Help Differential Noise!

[TJones]

Strange noise coming from the differential then it stopped...

[CHEESE_WAGON]

Welp... I guess that's ONE way to fix it.

[Native]

How does something like that even happen? It looks like the axle just decided to disconnect while driving down the road.

[Sehnsucht]

This is why bus manufacturers won't unlock six gear! LOL No but seriously this seems like it can only be the result of two things, either perpetual oversight of both daily and annual inspections which allow the suspension components to loosen or fatigue or else a shock or impact that jostles the suspension so severely. I've seen this with trailer tandems but they're not as securely affixed as drive axles. The only drive axle dislodged like this I've seen was a video of a military vehicle testing and they locked up the wheels on dry pavement, setting up a 'skipping' behavior that overtorqued the mounts.

https://youtu.be/_rjyfGyFdds

[Native]

That video was enlightening. So the bus above was probably cruising along when the driver noticed the light change tored or someone cutting across the intersection. The rear brakes locked up causing the same shuttering vibrations and ripping the rear-end out. Interesting.

[Jolly Roger bus 223]

nah this should have never happened even if the cheap school district ordered it with cheaper bolts?
this should have never been an issue and probably wasnt?
to many are playing the photo shop mess these days?
i call BS

[CHEESE_WAGON]

This was purely due to lack of proper inspections. Quite likely the axle mount and spring mount bolts were neglected and allowed to rust or crack to the point they finally broke. I've had a leaf spring crack on an 18-wheeler myself. This is why inspections aren't to be taken lightly.

[Brad_SwiftFur]

Originally Posted by Jolly Roger bus 223

nah this should have never happened even if the cheap school district ordered it with cheaper bolts?
this should have never been an issue and probably wasnt?
to many are playing the photo shop mess these days?
i call BS

No, that's a genuine photo. This is an extreme and rare but very valid example of why annual inspections, and pre-trips are so important. Especially so for buses that have racked up some years and miles and even more so for those in or from The Rust Belt.


This is something that ordinarily should never happen, and with proper inspections - and yes, occasional replacement of springs, shackles, bolts, and whatever else - is very unlikely ever to happen.

[CHEESE_WAGON]

My money is on differential gears and / or wheel bearings locking up. Even with good axle / spring mount bolts, that could do this. I've seen a dual wheel assembly go bouncing off down an embankment from a hub bearing locking up at highway speed. Not common, but it does happen. If the pinion bearing seized, it could very well do this at 65 mph.

[Ronnie]

I did see on the Ohio turnpike a set of duals still attached to each other on the shoulder. Shortly after I pulled into a rest stop for the night, and right there was a fellow missing one set of duals including the brake drum. Guessing axle nut or wheel bearing failure. I have had axle u-bolts fail and the axle got real crooked. Once on a new axle, turns out the spring perch was not welded enough and the axle spun with a hard brake application.

[ol trunt]

I had a front "U" joint fail on an old Chevy Carryall 4X4 at highway speed. It did a quick pole vault and left the drive shaft behind. I put the thing in 4 wheel drive and crept home with front wheel drive.
Jack

[Native]

I had an '87 GMC Jimmy 4x4 loaded to the windows with Christmas gifts late at night on the way to Houston. The rear-end ceized up. Fortunately, one of the gifts I was bringing was a full cold chisel set. I used the "gift" to break out the gears and I limped on in the last 100 miles on front wheel drive.

[cadillackid]

Wheel Hop! ive seen it on race cars end up in exactly this situation.. bus would be no different.. kind of unusual on an RE where you have good weight.. but still could happen..