Friday, August 12, 2016

Fiona is back on the road.

I received the repaired gearbox from Richard Winter, aka Bural on SovietSteeds yesterday afternoon.

I had been prepping the garage and area around Fiona with this expectation in mind:

 The '84 R80 Beemer engine's flywheel, cleaned up and
ready for the clutch pack components.

Ready for installation...

Part of the shipment from Bural, along with the repaired gearbox, was this slightly used clutch disk from '87.
It's got the "old" clutch material, now deemed bad for you but apparently longer lasting.  It's believed also the splines and collar are a bit "beefier" in order to withstand sidecar duty.

 The disk came with some minor surface rust which I cleaned up.

 Clutch spring/diaphragm, now sitting next to the flywheel.

 Clutch disk sitting in the pressure plate, both will then go against the clutch spring.

 Compression ring, holding the spring/pressure plate and clutch disk
loosely in place, two bolts with nuts ready to tighten down the compression ring.
Once you have compressed the compression ring, you can insert the mounting
screws in the four open holes, remove the compression bolts and put remaining two
mounting screws to hold everything in place.

 Before applying pressure, you use the tool above to center the
clutch disk on the small divot at center of pressure plate.

 Clutch pack now installed and secured.

 A quick check to make sure the splines are centered on the divot, this divot is
what the clutch actuator rod pushes against to free the clutch disk and
disengage the drive system when needed.

Clutch pack installed, it was time to install the repaired gearbox.  Bural had found a failed bearing at the rear of the main input shaft; possibly caused by mis-installation by PO.  The theory is that when the bearing failed, it caused the old input shaft to wobble slightly, causing damage to the splines both on the clutch disk and itself and eventually stripping the splines from the old clutch disk.

 Gearbox with new input splines

This is how the old input splines looked like

Richard had warned me that he'd found some unwanted "play" in the casing when he was working on it.  So he added some material and welding I believe.  The warning was that I would find the gearbox a "tight" fit when mating it onto the Beemer engine case.

"Tight" was an understatement.  The gearbox must have been quite "out of true" the first time I installed it because that time, it went right up to the engine case, easy peasy, no fuss, no muss.

This time, it would take me over two hours I think to get it to mate to the engine!  Tight fit indeed, a weighted plastic hammer, 2x4 piece of wood, and a crowbar were involved in moving the gearbox into position.

I tightened the four bolts which hold the gearbox onto the engine but I am pretty sure the darn thing would remain in position even without them!


Next fun thing was installing the new type drive shaft and donut onto the gearbox.  Wow, that was so much fun.  Really, it was a massive PITA.  I finally got the donut onto the output yoke of the gearbox and the driveshaft yoke by:

1. first inserting the donut onto the driveshaft yoke.  Not as easy as it sounds, the donut holes are a tight fit and a long screwdriver and cursing was involved.
2. then, pushing the donut onto the yoke on the output shaft.  This took a bit of work, long screwdriver to act as lever/wedge as well.

Note: Must figure out a way to push the swingarms past the rear fender to be able to simply push the donut off the gearbox yoke; and remove the driveshaft without removing it from the driveshaft yoke.

 Above, donut now connecting the output yoke from the gearbox
to the driveshaft yoke.  

Driveshaft connected to the gearbox via the donut, it was time to mount the final drive onto the new style drive shaft.  This proved very easy, though I had to do it twice as I forgot to install the rubber cone that keeps dirt out of the splines where the final drive mates to the new style drive shaft.  Grrrr.

 Using a tie-down strap to pull the swing arm (which has to be unmounted
to remove/install final drive or now, remove the donut) into its mounting point 
so I can insert the large bolts on which the swing arm pivots.

 Using same strap on the right side, anchored on the forward
upper strut and the right-side shock.

 Swing arm mounted up once more, you can also see the drive shaft is
"in phase" with the donut end.

After a minor struggle (turned out to be a bent screw), I got the speedometer cable installed and secured.  This time, at Bural's suggestion, I put some RTV sealer where the cable goes into the gearbox.  The rubber cap that is supplied by URAL is more wishful thinking than something to prevent water from getting into the gearbox.


Fun part number 3:  Installing the clutch actuator lever onto its pivot point.  I am sure there's a trick to it but I always struggle with this portion of the procedure.  You have to somehow push the bottom of the lever in enough to allow the pivot pin to run through it and the mounting points!

 Clutch actuator lever in place.

The rest was easy, reinstalling the air box, hooking up the air tubes to the carburetors after reinstalling the crossover fuel line.  I also installed a new see through plastic drain tube from the engine to the air filter to catch blow-by from the engine.


Finally, it was time to secure the sidecar drive shaft onto the final drive and secure the mounting screws with safety wire:
 The narrow bar is for actuating the 2WD

The pusher wheel and axle went on easily enough, I made sure to install the big washer onto the end of the axle before securing the 22mm nut which holds the axle on the right side; tightened the pinch bolts on the left side and that was that.

Now it was time to fill the final drive and gearbox with appropriate oils.  I'll be draining the gearbox oil in 500 km to get rid of the expected metal bits (look like sparkle) that'll have come off the new input shaft within the gearbox.


After that, run the rig for another 1500 km, drain the gearbox oil again and check for metal bits.  Hopefully there will be less.  500 km after that, for a total of 2500 km is the "break in" period for the gearbox where I cannot exceed 40 mph.

Took Fiona out for a couple of short test drives, perhaps 25 miles or so, she ran well though there were a couple of instances of slipping out of gear.  I had to shift up when it slipped out of gear and all would be fine. It only happened a couple of times so am hoping its just the gearbox settling in.

Got about 1500 miles of 40 mph and under driving ahead of me; perhaps I'll put a sign on the back of Fiona that says: "Limited to 40 MPH".  : )

Very happy with the return of the gearbox and Fiona's seemingly good behavior.  Keeping my fingers crossed that she makes it past the 1060 mile mark, that's when the old clutch disk failed back on 21MAY16.

Update: Bent the tab on the metal plate between the swing arm and the swing arm bolt head that prevents the bolt from coming loose.


Also, added 12 mm worth of plywood spacers under the battery to raise it up enough so that the end of the clutch cable doesn't hit the battery anymore.

10 comments:

Mundo Bravo said...

Great story , thanks for posting this up.

Charlie6 said...

Wish us luck Ed....if this rig doesn't work out, I may got the KLR650 sidecar rig route!

RichardM said...

Where was the difficulty getting the transmission mounted? Getting the spline into the clutch or getting the screw holes lined up. Do you need a special wrench to remove the swing arm mounting bolts? I thought I read that there was a clearance problem getting a regular wrench to fit.

Looking forward to further BMW powered Ural adventures.

Charlie6 said...

RichardM, I am a bit unsure what was causing the tightness of the fit but Richard Winter had mentioned adding some more aluminum to the case edge itself. Perhaps it was also the newer input spline being inserted into the clutch splines, I thought I had it lined up and it would have rotated anyways on the way in. I'll try and ask next time I talk to Richard W.

The screws getting lined up didn't present a big problem. I used them, in fact to bring the two pieces together a bit more.

On this '99 Ural, the swing arm bolts just screw out, they've a slotted metal tab (separate from bolt) which supposedly would prevent them from rotating free, no nut on the inside end.

Regardless, the tightness of the drive train due to the 2WD FD, requires me to unmount the swing arm each time I want to remove the FD. The use of the new style drive shaft, though having beefier splines, is going to add to the PITA factor.

It is, what it is. Let's see is she last longer this time.

Spat said...

Good job C6 glad to hear you got 'er back on the road

Charlie6 said...

thanks Spat, let's see how long she lasts this time.....project motorcycles, what was I thinking?

Spat said...

That project bike was a lot of fun in Moab looking forward to her next adventures

Charlie6 said...

Spat, she was indeed, everyone seemed to have a good time though there were some "moments" I could have done without....

Arizona Harley Dude said...

Seems to be just a bit more than tinkering involved in Fiona. I am finding the dry clutch on Stella to be a slow learning process as it doesn't seem to engage as smoothly as the wet clutch on Petunia. Any tips that might help?

Charlie6 said...

AZ HD....my experience with a wet clutch is limited to the Suzuki DL1000 V-Strom that was my rig for a while, and that one was needing a replacement for wear.

Based solely on my experience with URAL dry clutches, the recommended way is to be methodical in the shifting of gears, they don't like rapid upshifts, preferring a short but definitely interval between shifts. Does that make sense?

Oh, and I've never ridden a Moto Guzzi at all so I could be completely missing your point here.

As to tinkering, yep, there's a bit involved with mating disparate components together, but the added power (or perception of same) came make it worth it. Just have to be patient and break in the new gears correctly.