Engine sprocket

[jensendk]

Hi all

Can anyone tell me the size off the collar spacer 021877 In,out and width I am not shure I have the right one and how too fit it.

Engine sprocket is it 19 tooth?

Best regards
Per Jensen

[burrage]

I don't recognise the part number you quote, but the part I have is 023066, which fits singles from 1957 onwards with AMC gearbox and the dimensions are :-
I.D. - 1.015" - clearance on a 1 inch mainshaft.
O.D. - 1.25"
Width 0.265"
The standard sprocket for a 350 with AMC gearbox (starting 1957 model year) is 19 tooth. Sprocket for earlier 350s with Burman gearbox and engine shaft shock-absorber is 18 tooth.

[Triumph-Legend]

If you still are not certain that you have the correct part, speak to Steve Surbey at AMC Classic Spares. He is bound to know exactly what you need.
I had the same problem with a G80 engine. An incorrect spacer had been fitted resulting in damage to the crank case and crank shaft.

[Pharisee]

The spacer you quote (021877) is also used on my '55 18S. I can't tell you the dimensions other than it was an easy slide fit over the crankshaft and the OD was just a little smaller than the hole in the crankcase. It was approximately 1/4" thick. It fitted onto the crankshaft and into the crankcase so that it was up against the main bearing inner ring. The sprocket went on next.
A previous owner of my bike had left it out with the consequence that the sprocket was too close to the crankcase and the dynamo drive chain had worn a groove in the aluminium.

[Triumph-Legend]

The spacer you quote (021877) is also used on my '55 18S. I can't tell you the dimensions other than it was an easy slide fit over the crankshaft and the OD was just a little smaller than the hole in the crankcase. It was approximately 1/4" thick. It fitted onto the crankshaft and into the crankcase so that it was up against the main bearing inner ring. The sprocket went on next.
A previous owner of my bike had left it out with the consequence that the sprocket was too close to the crankcase and the dynamo drive chain had worn a groove in the aluminium.

Yep, That's pretty much what happened on a G80 that I had bought. The difference being that the chain had cut a slit around the front of the boss on the casting and the main bearing had been floating about as the spacer was missing. Oh, how I laughed.
It took a crank rebuild with new axle and a significant repair to the crank case by T&L Engineering to sort out the damage. I must say it has been fine since the rebuild, but it is galling to think that all the damage was cause by careless work by a previous owner. It would only have taken a quick look at the manual and a bit of common sense to have avoided all the damage.
As I have said previously. Do check that you get the correct spacer, also check that the sprocket cush drive parts, spring and retaining cap are correct. Also that the sprocket has not been messed about with.

[56G80S]

That spacer is important as you've mentioned, I changed mine when I put in the AMC in place of the Burman gearbox.

Check that the chain runs are still in line and not risking clashing when you re-assemble as this can be a pain if it happens.

Note use of pan head screwsa rather than the little hex head and funny lock washers. I know a lot of people discard these and use Loctite but they've worked for me over the last 40 years.

Johnny B

[jensendk]

Hi All

Thanks for info on the spacer and sprocket, nice too get help from you...👍

Merry Christmas and happy new year 🎅🎅

Per