grinding noise when under load?

[quadracer0387]

heard this tonight... i was turning up a hill and heard a grinding noise from the front. belt is tight. maybe torque converter? tranny shifts fine. also tried from a stop and only grinds if i step on it hard... any ideas?

[DETOURS]

Front wheel hub bearing assembly, not that unusual.

[Mudderoy]

Yeah how many miles, and were you in 4x4?

[quadracer0387]

sounds more like something is sliping, like gears are not catching.... 2wd 156,000

[Mudderoy]

I knew exactly what it was until you said 2wd. Wait the XJ is a 2wd not a 4wd, that you have in 2wd?

[quadracer0387]

its a 4x4 but its grinding when in 2hi in the front

[Mudderoy]

If it is a popped noise that sounds like a chain slipping, it isn't in 2wd, it is in part time 4wd and the drive chain in transfer case is slipping over the gears.

The chain should be replaced at 100k.

Is it a NP242 or NP231? The 242 have a problem with wearing a grove and making it difficult to get out of full time 4wd and into 2wd.

Put it back in full time and while going slow put the transmission in netural and then put the 4x4 selector to 2wd. I have to be going about 20 mph in mine but it works every time.

Once you have it out of 4x4 see if the noise has gone away.

[quadracer0387]

this is just in normal driving... i can switch between 4hi and 2hi with no problem. would the chain in the np321 cause this in 2wheel drive? ill try it in 4 wheel tomorrow.

[quadracer0387]

thinking it may be my fan hitting the shroud... my motor mounts are worn pretty bad, so its possible the motor is moving so much that its making my fan hit... im going to check it tomorrow just in case.

[BlueXJ]

If it isn't the fan then the front unit bearings sound like what you described.