If I change the rear differential gear ratio, do I also need to change the front transfer case or differential for them to match?

Asked by Aug 21, 2007 at 01:11 PM about the 1999 Jeep Wrangler Sport

Question type: Car Customization

My son's Jeep has a low rear-end gearing. I haven't investigated it thoroughly, but it seems to be set more for rock crawling than anything. I'd like to give him some street performance and still have a little "off roading" capabilities, for sand and mud.

If I change the ratio of rear end, do I have to change something in the front end to match the drive ratios between the 2 axles?

Corey

9 Answers

5,195

I don't see why you shouldn't have to. The fronts and rears kind of like to go the same speed...

3 of 3 people found this helpful.

That was my thought, but being a 4wd newbie, thought I'd ask for some experienced advice.

25

YES you have to change them, or else you will screw up your t-case bad. my friend got a whole new axle off some one instead of re gearing it, it was cheaper. he has to get gears to match his ford 8.8 in rear

1 of 1 people found this helpful.
8,525

Terrence would be correct on that one. On most 4wd vehicles they advise replace 4 tires at a time for the same reason...(Different tread wear will result in a minute change in final drive ratio)

35

Both diffs have to match, I know of a chart, i think its in the Jeep owners Bible, tells best gear ratio according to tire size. you are best off leaving it stock for "STREET Performance" ( =P )

1 of 1 people found this helpful.
35

OMGawd! this is old! aug 2007 =P

170

if you do not change them both and make them the same ratio the jeep prob wont even move or the axle or t-cace will destroy itself

1 of 1 people found this helpful.
10

By reading these posts it seems that it might be eaiser to swap the transmission out (4spd to 5spd) to gain the highway milage and still keep a bit of the "off road" - Am I right in my thinking there??

1 of 1 people found this helpful.
10

Can I put a complete rear end housing from a 1990 jeep cherokee under a 1994 jeep wrangler yj

1 of 1 people found this helpful.

Your Answer

Wrangler

Looking for a Used Wrangler in your area?

CarGurus has 16,159 nationwide Wrangler listings starting at $2,500.

ZIP:

Jeep Wrangler Experts

  • #1
    tennisshoes
    Reputation
    410
  • #1
    Tom Demyan
    Reputation
    410
  • #3
    Mathew Wooldridge
    Reputation
    350
View All

Related Models For Sale

Used Jeep Grand Cherokee
883 Great Deals out of 70,104 listings starting at $1,045
Used Jeep Cherokee
349 Great Deals out of 46,186 listings starting at $2,795
Used Ford F-150
2,280 Great Deals out of 181,556 listings starting at $1,000
Used Ford Mustang
692 Great Deals out of 38,314 listings starting at $895
Used Toyota Tacoma
590 Great Deals out of 42,442 listings starting at $1,995
Used Chevrolet Silverado 1500
2,107 Great Deals out of 166,962 listings starting at $1,498
Used Chevrolet Camaro
404 Great Deals out of 30,571 listings starting at $3,550
Used Toyota 4Runner
283 Great Deals out of 21,489 listings starting at $1,700
Used Chevrolet Corvette
278 Great Deals out of 20,708 listings starting at $2,990

Used Cars For Sale

2017 Jeep Wrangler Sport For Sale
3,686 listings starting at $23,569
2016 Jeep Wrangler Sport For Sale
3 Great Deals out of 420 listings starting at $22,995
2015 Jeep Wrangler Sport For Sale
23 Great Deals out of 578 listings starting at $19,430
2014 Jeep Wrangler Sport For Sale
15 Great Deals out of 427 listings starting at $18,938
2013 Jeep Wrangler Sport For Sale
17 Great Deals out of 425 listings starting at $16,495

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.