Topic: Gear/Tire Question

[vinnyb3382]

I have a 98 Wrangler 2.5 SE with a 3spd auto and 3.73 gears. If I upgraded to 33*9.50 BFG AT's on black steelies, would I have to regear and/or upgrade my dana 35 axle as well? By the way, the only reason I want to go so narrow was to try avoiding a regear. My Jeep isn't my daily driver and rarely sees the highway. So what do you guys think?

[joe-joe]

If it's not a daily why worry about it? I would just go with a decnet 33x12.50 and not worry at all. You will still have more than enough power to wheel and even on the street you will still see 55-60 mph. The 33x10.50's would be ok but I would rather have a larger contact patch when I wheel. I drove my 99 TJ with a manual and 4.10's with 33's for about a year before I regeared up to 4.88's.

As for upgrading the axle, as long as you are easy on the gas pedal you should be fine. I upgraded my dana 35 shafts to Yukon "hardened" shafts which are supposed to be 30% stronger than a stock shaft and they were pretty cheap. I got a pair for $125 plus $10 to ship them. IF you are locked, I would reccomend adding the hardened shafts, if not, you should be ok.

[Jeffy]

The width of the tire has little bearing on gearing other then weight.  You're still dealing with the overall diameter of the tire being 32.5 for that 33" tire.

Optimal gearing would be easily done by swapping out the axles as a whole and replacing them with a 2.5L Manual's.  Then you'll be regeared properly and not have to pay for expensive services of an install.

[vinnyb3382]

Ok, thanks guys. I gotta think this over, its just that I have 30's on my Jeep now with a 3 inch lift and I really don't like all that gap.

[kamikaze124]

If your wanting to run over 60mph, I would regear it.. I would go ahead with 488's if you do decide to regear...  I have run the 456 gears in mine, and it was with 35" tires.. Jeep totally lost 5th gear.. Wish I would have went with the 488's instead.. My buddy did, and his jeep was great on and off the trail...  Both of the jeeps mention above have 4 cylinders in them...
Just a decision you will need to think about..
Good Luck..

[Jeffy]

He's got an auto, so no OD. 4.88's would limit his overall speed because his RPM's would be too high.

[kamikaze124]

If he is going with 33" tires, he should not be that far off of stock.. I to have an auto in mine...  I have spent the time and money to regear mine before to only wish I had went lower.. Because as you and I all know.. We all will usually go bigger sooner or later..  
Guess its gonna depend on how fast he wants to get to work, or how slow he wants to crawl..

[vinnyb3382]

So are you guys saying go with the 4.56 gears if I want to return to stock performance after the 33s are on?

[kamikaze124]

I don't know if 456 will put you at stock with 33's or not... But it will be real close.

[Jeffy]

Well, according to my chart 4.88's would get him back to stock, BUT this does not account for added weight and wind resistance.

And no I didn't bother to look at it before. :roll:    Actually thinking about it 5.13's would be best for a 2.5L on 33's so it makes sense to go with 4.88's.  Although I'm betting your RPM's would be pretty high at over 80mph.  But that's a good thing too.  Things get hairy at that speed.

[SMC4WD]

98 Wrangler?  I still didn't think 5.13's are available for stock axles...  We looked before (at Randy's R&P site) and I thought they were for a CJ.   :roll:

I am running 4.88's on my D30, the pinion is the size of a walnut (we'll close enough to it).  5.13 gears??  Gosh, the pinion would be the size of a pea.   :roll:

[Krod]

4.88 is as deep as you're going in a 30/35 combo.  To get the 5.13's you're going to need to snag a D44

[kamikaze124]

I am with the rest of the guys... I do not think they make the 513 for the dana 30 or 35.. Just go 488's and trust me... You will be happy..

[Jeffy]

Yes, the point of saying 5.13 is that you WILL have to change axles.  If you look at the Gearing chart I made up a while ago, you'll see that optimal gearing is 4.88:1.  

4.88's for a auto just seems awefully low.  I believe 4.88's will give a manual on 33's the correct speedometer reading but does not account for added weight.  So he could go with 4.56's and do the same.  He's be on the light side of optimal though.  Otherwise, he could go to 4.88's and gain some extra RPM's and torque.