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.

[cmice]

Allright - long time, no update.  In short a lot has happened.  Frame came back from the powder coater a few days ago.  Replaced the steering head bearings, but forgot that I'd left the upper triple clamp in the cleaner overnight and it stripped the paint off it, mostly.  So had to finish stripping that for prime and paint yesterday.



Reinstalled the vin plate and fork lock while we were working in that area. Put the lower rails back on, and the center stand - and I couldn't help myself for putting the frame back on.



While we were waiting for the frame, I got into the back end a bit.  Pulled the rear brake apart and did battle with those gawd-awful shoe springs.  That was a fight.  Wondered why the brakes were so difficult to operate...this is probably why...



Thankfully Curtis has them still and so an order from him turned up a couple of new ones (new left, old right).

In for a penny, in for a pound - the u-joint was notchy, so get to rebuild that.  Everything that could go wrong with these bikes seems to have happened to this bike as a complete study.  Man.  Anwyay, u-joint-store sent me 22x50 (which is what I ordered) only to pull the joint apart and find they're 20x44.  The nice folks there will swap me crosses and after US Postal gives it a tour of the united states, I should have the right joints in hand so I can finish putting it together.



Aaaand lastly, putting the swingarm back together and the driveshaft carrier bearing is really putting up a fight.  Any tips on how to install this without a bunch of heartache?  I'm soaking the bearing in dry-ice right now, so hoping some heat on the bore (but not enough to mess up my nice new powder coat) and maybe there will be enough clearance to get it to start.  No photo of that bit - I'm done for the day.

[cmice]

Brief update for today - went to a friend's place who has a proper press and a variety of different sized round objects to stick into it - made sure everything was square, and the carrier bearing went in without much complaint.  All the messing around with dry-ice etc wasn't working and wasn't necessary.  Was a fun experiment regardless.

[cmice]

Starting to look like a bike again.  Will post a photo later.  For now, a few updates...

Pulled the mufflers apart (Dunstall Decibels) to find out what's rattling around inside there.  And it looks like they were packed with old-style furnace filters sometime long ago.  Will re-pack these properly and see how long they last.  Have a crossover coming from Charlie which will let get the mufflers mounted correctly as well (they were just cantilever off of the header flange at the head - just no bueno).



New tires are inbound (Dunlop d404) - actually they're here just waiting on tubes - so time to get the front wheel in shape now that the back wheel and brake is done so they can go to the shop to get tires swapped.  This means pulling the forks out and apart and yeah, more joy.  One of the two dampers is on it's way out, so a new pair of those on order - that's the easy part.  The fork tubes are not so easy...and I cannot begin to describe the smell...





One is definitely worse than the other.  Both have pitting above the fork seal which is mainly a cosmetic issue.  But the wear around where the seal rides is through the chrome on one side, and getting there on the other.  I put them in a lathe today with some steel wool and oil and did what I could to dress them. "Better" but still not great.  Given how these forks work, the bike came with a set of "Leakproof oil seals" - will put those in, and mount the fork tubes 90deg rotated in the triples to see if we can make a new wear spot on the fork.  Any other words of wisdom here?

So inbound are - U-joints (more in a sec), h-pipe, fork dampers, tires and tubes.  All this will let me put the swingarm back on (ujoint), forks and tires on, and he can be back on his feet!

Speaking of u-joints, had GREAT customer service from Nathan at https://ujointstores.com/ - they have both size of guzzi joints, the 22x50mm for the bigger ones (T3 maybe?) and the 20x44mm for the T.  I ordered the bigger one by mistake, and they fixed it for me f.o.c.  Always want to plug those that support crazy people like me.  So hoping you give them some business as well.

On this subject, shout out to Harper Moto, Crusty Cycle, MG and of course Charlie at Antietam.  They're doing their best to keep us all rolling and none of this would be feasible (or even possible) without folks like them.

[faffi]

I have saved many stanchions that had pitting in the area where the seal move by using a fine oil stone to remove every peak. In my experience, cavities does not bother seals, only peaks. Anything that sticks up above the surface, regardless how little, will nip the seals sooner or later. To reduce the chance of new corrosion forming, I have then either fitted gaiters/bellows or put oil soaked foam, cut to fit around the stanchions, under the dust covers.

[cmice]

It's been a while, but progress has been happening.

Rebuilt the u-joints, and that is not a fist-fight I recommend having but it's done now.

When re-installing the rear swingarm, I heartily recommend leaving the final drive off so it's lighter, and install it afterwards.  And then I learned that the swingarm doesn't like to go straight in, but instead tip it up-and-in at a strong angle such that the brake-side swingarm pivot bearing goes into the pivot-pin pocket on that side of the frame...in this way, using the depth of the pocket makes it such that the whole swingarm just pivots up and into the frame without any fuss at all.  Have the pivot pins handy so you can put them in without dropping the swingarm on the floor.  (thank heavens for this forum and "search", btw)

We're now entering the "finished carpentry" stage, which in my view always takes the longest if you're going to do it properly.

First, he's starting to look like a motorcycle again...



The tedious business of what has to be installed before what is now in play.  Starting with the rearsets and shift lever.  When I got the bike, the p.o. had bent the left hand rearset way back - I had thought it was to clear the Dunstall silencers with no h-pipe...that put the flare of the muffler really far forward. Thanks to Charlie I have an h-pipe now, and the silencers are now going to sit further back - once I repack the silencers and make brackets noting that the mufflers were unsupported previously and just hung cantilever off the back of the down-pipes. (...sigh..)

However, I still had to do a lot of messing around with shims and spacers to get a rearset+shift position that works.  What's shown is pretty workable with some but not terrible clash; I don't like all the spacers and on downshift to 1st the shifter just skims the rearset and the pipe and will leave wear marks eventually.

Does this look right to you all, and any tips on getting this area to work nicely?  The link from the shift pedal-rod bell-crank to the gearbox is shortened as far as it will go - possibly if I pop the gearbox side lever off and hop one spline, I can get more adjustment back and then 1st->5th will all happen *above* the rearset?  Since it was messed up when I got it, I don't know where this lever is supposed to sit naturally and whether the shifting happens on both sides of the rearset or only one side.

I'll ride this as-is, but if I can clean it up, great.  I also see that the cap-screws are too short now, and nylocs are too tall - so again, a wierd fastener situation here that I have to rectify.



Post-post edit: I popped the arm off the gearbox and rotated it 1 tooth - now 1st->5th is entirely above the footpeg, and I was able to pull 1 turn out of the pedal->gearbox link as well.  I tried taking one set of the spacers out and the shift lever would still hit the footpeg, so with all the spacers in, the shift lever has full travel and hits nothing.  Still not sure this is right, but happier with it.

[cmice]

Brief diversion from muffler packing (grumble, grumble) and an aside on petcock gaskets.  Every piece of rubber on this machine is petrified, so it's all getting replaced.  Bruce Giller is kind and crazy enough to make replacement viton seals for Orlandi (and other) petcocks https://www.thisoldtractor.com/moto_guzzi_loopframe_petcock_gasket_kit.html.

Getting them apart is pretty easy, getting them back together again takes more technique since there's a pretty strong spring inside there that provides pressure on the sealing surface, but it fights you when you try to put the valve body back in.  You have to press down and turn, whilst avoiding bending the bat-handle which is the shutoff lever.  I found that some organic "soft-jaws", and an adjustable wrench can be utilized thusly to both push down and turn the cap until the threads grab and you're home.

[cmice]

Ok - lots to share.  First, choke plungers...my choke plungers are good, but the rubber is petrified.  Bruce was willing to also punch out some viton slugs to fit in the choke plungers.  Will update once we're running and he may add these to his inventory of parts he can supply.


There continues to be a never ending list of things to strip, clean and paint.  The shift rod is chromed, but the brake rod is not.  I mainly took the photo to keep track of how it was assembled so I can reassemble it.  This gets stripped and painted.


Same for the fuse cover - had big holes in it, so epoxied them up and this will get painted too.



The tire guy had a real wrestling match getting the old Flinstone tires off the rims (date code was 1978!). He had to use sticky weights because he had run out of spoke weights.  Any advice or opinions on stickies vs. spokes, and is it worth swapping these out?


Speaking of tires, the new one (Dunlop D404s) are wider than the ones that came off, and that posed fun for the reaction rod for the rear brake assembly.  Not the clearest of photos but if you know what you're looking at I think it will be clear.  Fabbed a spacer to kick the reaction rod to the other side of the tab on the swingarm and make room for the tire, but too far and you clash with the center-stand when it swings up.  Fiddling with this took a while but I think this will work just fine.


Brake rod cleaned, painted and installed.  This is another lesson in "things have to go together in a certain order or else" - with everything removed, the frame looks so open, but as you start to load the parts back in, it's surprising how quickly the space tightens up.  The shift rod and rear brake rod seem to want to go in at the same time. So pull the rearset brackets off and do it again this time with the rear rod in place too.


So where are are we now...


Wiring is back in place, net of the gage cluster.  Got the tank fitted so I could make sure wiring and cables route correctly.  Throttle cables took some fiddling but they're happy now.  Then I learned you can't fit the front fender with the front wheel in place (again, order matters) so I pulled the front off and mounted the mudgard today.  I still need to repack the other Dunstall silencer, I've been putting that off but now's the time.  With the other one packed, I can make brackets and then paint those along with the rear brake switch bracket and a few other bits and pieces.

Getting close to being able to start him up.  Home stretch I think.

Question for the collective - as I'm putting the handlebars back together, I'm curious how the OEM switches are retained on the bars?  The kill/start cluster by the throttle specifically?  As it sits, the switch sort of floats around on the bar and it looks like it gets clamped down with the front brake master cylinder, but there's no clear provision that this is how it's supposed to be.  Any suggestions?

[Antietam Classic Cycle]

Your mufflers appear to be Bubs, the long versions. I had them on my first Convert and a G5 after that, they sounded great.  They were meant to mount directly to the header pipes, at least on those models.

On the throttle side, the switch is held in place by the throttle, on the left side the switch is retained by a locking washer.



IIRC, the last time I needed some, I found them at McMaster-Carr.

[cmice]

Your mufflers appear to be Bubs, the long versions. I had them on my first Convert and a G5 after that, they sounded great.  They were meant to mount directly to the header pipes, at least on those models.

Nope - these are Dunstall Decibles.  They are kinda ridiculous - 31" long and the flare out quickly from the flange which is what caused all the fooling around with the forward footpegs and shifter as the flare got in the way of the levers when put all the way forward onto the header pipes.  With the (your) H-pipe installed, that shifts them back about 6-8", and when I push them all the way forward I can get them inside the rear tire.  I'm not thrilled with the setup, but I think it's workable for now.

On the throttle side, the switch is held in place by the throttle, on the left side the switch is retained by a locking washer.



IIRC, the last time I needed some, I found them at McMaster-Carr.

Not sure I fully understand - the throttle keeps the switch from pushing off the end of the bar, but doesn't stop it rotating *around* the bar.  On the left side, the brake m/c bar-clamp stops it from sliding torwards the steering head, but again doesn't stop it rotating around the bar and I'm not sure what the locking washer does in this case?

[Antietam Classic Cycle]

As I remember it, there should be a "lug" on the switch housing that fits into the clutch perch. Seems there was something similar on the right side as well. Been years since I fooled with those original switches. They're really the worst ones Guzzi ever used and best chucked on ebay (those from my Convert sold for $300!) and replaced with something better.

[cmice]

Yesterday and today were big days.  Engine and gearbox is done, front and rear brakes are done, front and rear suspension is done, exhaust and mufflers are done (only minor bloodshed repacking the 2nd muffler), wiring is nearly done.

Speaking of wiring, let's rig up a battery (see the epoxy and painted fuse cover)...



Turn the key and see what we see...



So, pretty good actually!  The Wixom fairing has to be connected to complete the circuit for the lights - more on that in a minute.  But this seems like progress!

The license plate lamp isn't coming on except when the hibeams are on. And when the hibeams come on, there's a modulator in the circuit - badly in the circuit.  The dip-dim/hibeam-flash toggles the relay, but the headlamp doesn't requite the gesture. So there's definitely some clean up here to do.  I knew this was coming but still - with a lot of these other jobs done and dusted, working on this shouldn't be too bad.



The Wixom wiring, from Wixom, is actually fairly nicely done - and handy they rivet the wiring diagram right onto the connector.  The splices into the headlight bucket aren't horrible but there is a lone unconnected wire in there. Probably part of the problem.  The headlight modulator and wiring *inside* the fairing is pretty hacked in.  So there's going to be some cleanup here to do.  Still not convinced I'm keeping the fairing, because it is enormous - but it's functional and right now kinda integral to the wiring.