I am in the process of lifting my wifes 2000 Sahara TJ 4.0--A/T 3.25 inches with a SL and then if needed another 1.000" with a BL ... so I can put on 33" BF Goodrich A/T's.... ......... now heres the dilemma and questions.... I notice when I'm running down the highway at 60 MPH I am only running about 2050 RPMs/....yep thats all.. it does very well though and it now has 30.5/9.50 tires on it .... so I'm thinking it aint gonna like 33's as it is ... I checked the axle tags and sure enough they say 3.07 ......now heres the dilemma and questions... I was told a 3.73 or 4.10 would be the best ratio for all around driving with the 33" tire on the 4.0 engine ..with A/T ??? Its a mall crawler and just needs to run the blacktop and get good mileage with reasonable power .... Can I just replace the 3.07 gears with the new ratio gears or is there going to be a carrier mismatch or ???? please advise on this scenario .. I'm guessing i have the 30 in the front and 35 in the rear ....???thanks
Last edited by wheelie387a; 07-15-2013 at 07:57 PM..
didnt all saharas come with D44 rear? any ways i have a 2002 tj sport with 3.07 gearing and running 33 super swamper tires and its my daily, on 4th gear and at 100km/60mph in forth gear i run just under 2k rpm and the jeep still pulls on even road if i throw it in 5th rpms drop to 1300 to 1500 rpms and my speed holds on a straight away but the smallest incline the speeds start to drop but i downshift to 4th and smooth sailing, the only times i slap it in 3d gear is when im going on a round about that has a big incline thats about it.
oh the tires im running are 33 12.5 15 with a 10 inch wide tire and 3.5 inch lift but the off set on my tires are about 4 to 5 inch back spacing so i dont rub when i turn or anything
I think the Rubicons came with the D44 ,(not sure) but not this Sahara ... I checked the tag anyway to be sure and it said 3 07 in the numbering ..... and if I'm 2050 rpms now with the 30" tire (29 actually) , the 33 is gonna be how much lower rpm???? anyway I dont mind changing gear sets , but was wondering about different carriers for the 3.07 / 3.73-4.10 ? or if I can use the same ones.
Your RPMs will be 13.7% lower at any given speed with 33s and you current gears over your 29s (assuming those are the actual sizes of them).
The carrier break on the D30 is 3.73 and up and 3.55 and up for the D35. Since you have 3.07s you will need a new carrier front and rear since I don't believe anyone is making thick gears for either axle. They aren't all that expensive though.
X2 This setup will return everything back to a factory like setup as far as power and MPG's go. Be sure to change out the $40 speeogear in your transfer case to reflect the speed that you are driving. The different size tires and gear ratio will throw it off and you will think you are getting worse MPG's than you actually are.
Don't you have the axles mixed up (backwards) for the carrier break?...
Nope. Although I could see how some may misinterpret what I said.
D30 is 3.73 and up (numerically)
D35 is 3.55 and up (numerically)
OP: do have any junkyards locally that might have used TJ axles? If they do and they have some with the correct ratios, you may be able to save some money over putting new gears in the axles you currently have.