Another 33" tire question. Sorry! (with 3.73 gears)

yeahsowhat · 01-23-2008, 12:57 PM

I have a super lift 4" lift and I am currently running 32" BFG MT tires. I would like to move up to 35's but have decided on 33x12.5R15 Baha Claws instead. I have checked my gears with the chart and it seems that I have 3.7's.

Currently I have lots of power with my 32"tires but my gas mileage around town is around 11-12mpg. I recently changed my exhaust to high flow and added a cool air intake and there was little change in my mpg. Sounds better though!

I have some money to re gear but I would rather spend it on some recovery gear. I would like to eventually go to a D44 and lock it. I want to wait until then to re gear and lock at the same time.

How much power will I loose going to 33's with 3.7's. How much worse will my gas mileage be?

Xlr8n · 01-23-2008, 01:42 PM

While the benefits of going from 32's to 33's won't be all that noticable on the trails, I did notice a change in going from 32's to 33's on the highway. And this is with 4.10's.

**TheBoogieman** · 01-23-2008, 01:43 PM

You have 3.73's and you won't notice any power loss from 32's to 33's.My brothers Willys edition runs great with 33's.He still uses 6th gear on the highway.

**mdm** · 01-23-2008, 01:54 PM

Quote:

Originally Posted by yeahsowhat

...I have checked my gears with the chart and it seems that I have 3.7's ...

What chart did you check that tells you that you have 3.73 gears?

You need to check the differentials to be sure. If you do in fact have 3.73 gears you will be downshifting to 4th on hills and in headwinds. If you have the luck of having a headwind when going up hill ...

If you have 3.07 gears you will find that 5th gear is just about useless and you will be downshifting out of 4th.

natedigity · 01-23-2008, 02:34 PM

First of all it is not as bad as people make it out to be. I have 3.07's and 33x10.50's. Just this weekend I towed a trailer from Seattle, Wa to Vancouver, Wa. I was in 5th gear except on hills, and when I wanted to pass people faster. I could maintain 70+ in 5th where there was not construction or traffic. I will regear in the future, but it is not so horrible I can't handle it. Basically your acceleration is hindered greatly, but you can still cruise. Besides I had to downshift from 5th in a headwind with 31's too, so what point does that make, jeeps are not very aerodynamic. Get the tires you want and see what it is like and then decide if you need to regear sooner. That was my plan and it is working fine. Nate.

yeahsowhat · 01-23-2008, 04:16 PM

Quote:

Originally Posted by mdm

What chart did you check that tells you that you have 3.73 gears?

You need to check the differentials to be sure. If you do in fact have 3.73 gears you will be downshifting to 4th on hills and in headwinds. If you have the luck of having a headwind when going up hill ...

If you have 3.07 gears you will find that 5th gear is just about useless and you will be downshifting out of 4th.

I checked a chart in 4wd hardware. At 65 mph w/ 32's etc...

Where do I look on the differentials?

Zlake · 01-23-2008, 04:18 PM

There is a tag on the differential cover. It is between 2 bolts on the left hand side (as you are facing the differential cover). There will be a bunch of numbers on 2 different lines.

I believe that it is on the second line and is the first set of numbers. Usually there is a big gap/space between the first number and the last two numbers.

**TheBoogieman** · 01-23-2008, 04:33 PM

Quote:

Originally Posted by natedigity

First of all it is not as bad as people make it out to be. I have 3.07's and 33x10.50's. Just this weekend I towed a trailer from Seattle, Wa to Vancouver, Wa. I was in 5th gear except on hills, and when I wanted to pass people faster. I could maintain 70+ in 5th where there was not construction or traffic. I will regear in the future, but it is not so horrible I can't handle it. Basically your acceleration is hindered greatly, but you can still cruise. Besides I had to downshift from 5th in a headwind with 31's too, so what point does that make, jeeps are not very aerodynamic. Get the tires you want and see what it is like and then decide if you need to regear sooner. That was my plan and it is working fine. Nate.

THANK YOU! I've been running 35's with 3.73 gears for quite a while and I can hit 90mph no problem.I use 4th gear until I get to 50mph then 5th all the way.The way I see it, it's like overdrive.I cruise at 75mph at 2000rpms.If I regear to 4.88's I'd run 3,000rpms.I've never had a vehicle that ran 3000rpms on the road and I don't even rev that high in low gears.Not to mention I get 20+ mpg highway.

yeahsowhat · 01-23-2008, 04:34 PM

it says 07 on the bottom line and the a gap and then a bunch of other numbers

does this mean that I have 3.07 gears? I followed the directions in the 4wd catalog. I purchased it used with the 32's on it already. Could the owner before me have changed them? If so, how do I know?

Urgh!

03silversport · 01-23-2008, 04:42 PM

Why don't you jack up the rear axle and have a friend spin the rear tire one full rotaton and count how many times the driveshaft turns in one tire rotation. If it turns 3x you have 3.07's, if it turns 3 3/4x you most likely have 3.73's.

kelly0724 · 01-23-2008, 04:59 PM

Quote:

Originally Posted by mdm

What chart did you check that tells you that you have 3.73 gears?

You need to check the differentials to be sure. If you do in fact have 3.73 gears you will be downshifting to 4th on hills and in headwinds. If you have the luck of having a headwind when going up hill ...

If you have 3.07 gears you will find that 5th gear is just about useless and you will be downshifting out of 4th.

YOU are exactly right!!

kizer · 01-23-2008, 05:07 PM

This tag.

That tag tells me my wife has 3.55's in her XJ.

**Terps1984** · 01-23-2008, 05:23 PM

Anyone running 33's on a 4 banger? I currently have 31's 4.10 gears and a 3" full traction lift.

Crashnburn80 · 01-23-2008, 05:29 PM

Quote:

Originally Posted by Terps1984

Anyone running 33's on a 4 banger? I currently have 31's 4.10 gears and a 3" full traction lift.

Your kinda thread jacking, but yes people run 33s on a 4cyl, if you do on the street you will want to regear to 4.88s.

jcssurf · 01-23-2008, 05:41 PM

Quote:

Originally Posted by Theboogieman

THANK YOU! I've been running 35's with 3.73 gears for quite a while and I can hit 90mph no problem.I use 4th gear until I get to 50mph then 5th all the way.The way I see it, it's like overdrive.I cruise at 75mph at 2000rpms.If I regear to 4.88's I'd run 3,000rpms.I've never had a vehicle that ran 3000rpms on the road and I don't even rev that high in low gears.Not to mention I get 20+ mpg highway.

Okay, I'm not calling you a liar, but there's something wrong with your calculating if you think you're getting 20+ mpg with 35's, 4" lift, a soft top, and 3.73 gears. 18 would be pushing it. Are you just going by the gas gauge?

I was born and raised in Cville, by the way. I was in Blacksburg for school and am in Richmond now, but I'm still home all the time. I saw your Jeep in Carrsbrook the last time I was home...it's sweet man.

You live so close to Freestate road...do you wheel there at all? We used to bog there all of the time in high school.

01-23-2008, 05:07 PM	#12
kizer Registered User Join Date: Dec 2003 Location: Marysville Wa. North of Seattle Posts: 1,601 Profile Gallery Classifieds My Jeeps	This tag. That tag tells me my wife has 3.55's in her XJ. __________________ Links4Jeeps.com 1600+ Write-ups, and more My Writeups \| My Heap