Axle swap gear ratio

[Troop20fla]

I have a 1991 2wd short bed MJ with an automatic transmission and the 4.0. It has a Dana 35 in the rear. I have a Comanche Dana 44 with a 3.07 gear ratio. If I swap this axle in will I have an issues because of the gear ratio? 

[DesertRat1991]

You can run it.  Although your vehicle will accelerate 14% slower than it does now. 

 

Since you don't have a differential in the front axle, there is no concern regarding mis-matched gear ratios.  Lastly, the D44 snout is about 1" longer than the D35 which means you may need to shorten your driveshaft to get it to fit.  Alternatively, you could try putting a lift kit on the truck to gain clearance or ordering a custom aftermarket drive shaft. 

[Eagle]

With an automatic and stock size tires you won't have any issues. As DesertRat already mentioned, you'll feel some loss of acceleration, but it would be worse with a 5-speed.

 

He's spot on about the driveshaft. Figure on getting it shortened by 1".

 

 

 

[omega_rugal]

2 hours ago, Eagle said:

With an automatic and stock size tires you won't have any issues

 

or you can install slighty smaller tires but would want to do that

[thecodemonk]

Speedometer might be off too. On a 4wd there's a gear you can swap out, but I'm not sure where that is on a 2wd. Maybe the trans tail housing?

Sent from my Pixel 4 using Tapatalk

[Eagle]

4 hours ago, thecodemonk said:

Speedometer might be off too. On a 4wd there's a gear you can swap out, but I'm not sure where that is on a 2wd. Maybe the trans tail housing?

Sent from my Pixel 4 using Tapatalk
 

 

I forgot about that. Yes, you will need to replace the speedometer drive gear. It is in the transmission tailshaft housing.