Thread: Rear diff whine

Wheel bearings are a possibility,, they generally don't make too much noise unless absolutely rooted. Jack the truck up, wriggle the tyre and feel for play, stuffed wheel bearings often leads to oil leaks from axle seals, The oil drops into your drum brake and then weeps out the drum onto your rim.
Your other option is diff bearings, normally the pinion bearings that give trouble first. Lay underneath grab the pinion (rear of the driveshaft where it bolts to the rear diff, and wriggle it and feel for play (up/down, left/right, not rotational play) Check your diff oils for water contamination, if you have done any water crossings, or played in water over 40cm (ish) and you don't have extended diff breathers there is a good chance you have water in your rear diff, and that is a bearing killer.
Is the noise you are hearing RPM related or speed/acceleration related? If RPM related it could also be a gearbox or transfer case issue, output bearings can give up if your oil level is too low or if you get water in there, (deeper water crossings etc, no extended diff breather)
Have a good look for oil leaks around your rear diff and your transfer case/gearbox, it could point you in the right direction.

Originally Posted by ROKTOY

Wheel bearings are a possibility,, they generally don't make too much noise unless absolutely rooted. Jack the truck up, wriggle the tyre and feel for play, stuffed wheel bearings often leads to oil leaks from axle seals, The oil drops into your drum brake and then weeps out the drum onto your rim.
Your other option is diff bearings, normally the pinion bearings that give trouble first. Lay underneath grab the pinion (rear of the driveshaft where it bolts to the rear diff, and wriggle it and feel for play (up/down, left/right, not rotational play) Check your diff oils for water contamination, if you have done any water crossings, or played in water over 40cm (ish) and you don't have extended diff breathers there is a good chance you have water in your rear diff, and that is a bearing killer.
Is the noise you are hearing RPM related or speed/acceleration related? If RPM related it could also be a gearbox or transfer case issue, output bearings can give up if your oil level is too low or if you get water in there, (deeper water crossings etc, no extended diff breather)
Have a good look for oil leaks around your rear diff and your transfer case/gearbox, it could point you in the right direction.

Just reading this, will this also be an issue on other manufacturers (Suzuki Vitara perhaps?) I have had it not quite floating but barely touching the bottom once. It was a while ago so any damage is probably already done, but now that you mention it, is this something that I should think about? Diff oil etc??

Originally Posted by timattalon

Just reading this, will this also be an issue on other manufacturers (Suzuki Vitara perhaps?) I have had it not quite floating but barely touching the bottom once. It was a while ago so any damage is probably already done, but now that you mention it, is this something that I should think about? Diff oil etc??

Definitely check oils after deep water especially if no extended breathers.