Another Rear seal leak question.

[Ramseybella]

After 53k mile my rear differential is leaking on the inside between the hub and the Pumpkin, not major but it's spraying a little on the rim.
Since I am going to put on a set of tires it will get done all at once.
My mechanic is going to fix it but he want's to install a new Bearing 19 on the blowup attached $63.00. 10 Shim, Ring Gear, 25 Oil Seal and 21 O-Ring.
Is this necessary? I know it needs the O-Ring and maybe the seal. :-\
Just had the valves checked in specs just needed plugs and throttle bodies tweaked a little that was good news.

 

[gv550]

It is possible the bearing has failed (loose, rough, rusted, dirt) and caused play or runout of the shaft resulting in the oil leak. More likely it is just a tired seal, but I can understand the tech wanting to have a bearing on hand just in case. And while it is all apart, why not make it all new?
It is probably a bit of over-selling, but a one hour job could become a week wait if it turns out the bearing is needed, and they don't have it on hand.

 

[Ramseybella]

Thanks!
He is very conservative when it come to repairs and owns his own shop, been dealing with him for years.
He charges me at cost and free labor for tires and next to nothing for larger jobs when I buy the parts. I have been selling motorcycle parts and vintage BMX bikes for him on Ebay and deduct the Ebay and Paypal fees he packs the items and ships them off.
So he has been grateful, A Win-win deal!! The cheapest I found for all these parts total shipped $101.55 on PartsFish.com..

 

[Checkswrecks]

Truly not a bad idea to replace it.

 

[allsop]

My mechanic is going to fix it but he want's to install a new Bearing 19 on the blowup attached $63.00. 10 Shim, Ring Gear, 25 Oil Seal and 21 O-Ring.

http://www.partsfish.com/oemparts/a/yam/5085c72cf8700223282354b4/drive-shaft
there is 4 different shim sizes. Do you know which one you will need or are you getting them all? The final gear backlash is adjusted with the shim or shims

 

[BWC]

You might to just try and replace the seal first. I had the same issue awhile back and changed out the seal by removing it from the outside without removing the bearing housing. Chances are unless you know of some damage done to the final drive the bearing is probably OK.

Found this at a tire change

I very carefully drilled a 3/32 hole in the seal with not letting the bit run to deep and touch the bearing.
Wound in a small screw to pry the seal to, which came out pretty easy.

Installed the new seal. The tricky part is to carefully use the old seal to tap the new one in to the old position which is just flush with the end of the tapered section of the housing. There is no lip on the inside of the housing to stop you from setting it in to deep.

Ready to put back in service. I removed the final drive to make installation on the bench a little easier. And from what I could see the old seal and it's running surface on the splined drive looked to be in perfect shape. What I did notice is the seal has an inner and outer lip. Inner to direct the oil back into the final drive and the outer is a dust seal. Between the two was some muddy oil which was probablly allowing it to weep. I probably could have given it a good cleaning and it may have stopped leaking.

And a few more pics.

The directional seal with the inner lip to direct oil back into the housing.

 

[Ramseybella]

http://www.partsfish.com/oemparts/a/yam/5085c72cf8700223282354b4/drive-shaft
there is 4 different shim sizes. Do you know which one you will need or are you getting them all? The final gear backlash is adjusted with the shim or shims

Good question, don't know..

 

[hogmolly]

http://www.partsfish.com/oemparts/a/yam/5085c72cf8700223282354b4/drive-shaft
there is 4 different shim sizes. Do you know which one you will need or are you getting them all? The final gear backlash is adjusted with the shim or shims

Normally you go back with the same shim stack that was in there originally unless you know it was shimmed improperly. Was the drain magnet full of bearing material? If not, it was probably just a seal. I would have likely pulled the two halves of the housing apart so the bearing can be checked without the need to pull it from the ring gear.

 

[Ramseybella]

Normally you go back with the same shim stack that was in there originally unless you know it was shimmed improperly. Was the drain magnet full of bearing material? If not, it was probably just a seal. I would have likely pulled the two halves of the housing apart so the bearing can be checked without the need to pull it from the ring gear.

No, the gear oil was clean and clear last time 3k miles ago, the mag plug had a small minute amount of the usual fine material, barely made a stain on a Q-tip.
Actually I didn't need to change it but I did anyway.
I cleaned the bike up yesterday washed it got all the crud off the bottom of the differential and checked the shaft hole it was clear of fluid nothing leaking and was not blocked.
Cleaned the rim off and will take it for a 100 mile spin today and see if it is still leaking.
I think a seal will be the easy and less expensive way to go first. I have never felt any issue with the drive shaft since I bought the bike. It did go in for recall work on all the 2012 issues.
I will follow up after the ride.. ::26::
Thanks guys.
Pete