Transfer case noise

[tony]

Hi, so i have a 1986 RRC transfer case in my 110 that has an Ashcroft selectable 4X4 option and its making a noise like an impact gun but only in 4x4 and only during over run. Any ideas as to why?

[red90]

Front u-joint?

[red90]

It would be doubtful that the problem is in the transfer case. In 2WD everything is spinning the same as in 4WD. The only thing that happens is the front and rear output shafts are connected.

[DBrands]

I second the U-joints. My only other experience with similar issues, was worn radius arm to axle bushings; on initial over-run it was as though the axle was racking forwards and backwards in the worn out bushings, causing a similar feeling to worn u-joints.

[tony]

U joints are good, i barely use them as the locking hubs are usually disengaged. Going to first try another drive shaft and see if perhaps the drive shaft is not far enough out of phase????

[red90]

Then probably something in the front axle. Not using the u-joint does not mean they will last longer. They fail when the seals let dirt in. It can be worse for them not to be used.