lifted93xj

Is it normal that my 4x4 high has a pretty loud whine to it when i decelerate. When im driving it seems fine. Also the t-case is a 231 so its part time. let me know what you think. thanks

BuckB91XJ

This whine is totally normal when driving at high/road speed with an NP231 in 4HI, or 4LO for that matter. Mine really whines when I've had it going 30 mph on dirt roads in 4LO for short periods between trails. I've also read and heard that other guys with the NP231 have the same noise. Nothing else is wrong just a whine at high speed in 4WD.

lifted93xj

thats what i thought but it sounds like its coming from the dana 30 on the front and i was going like 20-25.

lifted93xj

I think its just coming from the t-case but idk.

jp4wheelin16

Noise only while decelerating is usually caused by pinion bearings being bad or wearing out or the preload not being set right

lifted93xj

how do i fix the preload if that is the problem?

96Cherokee

i know i have the 242 tcase and my jeep whines accelerating and slowing down..my friends jeep did the same thing..ive grown to love the noise

BlueXJ

Check the diff fluid level and also that of the transfercase. If they are OK then I wouldn't worry about the whine. Most all 4x4s will whine some while engaged. If the pinion bearing is going out it usually leaks a little at the yoke. That has been my experience anyway.

lifted93xj

thanks guys for the info. I just changed the diffs and t-ase fluids like 2weeks ago.