Final Drive Rebuild - with bearings?

[pago cruiser]

Did a search, and no real answers.
My rear end... has been a little sloppy...   on decal; then some slop when rolling on.  Had a rear flat, so it was time to inspect.  The spyder gears are a little worn - I replaced them 2 tires (7500 miles) ago.  The drive gears maybe 2x as much - there were showing slight tooth deformation at the same time.  Still runnable for at least another tire change or so.

Looking at ebay, complete pumpkins range from $400 to about double; with few, if any, details of wear or miles.  Looking at the parts fiche, the gearset is about $250.  I do most of my own work, so unless I needed bearings or seals, this seems the way to go.

But.
Bearings and seals would add up to another $200 or so.  Yet as...beefy... as these bikes are, I am not entirely sure bearings would be required. The bike has about 100k on it;  but I do rider her pretty hard - with good maintenance.  While my commute is a leisurely 45 miles at 80-85, once a month at least I get a good 800-1000 mile or so ride in.  Some high speed work, with lots of fast twisties - think the 191 north out of Safford AZ to Alpine - the best 150 miles of curvy roads in the world, IMHO...  But I digress.

So bearings - yay or nay? Opinions? Experience?  Can't confirm until I get it apart, but it has to wait a couple weeks until I get back from a work trip overseas. 

This sure seems to be a weak point on this bike; once I get out of this dam job that sucks the oxygen out of my life  , I need to see if the GL1800 swingarm/pumpkin would align with the Valk engine output shaft.  Back on my "Super Valk" project, I got to the point where I finished modifying the Valk frame to accommodate the solo 1800 shock, and moved the swingarm mounts to align the GL1800 swingarm/pumpkin with the 1800 engine in the Valk frame; but there the project stalled.  Not technically - but just timewise.       

[Brian]

Without knowing exactly why your ring and pinion are wearing is the reason I would replace the bearings and seals. Not stating this from experience, just my two cents.

[Moofner]

I can point you to a gentleman in KS that has multiple GL1500 rear drive assemblies with an average of 30K miles. You'll be able to get most of what you need from them. I purchased 2 assemblies to replace my worn drive splines and wheel flange. I even used one of the bearings to replace my valk bearing Everything matched up (including bearing part numbers), you would just need to cannibalize all the parts in there to your housing. After that, you might need some new parts to get the ring deck height right, such as spacers and then new seals.

PM me if you'd his details. I picked up a 2000 and 1999 assembly and can personally verify that he has about 15+ more setups ranging from 1994-1999. Oh, and I paid $60 for BOTH of my assemblies. That included swingarm, drive shaft, and final drive.

[Ricky-D]

When replacing gears in the differential, and for long life of the new gears, it is imperative that a tooth pattern activity is performed.

Bearings regardless of age are not a maintenance item and do not need replacing unless an inspection would reveal that replacement is necessary.

The shop manual details all the information necessary to replacing the gears in the differential.

Shims and seals are the only other items needed, besides the gears to rebuild the differential.

***

[Alberta Patriot]

Gear marking compound to check contact pattern:
https://www.amazon.com/AQP-Prussian-Various-Makes-80038/dp/B07DXH6PM7/ref=sr_1_fkmr0_1?keywords=Permatex+80038+Prussian+Blue&qid=1552324481&s=gateway&sr=8-1-fkmr0

[F6Dave]

Last year I pulled the final drive from my old (1988) BMW R100GS.  I was planning to rebuild it because, amazingly, BMW still sells the parts.  After opening the case I saw that the damage was far worse than expected.  A bearing race had broken, causing the drive to completely lock up.

I found a good replacement on eBay for under $250.  I installed it and the old bike has been running great ever since.  With so many low mileage Valkyrie final drives available I'd be inclined to replace it and keep the old one for a spare.

BTW, here's what major final drive damage looks like!

[indybobm]

If you were riding this when it happened the pucker factor must have been enormous!

[F6Dave]

If you were riding this when it happened the pucker factor must have been enormous!

It definitely got my attention.  Luckily it happened as I was coming to a stop at a traffic light, at about a walking pace.  I had to get out of the intersection so I backed up a few inches, which must have dislodged some of the fragments, as I was able to ride it through.  I was about a mile from home so I continued riding.  It locked up twice more on the way, certainly adding to the damage.