Hadn't ever really used 4 Low in my cherokee. Is it normal for it to be a little loud with gear whine? I assumed it was normal but I want to make sure there isn't anything wrong.

sean

 

It does not say in your avatar what year you have, but if it is an early model, yes it is normal for the NP208. They had straight cut low range planetaries.

 

yeah, my 231s have some 4lo gear whine. it's normal.
not sure about 242s as i don't use any, but i'm sure it's there too, and normal.

 

yea it is normal for any 4-lo to whine. the reason is because it is spinning sooooo fast when the you have the gear reduction down. you have to understand that you are getting bigger gears so to go say 10mph in 4-lo. i know i run 3000 rpm's when locked in first gear 4lo. for example. an aw-4 tran's first gear is a 2.804 the 242tc low is 2.72 and say a stock axle ratio of 3.55. so your looking at a 27.075:1 ratio. that means your driveshaft spins 27 times for your tires to rotate once. now do you see why you would have a whine?

 

My Cherokee is a 1994, 4.0I with I think the 231. It is the tc that is not all time 4wd.

 

well i had a error in my post.. i said driveshaft but what i meant is your trans spinning 27.1:1. that is your crawl ratio and the np231 transfercase has the same gear ratio as the np242. they work the same way and i have both of them too.. there is nothing wrong with a wine in 4-lo. when you hear a grinding sound thats when you have problems.....