Dana 30 ratios

[Dammerung]

I’m looking for a 3.73 ring and pinion for the front Dana 30, but it seems like almost no one makes them or they’ll cost an arm and a leg to get. Anyone have any idea where to find one for relatively cheap?

[The86manche]

Zj grand cherokees. Limited trim will have 3.73s.

I have a 3.73 ring and pinion but it's from a 35 I don't know if it would work for a 30..

[Pete M]

ZJs have a low pinion Dana 30 so it wouldn't work anyways in an original MJ axle.

[The86manche]

If you don't mind the low pinion, can always swap the whole axle then 

[cruiser54]

Yes^^. V8 ZJ is a good candidate. 

[ghetdjc320]

3.73 is an uncommon ratio to go with. If you must have it though grab an aftermarket set. Swapping in an lp axle is a step backwards

[kryptronic]

YJs with the 2.5L engine and an automatic transmission will have 3.73 ratio gearing as well, however this is a rare combo to come across.

[Caish]

Some XJ's with tow package had 3.73's also got a D44 rear axle, as did the Metric ton comanche. 

Yep ZJ/WJ won't work in a XJ/MJ low pinion vs high pinion. 

Might as well swap to a 4.11 or was it 4.10's from a four cylinder. 

 

[ghetdjc320]

Yeah, don’t go with 3.73. 3.55’s or 4.10 depending on drivetrain and tire size

[Dammerung]

Yeah, don’t go with 3.73. 3.55’s or 4.10 depending on drivetrain and tire size

I’m planning on running 31s, but it’s mostly gonna be an in town/daily driver. I thought about 4.10s but I figured they’re too low for what I needed.


1988 Jeep Comanche Pioneer
4.0 Liter w/ AW4 2WD

[ghetdjc320]

2 minutes ago, Dammerung said:

I’m planning on running 31s, but it’s mostly gonna be an in town/daily driver. I thought about 4.10s but I figured they’re too low for what I needed.


1988 Jeep Comanche Pioneer
4.0 Liter w/ AW4 2WD

4.10’s would be great with the aw4 and 31’s. I ran 3.55’s for several years on 31’s with a ba10/5 tranny and it was quite manageable. The d30 carrier break at 3.73 is what kept me from swapping gears earlier. 

[Pete M]

4.10s are fantastic for 31s.   

[Dammerung]

Are you guys sure about that? Not trying to be dismissive, but I’m gonna be using mostly for driving around town and some highway for college. I just want to try and get a good combo of gas mileage and power, especially with how gas is almost 5 bucks around here right now.


1988 Jeep Comanche Pioneer
4.0 Liter w/ AW4 2WD

[cruiser54]

Go 4.10s. You'll be fine

[Jeep Driver]

53 minutes ago, Dammerung said:

driving around town

If you notice anything you'll likely have a little more pep and better mileage around town. 

 

If you are patient and wise-

Find a pair of axles out of a late model XJ 2.5, will have 4.10s

Or at the least a 4.10 D30 and then regear the rear if you want to keep it. 

 

A pair of axles will cost you about $300, that's less than half the cost of regearing a single axle. 

 

To make my point, an example-

https://www.facebook.com/marketplace/item/289577182886008/?ref=search&referral_code=marketplace_search&referral_story_type=post&tracking=browse_serp%3A1051d5ca-03f2-45fc-be31-5f1534cb4090

 

Then spend your other $300 for a shop to help you set up your new rear.....if you cannot do it yourself. 

 

 

[Pete M]

The 2.5/auto came with 4.56 on tiny tires. Mpg is far more complicated then straight-up gear ratio.