35s, 4.10s and a 6-speed...bad idea?

[highoctane]

Man looking back I hated my JK when I had the 35" Mud Grapplers, 18" Spyderlocks, and stock 4.10 gears. When I went to 37" MT/R Kevlars on Raceline Monster beadlocks it was practically undriveable IMHO, without revving it to the moon to keep it going. 5.13 gears was the best mod I did to my JK.

 

[greggnj]

Seen a few comments about rpm and drivability in sixth gear. I'm more concerned about getting it rolling in first, like at a stop sign/light on a steep grade. Any issues?? Don't want to destroy my clutch trying to pull out in traffic.

 

[Bigfoot]

Maybe I am missing something but as far as I understand this, a setup with 4.1 gears and 35" tires should lead to about the same ratio like a setup with 3.73 gears and 32" tires and a setup with 3.21 gears and 32" tires would be even worse than 35 / 4.1.

So the only bad thing for your clutch would be the extra weight of the new wheel and tire combination. But maybe that makes all the difference. I will have my 35" tires installed soon and find out about that.

 

[greggnj]

According to my calculations (which may be questionable...) starting in first gear with 35's is better than starting in 2nd with 32's. There's no accounting for weight or anything, just gearing. Of course, if I go with the Duratracs they're really closer to 34" I believe.

 

[Bigfoot]

According to Goodyear the Duratracs are 34.4" in diameter. I will probably have them installed next Saturday and I will measure the diameter in order to adjust the speedometer. I will let you know both what I will measure in the beginning and what I will really have to plug in so that the speedometer matches up again.

FYI the factory 32" BFG is programmed as a 30.75" tire and according to a GPS test that I did the other day my speedometer is accurate based on these 30.75".

 

[greggnj]

Thats interesting about the factory programming.

I'm interested to see what you think about the difference once you put them on.

 

[GetOut]

Thats interesting about the factory programming.

I'm interested to see what you think about the difference once you put them on.

In order to get an accurate speedo (verified by GPS) I measured the physical height of all 4 tires with all of the weight of the jk on them at the air pressure I use on the highway and averaged them. If you go with what the tire manufacturer states is the diameter of the tire it does not take into account the fact that weight and air pressure can change the diameter of a tire.

 

[First-one]

I just upgraded my tire's. I went with a 325/60/18 kumho kl78 a/t. I added 2" billet spacers and went with a 2.5" rough country budget lift. I've seen no difference in my speedometer reading, no roaring of the tires and no issue with shifting.

 

[Wartoy]

I have the sport gearing, 35's, and a 6 speed. ... works fine.