Rottwheeler

Runnning an 09 Rubicon Unlimited with a 6sp manual and about to do it's first lift 2 weeks before driving 14 hours to Moab. Two questions:

1) I've got 4:10s in the diffs with a manual tranny... are the 5:13s really necessary with 35"s?

2) Eventually I'm going to want 37's (this isn't my first Jeep :-). It appears that they will work with only a 3" lift as long as I am willing to mod my fenders... but with a 3" lift, modified fenders and an Unlimited with a manual trans, will I have to replace my drivelines?

A HEMI is in the plan for next year, so I don't want to replace my drivelines twice... which is why I may have to settle for 35"s for now. What do y'all think??? Thanks!

09rubicon

1: No. Since you have a manual the 4.10's are adequate. You will notice a lot less use of 6th gear, and a lack of power in 4hi, but it general it is very drivable with 35's.

I currently have 5.13's with 35's on my 2dr Rubi manual and actually feel a bit over geared (going to 37's soon so no worries!!).

2: If you truly are going with a Hemi then just wait on the 37's and gears. Unless you have the cash there is no use in throwing money away. With a 3" lift (assuming you trimmed your fenders) you could go with 37's and stock drivlines temporarily. The driveshafts probably would go on you within a few thousand miles if you flex alot, and you will need new driveshafts with the hemi IIRC. The Hemi also has gobs more torque and you may not want to change out those 4.10s until you see how it drives.

This would be my order of mods in your position.

1. Hemi
2. Lift w/ 37's
3. gears if neccassary

Piginajeep

no, not really..


You can wait until 37's for the 5.13's

GoodysGotaCuda

I'm pretty happy with my 4.10s/35s/6spd right now

Olean NY Jeeper

since I am considering doing with with 3.21's with 4.10s I would think you would be absolutely fine.

Piginajeep

it's going to be bad with 3.21's

Olean NY Jeeper

I have heard so many opinions on this. Some people say it is ok as long as you dont care about losing 6th gear completly, others make it sound like my jeep will cease to move. I am very conflicted on this.

Piginajeep

It'll move, but it wont win races or be great on long grades on the highway..


If its not in the budget for gears, just use more throttle and down shift

jkbluebeast

yeah 3.21 are not good. I run those with 33s and now power in 6th little to none is 5th. In town driving is fine but high way driving sucks I have to stay mostly in 4th gear.

Olean NY Jeeper

thats sort of what I was thinking, I may compromise and go with the Goodyear 305/70-17 instead, they are 34's. I want to do my rear driveshaft and adjustable control arms before re-gearing and I am on a very tight budget since my student loan payments are 1200 bucks a month.