crawl capability.

Generally speaking you can expect $200 per gear set, $150 for install kit, and market rate for a professional gear setup is around $500. So $850 per axle. Throw in another $600-$1,000 per axle for lockers.

G2 sells a bolt-in Dana 44 rear axle with 4.56’s and the E-locker:

4wd.com/Jeep-Drivetrain-Jeep … D44TJ-E456

Its sells for $2,700 which is fairly reasonable (nothing about axles is cheap), especially considering that it includes that it includes a diff cover ($100), alloy axle shafts (another $300 or so), and beefier than factory mounting brackets.

15" wheels open the door to more tire options. Unfortunately, these days the wheel choices in 15" are rather limited. Mostly just steel and not many alloys.

5

for gears:
what gears do you have now?
is it an auto or manual?

8.8 out of an explorer is an other option, and usually come with disc brakes.

6

3.55 now and its an auto

7

Your defiantly going to want to regear. Autos typically like having a lower gear than a manual.

Probably want 4.88’s

Rim size should be around half the tire size.

8 out 10 wide rims are popular
8s make for skinny taller tires while 10s make for a wide short tire