Front End GRRRR sound (1 Viewer)

Searched on GRRR and didn't find what I'm looking for. Most of the posted GRRR noise is related to a lift.

I have a stock 1997 LX450. Ever since a diff / xfer gear oil change I've been getting a GRRR noise from somewhere in the front end. It used to be only over 100 kph, but is now starting at around 80 kph. There's a bit of a roughness or very slight vibration noticable too.

Driving at 90 kph I've put it in neutral and there is no difference. There is also not much of change in the noise as I go faster.

As soon as I get a grease gun I'll shoot all of the zerks. What type of grease is best? I'm also going to change the gear oil.

Could this be a bad bearing or U-joint?

I had several threads on the Grr sound. Replaced the U joints in both drive shafts and had them balanced and the Grrrr went away.

Was the noise constant?

Is it difficult to replace a U-joint?

The Grrr sound has different characteristics. It can be there during acceleration, decelleration or both. Sometimes it's there when you barley take your foot of the gas. These are different symptums seen by lots of folks on this board. Taking apart the drive shaft and cleaning the grease out of the spline has fixed it for some, U joints for others. You can take a drive shaft off and see if it makes a difference. If the sound goes away, do that shaft first. I had a driveline shop do my U joints and I insisted on Toyota joints. Here are a few links that might help you. There is probably more, change your search to drive shaft, drive train, etc.

https://forum.ih8mud.com/showthread.php?t=22649 ( From FAQ)

https://forum.ih8mud.com/showthread.php?t=56684

I spent hours reading through the posts using different search parameters.

I've been fighting mine for a long time (and no solution yet). When did it start? Was there something else you did when you changed the gear oil, like say rotate the tires? The easiest way to check the ujoints is to remove one drive shaft at a time, lock the center diff, and see if the noise goes away as you drive. Removing the drive shafts is a snap. You must have a center diff lock switch to do this, however. While you have each shaft off, check the output bearings for vertical play (which they shouldn't have). Another possible cause is a tire problem (balance, belt). I'm going to borrow another set of tires/wheels to drive and see if that helps me.

John