Box of bits assembly of 1955 G80S

[RobC_LAPSED]

Thanks both.
I'll shift that gearbox adjuster over to the other side.
Back down the workshop next to have another look at that gearbox!
Rob

[RobC_LAPSED]

I had to strip down the B52 gearbox. The sliding gears were well and truly gummed together with what looked like solidified grease! It took a soft mallet to free them! I thought these should only have oil in them, later boxes anyway? The oil ways in the bushes and oil holes in the gears say that to me, grease would just block them up!

I think most of the major parts are ok so I can order the smaller parts from the club. It rather annoyingly doesn't have a control quadrant spindle bush (20-3-1). Any ideas where these could be available from?

I'm a bit surprised to find I have a 4 plate clutch and corresponding 9 7/8 inch thrust rod, as its a 55 G80S! I'll have to use this for now I think, are there problems associated with this?

The thrust rod that I have has a cup shape at one end and flat at the other. I can see in the parts book that there should be a 5/16 ball at the clutch end, hence the rod's cup end should be there. I also seem to have a cup shape in the cam assembly! Does this mean I need a new cam trust dowel (35-3-4) due to some previous mis-assembly wear, as I assume the flat end of the rod should mate with that?

Thanks
Rob

[Mick D]

Hi

The gearbox should be oil lubricated so clean it all and re-assemble with oil of your choice

If you can't get parts from the Club or AMC Classic give Draganfly a try, (the Ariel GB gearbox is essentially a B52): https://draganfly.co.uk/product-categor ... b-gearbox/

I'd assemble the clutch assy and see how it works before buying any spares.

Regards Mick

[Greybeard]

I'd assemble the clutch assy and see how it works before buying any spares.

Im with Mick on this one. It was obviously working in the condition it was in beforehand so there is every chance it will carry on for a few thousand more miles yet. The clutch is easy enough to get to if it turns out to need more work in the future. Who knows what the future holds? You may decide to move the bike on before you wear it out

Steve

[ajscomboman]

I had to strip down the B52 gearbox. The sliding gears were well and truly gummed together with what looked like solidified grease! It took a soft mallet to free them! I thought these should only have oil in them, later boxes anyway? The oil ways in the bushes and oil holes in the gears say that to me, grease would just block them up!

I think most of the major parts are ok so I can order the smaller parts from the club. It rather annoyingly doesn't have a control quadrant spindle bush (20-3-1). Any ideas where these could be available from?

I'm a bit surprised to find I have a 4 plate clutch and corresponding 9 7/8 inch thrust rod, as its a 55 G80S! I'll have to use this for now I think, are there problems associated with this?

The thrust rod that I have has a cup shape at one end and flat at the other. I can see in the parts book that there should be a 5/16 ball at the clutch end, hence the rod's cup end should be there. I also seem to have a cup shape in the cam assembly! Does this mean I need a new cam trust dowel (35-3-4) due to some previous mis-assembly wear, as I assume the flat end of the rod should mate with that?

Thanks
Rob

I wouldn't be surprised by anything after all this time, grease in these boxes is fine so long as it's the correct grade and a teaspoon of oil every 1000 miles or so. As for the cup in the adjuster screw, the rod sits snugly into it and at the other end where the lifter mechanism is by the filler cap, that's where the ball should be. Nine times out of ten the spring loaded thrust dowel in the centre is totally knackered and the indent is almost a perfect fit to the ball. It should be a square end with no indentation. All easily fixed as the parts are available. Unless the bush is totally shagged I wouldn't be too worried about a little bit of play. In fact a Burman gearbox operates better with play as opposed to everything being a nice snug fit. I had a box come to me that had been overhauled by a very competent machinist who'd converted it to needle rollers and superblend type sleeve gear bearing. It was totally useless! None of the gears would slide under load as the tolerances were far too close. Fortunately the work carried out was to the shafts and not the case. I stripped it used good used bushes 2 very good used shafts and it has turned out to be a very sweet gearbox, play in every component and works smoothly, and it runs in grease!

[RobC_LAPSED]

Thanks all for your tips, very useful.
Draganfly seem to have the bush so that's good. It's missing so I need to get one. I'll get a 5/16 ball and new gaskets then see how the clutch fits/operates after the B52 reassembly.
Rob

[RobC_LAPSED]

Can I call upon your knowledge once again please.
I got the B52 gearbox back together and got this, the engine and forks back in. I quite expect to have to take things apart again if I need to though. This assembly is as much about working out what's missing as it is about how it all fits together. I'm currently sorting the chaincase area after a diversion getting the front wheel spindle out! This leads me to my next questions!

1. I have a dynamo with its sprocket and the holes in the engine plates and nothing else in this area! I can work out the part names/numbers required to fit it from the parts book, but not all seem to be available. I have no idea how these parts look or fit together. Does anyone have a picture of this area or diagram they can share? I'm guessing some of it could be fabricated near to the original design in the shed, with buying some available parts?

2. The previous owner seems to have done work on the engine but there is a rocker box bolt missing, see photo. It's one of the two with a threaded extension. From looking at the parts book, I can see there should be a rocker box stay (I dont have) and stay clip (I have). Am I right that this is what the threaded ends of these 2 bolts are for, being used to clamp on the frame crossbar? I could clamp the rocker box to the frame with the one bolt and a close fitting dowel in the hole for now, but!
Whats your view on the engine running ok with this bolt missing?
I don't think there is any thread in there hence how the bolt got lost! I guess a proper job at sooner or later, is the engine out & head off and get a helicoil fitted and a new standard part? If that is possible? An oversize stud doesn't seem an option as it will mean engine out, for any top end work!

Thanks, Rob.

[Mick D]

Hi

You can remove the head with the engine in situ, which is what I'd do in order to repair the thread properly. I wouldn't run the bike for any length of time without the head steady, (which is just a lump of angle with three holes drilled - easy to make at home if the usual sources can't supply).

Id also replace the bolt fwd RH which is wrong and over length.

Regards Mick

[clive]

http://www.amoc-parts.com/store/comersu ... duct=21102

if you decide to make it yourself the cut off at the top of the apex is necessary so the steady bracket will sit against the clip round the frame.

[SPRIDDLER]

I don't think there is any thread in there hence how the bolt got lost! I guess a proper job at sooner or later, is the engine out & head off and get a helicoil fitted and a new standard part?

Most often the rocker bolt tappings in the head become stripped due to owners trying to stop an oil leak in the rocker box to head joint by overtightening the bolts.
Over time the blind holes in the head collect debris (bits of old gasket, Hobnob crumbs etc.) so that although the bolt feels tight it has merely bottomed out on the debris at the bottom of the tapped hole and prevented the joint gasket from being compressed sufficiently between the two faces. So before tightening the rocker bolts it's a good idea to clean any crud out from the blind bolt holes in the head.