Thread: "Crunch" from rear drivetrain.....

hmmm, diff? The planetary gears do crumble in them.

It mght be interesting to drop the oil and see what comes out.

planetry gears in a rover diff?


(Im guessing you mean side gears or spider gears)

Yup, the spider gear. The sun gears (side) seem to be pretty strong for the diff though.

Originally Posted by Blknight.aus

planetry gears in a rover diff?


(Im guessing you mean side gears or spider gears)

Topologically speaking they could be described as planetary gears.

The crunch could possibly be a bearing or maybe even outside the works - loose wheel? loose drive flange on the pinion shaft? Presumably a loose suspension bush would show up with other symptoms, but perhaps a cracked mounting on one of them could give the crunch without actually having much play.


John

Originally Posted by JDNSW

Topologically speaking they could be described as planetary gears.

The crunch could possibly be a bearing or maybe even outside the works - loose wheel? loose drive flange on the pinion shaft? Presumably a loose suspension bush would show up with other symptoms, but perhaps a cracked mounting on one of them could give the crunch without actually having much play.


John

Thanks John,
I'll check all of that this morning, will post up what i find

Cant post pics unfortunately, my better half has the camera with her (it's her hens day touring the yarra valley wineries.

Anyway, back to my dilemma, dropped the diff oil and can only describe the magnetic sump plug as resembling Sideshow Bobs (from the simpsons) hairstyle. Lots of shavings about the size of cut fingure nails and the end of a 4 or 5mm roll pin
Am about to look through rave to see if i can identify where the roll pin is from, any ideas?
So i guess i'm up for a rebuild, what costs am i looking at? This is the time to put in a Locker?

Cheers all
Phill

It probably depends on the bulider as to what he wants to do and how much damage is done.

If the Crown wheel and pinion are damaged the cost will go right up.

You could probably do it yourself and quite possibly get away with replacing the planetaries and the pin if thats the only damage. That would be a day and probably $150 or something. Parts from Four Wheel Drives in VIC somewhere.

A builder would probably replace the entire hemisphere (the big diff lump that rotates) and it'd probably be lots.

You could get a locker which would not only repair it, but will probably mean that the diff will never break again. Cost depends on the locker or even a TruTrac would be an excellent option and good value.

But yep, if you want a locker, now is the time.

I have just recently replaced the centre in my front diff and the cause was the top circlip failure on the differential gears cross-shaft which then slipped down and @ 25mm of the shaft broke off. This also took large chips off most of the crown wheel teeth. The diff would grind infrequently on a left turn and I could hear a chipping noise rebounding off a freeway wall whenever I was driving close to it. I have taken photos but can't post them as I am at work until next Wednesday.
Regards Maggsie