Re-gearing: 4.0 with 33s

[MudderFudgingTJ]

New to the Jeep world and started off with a TJ. I am somewhat mechanically inclined so I have done all of the small upgrades myself.
However when it comes to the re-gearing I am not sure which would be ideal since I did lift and the bigger tires have made it super sluggish especially up-hill.

Currently on the research I have done the Front is Dana 30, and Rear is Dana 35. not sure on the ratio but everything is stock.
It is my DD, but also do some hunting in it which entails some moderate mudding and off-roading from time to time but still trust it on long highway drives.
I am willing to sacrifice the gas mileage to get it's power back haha. Not that it gets an amazing one now.

 

[mtngoattj]

4.56 gears would best for 33s


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[Hook_62]

X2. you can look hear also.
https://www.morris4x4center.com/jeep-tires/tire-gear-ratio-chart.htm

 

[Jerry Bransford]

X2, you want 4.56 gears for 33's if your TJ has the 5-speed transmission and 4.0L engine. Go with 4.88 if your engine is the 2.5L with 5-speed transmission.

 

[MudderFudgingTJ]

X2, you want 4.56 gears for 33's if your TJ has the 5-speed transmission and 4.0L engine. Go with 4.88 if your engine is the 2.5L with 5-speed transmission.

3-speed Auto

 

[Jerry Bransford]

3-speed Auto

No sad faces, I loved my 32RH and would love to have it back again. For the 32RH go with 4.10 gearing for 33's and you'll love the combination.

 

[jjvw]

X2. you can look hear also.
https://www.morris4x4center.com/jeep-tires/tire-gear-ratio-chart.htm

For others following along, that chart only begins to be useful for transmissions without an overdrive.

 

[Jerry Bransford]

For others following along, that chart only begins to be useful for transmissions without an overdrive.

True. It's a good chart for the 30RH and 32RH but its RPMs don't show the actual highway rpms you'd get with the AX-5, AX-15, NV3550, NSG370, or 42RLE... all of which have overdrives which significantly reduces the actual rpms you'd see on the highway. That type of chart has caused a lot of inexperienced people to misgear their Jeeps.

 

[Mr. Bills]

Use this gear calculator instead:

http://grimmjeeper.com/gears.html

It is not gospel, but it provides more useful information than a chart.

 

[jjvw]

Also, your tire size is not what is on the sidewall or listed on anyone's website. A quick and reasonably accurate method for measuring is to double the height of the hub center (or the center of the axle tube) from the ground.

 

[Hook_62]

True. It's a good chart for the 30RH and 32RH but its RPMs don't show the actual highway rpms you'd get with the AX-5, AX-15, NV3550, NSG370, or 42RLE... all of which have overdrives which significantly reduces the actual rpms you'd see on the highway. That type of chart has caused a lot of inexperienced people to misgear their Jeeps.

Right, that's because people don't read it. it literally states right above the chart:
"The below table can be used to get a rough idea on gear ratios. The colors represent ideal RPM's at highway speeds (65). These calculations are assuming a manual transmission with a 1:1 ratio. If you drive an automatic your RPMs will be slightly higher, and the opposite is true if you have overdrive (your RPMs will be slightly lower)."

 

[jjvw]

Right, that's because people don't read it. it literally states right above the chart:
"The below table can be used to get a rough idea on gear ratios. The colors represent ideal RPM's at highway speeds (65). These calculations are assuming a manual transmission with a 1:1 ratio. If you drive an automatic your RPMs will be slightly higher, and the opposite is true if you have overdrive (your RPMs will be slightly lower)."

If only there was a calculator that eliminated the guesswork needed to account for an OD gear that can be as low as .84 and as high as .69.

 

[Mr. Bills]

If only there was a calculator that eliminated the guesswork needed to account for an OD gear that can be as low as .84 and as high as .69.

That would be a useful tool. I wonder where one finds it?

 

[Hook_62]

If only there was a calculator that eliminated the guesswork needed to account for an OD gear that can be as low as .84 and as high as .69.

Yeah right. All I need is the 1:1 ratio, everything after that is a bonus for the highway and I really don't care what the precise RPM's are.

 

[jjvw]

Yeah right. All I need is the 1:1 ratio, everything after that is a bonus for the highway and I really don't care what the precise RPM's are.

Would you gear the 3 speed 32rh and the 4 speed 42rle the same?

 

[Chris]

Please fill out your profile, it helps us answer questions like this in the future

 

[MudderFudgingTJ]

No sad faces, I loved my 32RH and would love to have it back again. For the 32RH go with 4.10 gearing for 33's and you'll love the combination.

Awesome that is what people were telling me prior, that and the 3.73?
Any suggestions? If I get the parts myself. I wouldn't feel comfortable doing it myself but to atleast know the stuff I need and then find someone.
Do you know about how much it'll run?

 

[Hook_62]

Would you gear the 3 speed 32rh and the 4 speed 42rle the same?

Of course not. The 32rh doesn't have an overdrive, the 42rle does. just sayin, I don't need a chart/calculator to tell me what the rpm's will be at a given highway speed once I know what my 1:1 rpm is. All Transmissions have a 1:1 ratio (that I know of, could be wrong) overdrive is just a bonus gas saver at highway speeds. Just me, but I don't care what the final is as long as I have good power for what I'm doing offroad/highway.

 

[Serbonze]

I went from 3.73 to 4.10 in my TJ with the 32rh and 33s and I noticed an immediate difference. The 3.73 felt like I was towing a couple thousand pounds when trying to get out into traffic. I was very happy with change.

 

[Mr. Bills]

Awesome that is what people were telling me prior, that and the 3.73?
Any suggestions? If I get the parts myself. I wouldn't feel comfortable doing it myself but to atleast know the stuff I need and then find someone.
Do you know about how much it'll run?

Once you determine your desired gear ratio your priority should be to find the best jeep gear installer in your area and have that shop supply all of the parts. The better gear shops will refuse to install customer supplied parts. Even the shops that will install customer supplied parts will refuse to warranty the labor if it turns out the parts are defective or the cause of a failure.

Supplying your own parts is a false economy unless you are doing the work yourself, particularly since the U.S. Supreme Court in South Dakoka v. Wayfair, Inc. eliminated sales tax avoidance on Internet purchases .

As for cost, an average for parts and labor for a re-gear by a good shop is $1,600 +/-. How much the +/- works out to be will depend on the particular gears you buy, the shop labor rate, and a myriad of other factors.