Rear chain guard removal

[Pete A10]

Having followed this thread and looked at the B40 Parts book I can see the confusion and why my solution may not be viable in your situation. I did not have a captive nut on the inside of the chainguard just a quarter inch clearance hole through the chainguard, so I had to be able to hold both the head of the bolt and the nut to tighten it up. Don't know why it should be different as when I got the bike it was very original and unmolested so presumably the chainguard was an original factory fitted part. It was very early model - manufactured December 1960 so maybe they changed the design to something easier to work on in later years. If yours is a captive nut it will be easier to remove the bolt into the chainguard rather then the one into the swinging arm.

[Phil C]

Bernie, I was just wondering if you got time to do this yet?   Phil.

[TTJOHN]

Captive nut should be on the inside of the chain guard, if it doesn't have one weld one in place, chain guard can be removed with care without taking out back wheel or mudguard, bracket stays fixed to the swinging arm. HTH

Regards TTJohn

[Phil C]

I eventually managed to undo the chainguard, but can't actually remove it without removing the back wheel and/or (not sure) mudguard. But anyway I have been able to move the chainguard enough to know that I've been wasting my time: the reason I wanted to remove it was to enable me to see the inboard side of the hole where the alternator wires leave the primary chaincase (looking to identify the source of a leak), but I still can't see it even when the guard isn't in the way. So I might as well fix the guard in place again. Sounds simple, but isn't. As I feared, refixing is even more tricky than removing. I have a loose chainguard, an L bracket and two hex-head screws to get in place in a very tight space. I think it would be much easier with the mudguard off. Remember I'm a novice: is the rear mudguard easy to remove?  Thanks again for your help so far. Phil.

[berniej]

Hi Phil, only just seen your post from Jan - I haven't had a look at this yet - it's been too wet and cold to get out in the workshop but I will be attempting to fit the chainguard when the weather warms up a bit. I think that if you can get the bike on a ramp with clearance under the rear wheel the it shouldn't be too difficult to remove the seat and the rear wheel which should expose the nuts and bolts that hold the rear mudguard in place. Mine has only recently been rebuilt so I'll probably do that to fix the chainguard as I know that the threads are clean and so it shouldn't be difficult to strip down.

Cheers,
Bernie

[Phil C]

Thanks Bernie. I don't have a ramp but hopefully a piece of wood under the main stand will raise the rear wheel an inch or two off the ground and hopefully that will be enough for me to take the wheel off, then the mudguard off. Anyway, we'll see.  I'm learning slowly as I go along.   Phil

[Phil C]

Taking the rear wheel off, I obviously need to disconnect the speedo. I've undone the hex on the front of the speedo gearbox. Then what do I do?    Phil.

[Rog1]

Phil,

have you considered using a mirror to try and spot the leak?

Roger

[Phil C]

It has crossed my mind to use a mirror. Maybe I should get one.

[Pete A10]

Re the oil leak. The hole where the alternator wire exits the primary chaincase should have a rubber grommet on it. They usually disintegrate over time. If the bike has been apart it is possible that a new grommet was not used - they are an absolute pain to fit. If there is no grommet it will leak oil.
The B 40 also has a "chain oiler" built into the rearmost primary chaincase bolt. The nut on the inside has a has a brass body with a small pipe coming off it which is meant to drip oil on to the chain. There should be a fibre washer between the nut and the primary chaincase, if not it will leak. I found that to control the flow of oil to a minor drip just enough to oil the chain I had to squeeze the tube almost closed otherwise it runs out much too fast - giving the impression of a serious oil leak.

[Phil C]

There is a grommet but I wonder if it might be leaking. Some time ago a dob of silicone on it appeared to reduce - but not completely stop - the leak. I'd like to renew it but, as you say, that would be a pain. I looked into the chain oiler issue ages ago - can't rember details but was fairly sure that wasn't the problem.

[Blackthou]

Hi,

Sort of arrived at this thread due to my own issues. A couple of weekends ago when it was peeing down, I started to finish off re installing my head as I'd had it off for an overhaul. I thought I'd polish up the oil feed pipe to the rockers. All I needed to do was disconnect it from behind the oil tank but couldn't get to it. Took the side panel off and the frame behind it.

Still no joy so to cut a long I then proceeded to remove the battery, central cover with switch and oil tank and finally disconnected it. This gave me clear access to the chainguard and the fact it wasn't secured at the front bracket. I also decided it was a good opportunity for a clean up.

Couldn't get the chain guard off so then removed the rear wheel. Got everything off eventually. Stripped the rear wheel. Rubbed down and sprayed both centres and polished up the aluminium which had a few gouges in it. Also stripped and clean the rear brake shoes etc.

The front of the chainguard wasn't secured as the bracket was too short and there was a hole in the chainguard as Pete A10 said. Mine also is a December 1960. Perhaps they were having a Christmas P*ss up and forgot a few.

Anyway, made a new bracket and put it all back together this afternoon as it was weekend raining again after a hot week. Without everything else in the way access was easy. Again as Pete said, the chainguard must be the first thing on the bike when they start to build it. No wonder it caused so much consternation to others. Just got to clean up the oil feed pipe and then reassemble the centre panel etc. back where I was a few weeks ago.

[Phil C]

Well done Rick, you've been busy! Phil