Whirring sound

[trentski]

Hi Everyone,

I had the rear diff pinion seal replaced in my LN167 recently as there was a bit of diff oil leaking. It was right for a week and then it showed signs of leaking again - so they had another go at the seal and this time it fixed the problem. Within a day or so of the seal being replaced, I noticed a whirring sound that seems to be coming from about the same spot. The sound can be heard on acceleration, when coasting and when decelerating (during deceleration or with the foot on the clutch it sounds like when the engines on an airplane are slowing down after the plane has come to a standstill on the runway).

Without a lot of mechanical knowledge and after searching the web, I'm thinking it could be the pinion bearings. But I'm also thinking there is too much coincidence here - the sound started very soon after the work was done on the seal.

Anyone got thoughts on what could be going on here?

[danmcccc]

i dnt know how the pinion bearing in them are set up with preload and backlash etc...but by the sounds of things the seals where leaking coz there was some backlash (freeplay) in the pinion bearing, this movement caused the seals to fail...so whoever has done the job has nipped the pinion bearing up to get rid of the backlash but they have now put too much preload (tension) on the bearing causeing it to get hot and sorta wind up a bit which is what is making the noise...or it could be the other way around but the seal just hasnt failed yet and the bearing doesnt have enough preload and the bearing is failing....either way it sounds like a pinion bearing

[Jack S]

X2 what Dan said

[danmcccc]

X2 what Dan said

x3 what jack said