How much difference would I see going from 4.56 to 4.88 or 5.13?

I've got an XJ currently running 5.5" lift, 33" tires with SYE, lots of armor, auto trans, and 4.56 gears.

I wish tthe gears were deeper.

I almost never drive this jeep over 60 MPH and wouldn't really have a problem limiting it to 50-55mph in trade for more low end power. It's just a trail rig.


How much difference would I see going from 4.56 to 4.88? What about 4.56 to 5.13?


Thanks!

A rough estimation would be 200-250 rpms per ratio. Roughly

It will help with what you want, A Big difference going from 4.56 to 5.13.
But I would not waste my money regearing from 4.56 to 4.88, IN MY OPINION it is not worth the investment, Not a big enough return for the outlay of cash!

90Pioneer said:

I've got an XJ currently running 5.5" lift, 33" tires with SYE, lots of armor, auto trans, and 4.56 gears.

I wish tthe gears were deeper.

I almost never drive this jeep over 60 MPH and wouldn't really have a problem limiting it to 50-55mph in trade for more low end power. It's just a trail rig.


How much difference would I see going from 4.56 to 4.88? What about 4.56 to 5.13?


Thanks!

Click to expand...

If you were doing any serious offroading or desert racing wouldn't you know the answer to this?

Built2Flex said:

If you were doing any serious offroading or desert racing wouldn't you know the answer to this?

Click to expand...

Do you?

Gears and install is more than half way to a Tera 4 low kit or a down payment on a used 241or.

What is the strength difference between the 4.56 and 4.88? The 4.88 has a tiny little pinion gear it seems

Yea i would not go too steep on a D30 because like Chpmnsws6 posted above the Pinion gear is small.

I went from 4.56 to 5.38s and just said f-it and made a real change in gears...
then the 4 to 1 goes in...
themud

Pinion gear strength is insignificant. Older CJ's came stock with 5.38's in D25's and D30's. Different gear ratios have different teeth counts and a higher (numerically) ratio might have more tooth engagement than a lower ratio simply because of that particular tooth count.

But, I didn't think you could go lower than 4.88's in a HPD30. While you'd like the 4.88's better than the 4.56's, I doubt it's enough diffrence to be worth the hassle and expense, especially if it's not a daily driver. BTW, it's a 7% difference from 4.56 to 4.88, so drive 60 mph and note your RPM, then add 7%. That's roughly 175 rpm.