Differental question

[Smoke Doc]

The rear diff went to the happy hunting ground today, the front diff has been on it last leg, they are 3.55''s. I have been planning to swap both with 4.11s. Can I replace the rear with the 4.11, then the front at a later date, and still drive?

 

[BaconYJ]

Yes.... if you never put it into 4wd with the front diff being a 3.55. Best bet is to just remove the front drive shaft until you do replace the gears on the front differential. If you happen to put it into 4wd with the different numerical differentials you will break something.

Bacon

 

[Bounty__Hunter]

Definitely remove the front driveshaft or you will grenade the transfer case, even in 2wd.

3.55 to 4.11 is a minuscule jump, sure you don't want to make it more worthwhile?

 

[Smoke Doc]

Thank you both for the reply 4.11 is as big as I an go without all kinds of fab work, or a very expensive up grades. I good with the performance of my YJ. I need 300 or 400 RPM @ 70MPH. I can pickup the rear for 900.00, front 400.00 both have less than 70000 miles on them. I do not think I can rebuild what I have for that. So I guess used is the best way for now. Thanks again

 

[Bounty__Hunter]

Seems very high for stock 4cyl axles, or is there more to them?

Sounds like you thought out the ratio well, good. Just trying to avoid regrets.

 

[JPNinPA]

Thank you both for the reply 4.11 is as big as I an go without all kinds of fab work, or a very expensive up grades. I good with the performance of my YJ. I need 300 or 400 RPM @ 70MPH. I can pickup the rear for 900.00, front 400.00 both have less than 70000 miles on them. I do not think I can rebuild what I have for that. So I guess used is the best way for now. Thanks again

300-400 rpm for 70 mph?.? What engine?. Wouldn't this be lugging the engine?

 

[69jeepcj]

I assumed he ment 300-400 rpm more than he currently has at 70.

 

[Smoke Doc]

Yes that is what I meant a have been having trouble entering text. The 1900 rpm at 70 mph has a difficult time managing hwy grade. If I start the same grade 2200 rpm can make the grade without down shift. Anyway I don't want to run 2500 rpm at 60 mph. Its 125 miles one way to my deer lease, I spend a couple weeks a month down there would like to keep some hwy performance.

 

[Smoke Doc]

YJ has 4.0 1900 rpm at 70 mph doesn't lug, it does lose speed till I have to down shift.