1975 850T Survivor Project

[Antietam Classic Cycle]

I've found that if the steering stop is knocked off, then there's a good chance that the frame is bent. Find a surface that is as close to perfectly flat as possible, place the main frame (no lower rails or anything else attached) on it and see if the front engine mounts both touch or if one is up off the surface. Frame may rock side to side as well.

Removing the rear drive from the swingarm will not disturb any shimming - that is all inside the pinion carrier which should stay inside the rear drive housing.

If you're having the swingarm powdercoated, then all of the bearings (pivot and u-joint carrier) will need to be removed. The carrier bearing should be replaced anyway.

[cmice]

I've found that if the steering stop is knocked off, then there's a good chance that the frame is bent. Find a surface that is as close to perfectly flat as possible, place the main frame (no lower rails or anything else attached) on it and see if the front engine mounts both touch or if one is up off the surface. Frame may rock side to side as well.

Found a couple of flat spots and tried a few different orientations, feels pretty square to me.  If I do get wiggle it's less than 1mm or even less if I move it around to find a happy spot on the floor, so I'm going to call that the floor.

Removing the rear drive from the swingarm will not disturb any shimming - that is all inside the pinion carrier which should stay inside the rear drive housing.

If you're having the swingarm powdercoated, then all of the bearings (pivot and u-joint carrier) will need to be removed. The carrier bearing should be replaced anyway.

Ok, easy enough then - will do on the carrier bearing.  I was able to push the vin-plate rivets out from inside the steering neck and I didn't even lose any! 

Any other specific tips on dealing with the powder coater? They have done quite a few bikes so they know their way around - but sometimes overconfidence gets in the way (or unfamiliarity with Guzzis) and things that shouldn't be coated get buried.  I kinda don't want to take the steering head lock out (I do have the key), maybe that's a fools errand it should come out anyway?

[faffi]

Personally, I would never consider to strip a fully functional final drive unless you A) want to learn how they go together or B) want to be absolutely certain it is well within spec. Or both. I have never considered either A or B as the risk of doing something wrong is too great for comfort. For me. Plus, should one fail, they can be found cheap secondhand.

[cmice]

Personally, I would never consider to strip a fully functional final drive[...]

I've set pinion depths before on a Hewland mk9 - but it's not something I'm eager to do again.  Life is simply too short for that kindof nonsense.
 

[Antietam Classic Cycle]

Any other specific tips on dealing with the powder coater? They have done quite a few bikes so they know their way around - but sometimes overconfidence gets in the way (or unfamiliarity with Guzzis) and things that shouldn't be coated get buried.  I kinda don't want to take the steering head lock out (I do have the key), maybe that's a fools errand it should come out anyway?

The steering lock comes out easily, so for me it's a "no brainer" on removing it. You either use a thin blade of some sort to pry under the cover near the rivet, or sometimes tap it loose with a long drift (it you can find a good angle). Then use the key to remove the lock.

I ask the powdercoater to tape over where the lock cover, steering head and swingarm pivot bearings go, the front and rear of the driveshaft tunnel and point out where all of the threaded holes are in hopes that they'll plug them.

Personally, I would never consider to strip a fully functional final drive unless you A) want to learn how they go together or B) want to be absolutely certain it is well within spec. Or both. I have never considered either A or B as the risk of doing something wrong is too great for comfort. For me. Plus, should one fail, they can be found cheap secondhand.

Rear drives aren't rocket science if you're just going in to replace the seals. It's always nice for gear lube to stay inside, fresh seals are a way of helping to insure that. As long as one uses the same number of gaskets (normally 2 - one on either side of the large shim), there not much of a chance of messing things up. There's no seals in the pinion carrier assembly, so no need to disassemble that. "Cheap secondhand"  Maybe for Hondas and Yamahas, but not a good one for an 850-T - expect to pay $400 and up. 

[cmice]

Steering stop repaired - no judgement on my welding skills.



The steering lock came out pretty easy as Charlie pointed out; with the key, it's no problem.

I got the retaining clip out of the carrier bearing, but it won't budge with fairly assertive use of hand-tools.  Do I need to press this out from the back side?  And how best to get the bearing shells out of the swingarm itself?

[Antietam Classic Cycle]

I got the retaining clip out of the carrier bearing, but it won't budge with fairly assertive use of hand-tools.  Do I need to press this out from the back side?  And how best to get the bearing shells out of the swingarm itself?

A blind hole bearing puller set really comes in handy here.




I install one of the collets into the carrier bearing so that I have something to drive against with a long steel bar and hammer from the back side.

The kit slide hammer and largest collet will remove the pivot bearing outer races as well. Some mechanics prefer to run a bead of weld around the inside of the race, which shrinks it when cooled, allowing it to be removed easily.

[cmice]

Whaddaya know - the welding trick worked a treat. They didn’t just fall out, but shrunk enough that I could rock them back and forth and walk them out of the bores.  Maybe 30 minutes work.  The carrier bearing put up a real fight, probably 7-8 tons to get it to pop.


Should have frame, cradle and swingarm out for paint this week.

[cmice]

Center stand apart, everything bagged and tagged so I can hopefully remember how it to put it all back together again.

How about these center-stand links and the crankcase vent tube bracket - coat these too?  Don't know if the center-stand links an aesthetic decision or a functional one.

[Antietam Classic Cycle]

Center stand apart, everything bagged and tagged so I can hopefully remember how it to put it all back together again.

How about these center-stand links and the crankcase vent tube bracket - coat these too?  Don't know if the center-stand links an aesthetic decision or a functional one.

I zinc-plate those, as they were from the factory.

[cmice]

Today was final-drive day.  I was being pretty cautious because this is an area where you can make a whole lot of work for yourself if you're not careful.  It's not that hard, just have to pay close attention to things and know when is enough.  At first I was just going to do the wheel-side big-seal and give everything a clean, and then I spotted the "outer" seal hiding down in there who's probably been in there for 51 years.  I stewed over it for a bit, and figured what the h*ll - I've heated bearing shells in/out of Hewland cases, how hard can it be?  Turns out, not too hard.  I couldn't find my MAP so I settled for propane - in the end probably a good call anyway, takes longer but the heating is more controlled.

Clamped the housing vertically in some soft-jaws, and started to work with the propane going around the outside of the shell area and ribs, while periodically checking with IR thermometer.  When my thermometer read about 140deg F (who knows what the actual metal temp was), the shell pulled out with gloved fingers.  Lip seal came out without much of a fight.  With the pinion assembly removed (that's NOT coming apart, thank you), I could replace the o-ring there, and put the bare final drive housing in the bath.



Assembly is indeed the reverse of removal, outer seal, heat the housing to slip the copper shim and bearing shell back in again (well below 240deg), put the locking tab back on, needle cage and needles, and drop the ring-gear assembly back in after lubing everything.  Then pressed in the big lip seal with the wood plank and dead-blow techinque, paper, shim, paper, and torque that all down with waves.



Hoping to get the frame off to the powder coaters tomorrow, and we can work on the rear wheel and rear brakes.