JKOwners Forum banner

1 - 19 of 19 Posts

·
Registered
Joined
·
128 Posts
Discussion Starter #1
How can I find which gear ratio Im running??
I have a 2010 Unlimited Sport, automatic with the factory tow package.
 

·
Registered
Joined
·
3,401 Posts
How can I find which gear ratio Im running??
I have a 2010 Unlimited Sport, automatic with the factory tow package.
If you wanted to go OG, you could go to your Jeep, put the transfer case in neutral, jack up your rear axle, and spin the rear tires. Count the revolutions of the tire while the driveshaft makes one full revolution. You will get about 3.75 turns, or 3.73 to be exact.
 

·
Registered
Joined
·
128 Posts
Discussion Starter #4 (Edited)
The reason Im asking, is Im thinking of spooning on some 33's or 35's.....wanting to know how bad power, etc will be F'd up with my stock gear ratio. For some reason, I thought I had the 4:10...oh well.
 

·
Registered
Joined
·
532 Posts
I just went to 35"s and i have 3.73's the power is not too bad. i would do it again in a heartbeat.
 

·
Registered
Joined
·
1,886 Posts
If you wanted to go OG, you could go to your Jeep, put the transfer case in neutral, jack up your rear axle, and spin the rear tires. Count the revolutions of the tire while the driveshaft makes one full revolution. You will get about 3.75 turns, or 3.73 to be exact.
I think you have that backwards.
One turn of both tires would be 3.73 turns of the drive shaft.
 

·
Registered
Joined
·
32 Posts
I'm stuck here too...about to make a purchase and was wondering how the ride is with 35s and 3.73. Plan on regearing to 5.13 (automatic) but it's not cheaps and funds are going to be coming in slower with going to part time at work...
 

·
Registered
Joined
·
2,135 Posts
The reason Im asking, is Im thinking of spooning on some 33's or 35's.....wanting to know how bad power, etc will be F'd up with my stock gear ratio. For some reason, I thought I had the 4:10...oh well.
4.10's are Rubicons fyi
 

·
Registered
Joined
·
1,414 Posts
I think you have that backwards.
One turn of both tires would be 3.73 turns of the drive shaft.
2x... Definitely one tire rotation to (gear respectively) 3.73 DS rotations.

With an Auto I couldnt see 3.73's working with 35's. I have a standard and its still a bit of a dog with the 35's.
 

·
Registered
Joined
·
13,230 Posts
With an Auto I couldnt see 3.73's working with 35's. I have a standard and its still a bit of a dog with the 35's.
Yep, they would have to drive like total crap and truly be a "3spd"
 

·
Registered
Joined
·
532 Posts
Yep, they would have to drive like total crap and truly be a "3spd"
Haha. I was on the highway yesterday headed to the the lake and it was like a 3 speed lol. Unless I had just enough wind and a downhill grade lmao. I have 3.73 and I dont think Its too "doggy"


Sent via telepathy
 

·
Registered
Joined
·
1,287 Posts
If you can still read it, the gearing should be stamped on the stock differential cover. Or watch the ds rotations
 

·
Premium Member
Joined
·
641 Posts
I've got 4.10 and 35's & it's fine on the flat roads in FL, but off road it's still way to fast in 4lo when playing on the rocks. I'm going straight to 5.13...
 

·
Registered
Joined
·
22 Posts
I have 35's on my Jeep with 3.73's and an Automatic. It looks great but is gutless, and only getting about 14 MPG. If your driving a 2wd in an area with no hills I'd go for it, otherwise be prepared to change the gearing...
 

·
Registered
Joined
·
128 Posts
Discussion Starter #17
Well, after hearing all of this, I think I'll end up going with 33's instead. Love the look of 35's, but with the power loss, and price of a gear change, doesnt sound like its something Im ready for just yet.
 

·
Registered
Joined
·
2,286 Posts
Well... Can I ask what gears everyone suggest with 35's?
 

·
Registered
Joined
·
1 Posts
Gear Ratio

I have an 08 Rubicon Unlimited that I bought recently. The previous owner put 35's on it but didn't re-gear it from the stock 4.10's. Lets just say that the V6 is already a dog, but with the 35's it was unusable. The Rubi couldn't hold overdrive on flat highway surfaces. I ended up re-gearing it this week with 4.88's, and I Flashed the ECM with a Superchips Flashpaq. It is now better, more like stock, but still a dog. If I keep the rig I will seriously consider a Hemi swap in the future.
After gearing it I look to be getting about 1 to 2 miles per gallon better mileage. It is still pretty bad an average of about 13 mpg. I was afraid to gear it any lower, because I didn't want to loose my hwy speed. It is pulling around 2600 RPM at 70 MPH. This should be about ideal, anything lower and it would be more in the 3000 zone for the same speed. 2600 has good enough torque to keep the Rubi going in OD. Before the gearing it was running around 1800 at 70 MPH, not enough.
Make sure you put good gears in the Dana's and get it setup right. The spacers that come from Mopar are very thin, and are hard to get right. Go with a Spicer or Richmond Ring and pinion, much better than that foreign crap.
GOOD LUCK.
 
1 - 19 of 19 Posts
Top