95 YJ I6 Gearing

[JeepzRule]

Currently running original 3.07's with 33" tires. All my math calculations are telling me to go with 3.73's, but I have an opportunity to do a disc/drum conversion and upgrade to 3.55's. I know I'll have an improvement over the 3.07's however my formula shows I'll reach original power band placement with 3.73's. I know there are plenty out there that have done this so please advise........ Thnx!

 

[Steven Gable]

Not worth the effort for minimal gear change. You can get a stock ford 8.8 from a '96-2001 explorer with disc brakes and 4.10 gears for around $200. Stronger than a Dana 44 just need new spring perches and swap right in. Then you will need to regear the front to match, but you would have to do that anyway. Plus the 8.8 will handle much bigger tires in the future should you choose. I wouldn't go any bigger on a Dana 35. My thoughts. Good luck.

 

[superj]

that will probably be what everyone says as it is what i have read over and over.

i would go 4.10 is i was running 33's.

 

[Bounty__Hunter]

If your calculations and the ratio charts recommend 3.73 to get your RPM's back to stock, then I recommend 4.10 gears. The 3.73 would account for the larger rolling diameter but not the added rotational mass, always better to go a tad lower (numerically higher) to make the swap worthwhile and improve performance.

 

[JeepzRule]

Thanks everyone. This is a manual and not being used off-road. Is the 4.10 still the best option. Again thank you.....

 

[Steven Gable]

I still say go with 4.10. You will notice a big difference on the highway. Otherwise, your 5th gear will probably be worthless.

 

[phall92139]

How would you describe your rig's performance right now with the 33's and 3.07 gears? I would think that it pulls like a dog off the line, once up to speed it rolls down the highway like a bat out of hell but dogs out on long grades. You just can't much low end torque available and none at highway speeds. If that's okay, you're good with the performance and mileage then 3.73s are your gears. Just not worth the time, money or effort to go from 3.07s to 3.55s.

Bounty_Hunter hit the head on the nail though. Just getting the rev's back to the original range doesn't take into account real life factors like, as he said, added rotational mass of larger tires and wheels or additional weight gains from stuff like bumpers, skids, winches, roll bars, fat girlfriends, etc., etc. If you going to spend the money, might as well make it worth while. I vote for 4.10:1 gears.

 

[JeepzRule]

Thanks everyone! What a great way to help each other out. I appreciate everyone's time.......Sean

 

[jfrabat]

Bounty_Hunter hit the head on the nail though. Just getting the rev's back to the original range doesn't take into account real life factors like, as he said, added rotational mass of larger tires and wheels or additional weight gains from stuff like bumpers, skids, winches, roll bars, fat girlfriends, etc., etc. If you going to spend the money, might as well make it worth while. I vote for 4.10:1 gears.

Also does not account for the worsened aerodynamics... Lifted jeep with bigger and fatter tires at speed has A LOT more air resistance to overcome, and that is not considered in the equation. I also vote for 4.10 if you plan on driving it on the highway.