2004 Sport 5-speed manual with 34” tires. Hasn’t seen 5th gear in a decade, pretty sure ratio is 3.07. Poser city Jeep so no need for a trail solution. Thinking ~3.7 would be a better fit. What are my upgrade options? I generally prefer OEM bin so do I look for Rubi diff and axles? Do I need axels? Pretty much a diy guy but not interested in rebuilding diff. What swap in solution do you recommend?
Lower Final Drive Options
- Thread starter Hit_Apex
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5.13 for the 5 speed pushing 34" tires gets you to about 3k rpm at 75mph. That is what you want. Quit arguing.
Yes you do.
Understand that if you want Rubicon axles, those were geared to 4.10 for a 31" tire. Your instinct of ~3.7 to push a 34" tire is already wrong.
Understand that if you want Rubicon axles, those were geared to 4.10 for a 31" tire. Your instinct of ~3.7 to push a 34" tire is already wrong.
We don't regear for a trail solution. We regear for a street solution.
^ this is the way
You believe you don't but you're wrong and that's okay. You don't know what you don't know.
I don't know what it takes to hyper mile a TJ on 34s. What I do know a bit about is what it takes to make a TJ get out of it's own way on the highway and make it fun to drive. If you want some of that from axle gearing, quit arguing.
If you want a swap in solution drop to stock tire size.
Be warned my AX-15 ran to 3rd with 3.07s and 33s installed by my PO for who knows how long. When I regeared to 4.88s (should have done 5.13s) I finally was able to use 4th and 5th. Both started howling a year later.
-Mac
Be warned my AX-15 ran to 3rd with 3.07s and 33s installed by my PO for who knows how long. When I regeared to 4.88s (should have done 5.13s) I finally was able to use 4th and 5th. Both started howling a year later.
-Mac
The bearings on that rail hadn't been used much if ever for a long time. By the time I started using them again they didn't last long.
All speculation. I replaced the AX-15.
-Mac
I recently got 4.88s on jeep with the nsg370.. and feel i am hearing a howling sound during longer drives. your post got me thinking.
If you lived with it for 10 years, why change it now?
30" tires.
You make a good point but no desire to downsize now
Thanks for your expertise and bearing with me as I learn this stuff. I confirmed my TJ 6MT has Dana 30 front and Dana 44 rear with 3.73 gears. This is probably why 4th is pretty good on the highway. 5th effective only on the flats or downhill. I am between 4.88 and 5.13 but the consensus here is the latter. If I do go the regear path should I consider Dana 44 swap up front?