BMac329

Hey all,

Got a quick idea/ question...

I have an 01 WJ with the 4.0L and 3.55 gears. problem is that my cousin has the same as mine but a dana 44 and 3.73s, she gets better mpgs. Me being in auto school and through the axle and trans class, i got to thinking... would switching out gears from my 3.55s to 3.73s gelp my mpgs? I get about 13-14 city and my cousin gets 18 city. My WJ kicks down alot on the highway and I get a lot less than my cousin does on the highway. I know that the higher gears are suppose to lower the mpgs but the way I am thinking about it, my jeep wont kick down so uch to deliver more power to the wheel if I make them 3.73s, therefore increasing my mpgs and power.

Let me know what you think....

Another question, the Dana 30 front axle that all WJs came with, is it a High Pinion or Low Pinion for the gears? looking at getting a set of TJ gears that are HP 3.73s for the front.

Thanks alot in advance.

blackjack12982

All Grand Cherokee D30's (all front axles) are low pinion.

As for swapping the gears, unless you're lifted and running larger tires, the cost vs. gain is going to be very heavily skewed in the cost area. It's going to take a long time to regain the cost spent regearing your axles to possibly gain an MPG or two.

BMac329

Well, as of now I have a 2in spacer lift on the way and will have 31s coming after winter. I may just swap for another D30 and a rear D44 (both 3.73s)

blackjack12982

Unless they're free or very, very cheap you won't see the return on them for quite some time.

The only other slight bonus to that swap is you getting rid of your D35.

BMac329

yeah, I have found a V8 WJ in a salvage yard so I am going to look into it. They are asking $350 for the D30 and D44 both...

BMac329

Will ZJ axles bolt up to the WJ chassis?

blackjack12982

Yeah, if you want to cut all the brackets off, reweld ZJ brackets on, steering would be different, and deal with the length differences...







WJ bracket locations are different and the axles are longer on a WJ.