1956 Matchless 350 leaking

General purpose topics/chat goes in here
Locked
Ezmerelda1
Posts: 18
Joined: Mon Mar 29, 2021 2:47 pm
Location: Lancs UK

1956 Matchless 350 leaking

Post by Ezmerelda1 »

I have a 1956 Matchless 350 and there is a bad leak coming from near the centre stand. I presume it's coming from the chain case cover but can't see where it's coming from properly. What do you think? Also are they hard to replace? Thank you in advance? Also which are the best gaskets n where from
Mick D
Posts: 2886
Joined: Mon Mar 24, 2014 5:44 pm
Location: Aberdeenshire

Re: 1956 Matchless 350 leaking

Post by Mick D »

Hi

It could be coming from the crank case breather tube and be the result of wet sumping due to not running the engine for a while. When was the last time the engine ran? What is the oil level in the primary chain case?

Regards Mick
User avatar
dave16mct
Member
Posts: 3234
Joined: Mon Jan 01, 1990 12:00 am
Location: LANCASHIRE UK

Re: 1956 Matchless 350 leaking

Post by dave16mct »

There are a few possibilities in that area. (If it's not Mick's answer above, just seen that) The hole in the back of the chaincase where the dynamo and gearbox mainshaft go through. Check the oil in the chaincase, it should only just touch the bottom of the chain or you'll get leaks here. If the chaincase itself is leaking there's an improved seal from the club which works well and is easy to fit. The other one is much more difficult, the gearbox main output seal (behind the clutch). You'll have to get right underneath with a torch and clean it with rag. Observe where it comes from when on sidestand. The whole chaincase side has to come off to replace the seal (also sometimes the spacer it runs on).
Dave.
Ezmerelda1
Posts: 18
Joined: Mon Mar 29, 2021 2:47 pm
Location: Lancs UK

Re: 1956 Matchless 350 leaking

Post by Ezmerelda1 »

Hi Mick n Dave thanks for the help.
The engine has been run recently. I have had the bike about a month and have been tidying it up a little bit. But it has always leaked. I've changed the gearbox oil and topped up the engine oil.
Didn't know I had to top up the primary chain don't know where the top up is? Sorry I'm being a bit thick but I'm having a go😁
SPRIDDLER
Member
Posts: 8542
Joined: Wed Sep 01, 2004 1:00 am
Location: WEST SUSSEX UK

Re: 1956 Matchless 350 leaking

Post by SPRIDDLER »

Ezmerelda1 wrote:Hi Mick n Dave thanks for the help.
The engine has been run recently. I have had the bike about a month and have been tidying it up a little bit. But it has always leaked. I've changed the gearbox oil and topped up the engine oil.
Can you give a clue as to how much and over what period of time the oil is leaking? A few drips? A spoonful? A puddle?
How much oil did you put in the gearbox? If the oil coming out is clean it'll be from the gearbox.
Didn't know I had to top up the primary chain don't know where the top up is? Sorry I'm being a bit thick but I'm having a go😁
The Owners Manual for your bike can be found here:

http://archives.jampot.dk/book/

Gaskets and almost all spare parts are available from the club:

http://www.amoc-parts.com/store/comersu ... oducts.asp

No such a thing as 'thick' Jim, we've all come across problems for the first time ;)
'There is a tide in the affairs of men
Which taken at the flood............'
Ezmerelda1
Posts: 18
Joined: Mon Mar 29, 2021 2:47 pm
Location: Lancs UK

Re: 1956 Matchless 350 leaking

Post by Ezmerelda1 »

It leaks a few drops after a run. Table spoon but if I leave it a few days it'll leave a streak about six inches long. I filled the gearbox up to its proper level. Thankyou
SPRIDDLER
Member
Posts: 8542
Joined: Wed Sep 01, 2004 1:00 am
Location: WEST SUSSEX UK

Re: 1956 Matchless 350 leaking

Post by SPRIDDLER »

If you had to put a lot of oil in the gearbox it may have been because of a leak. If the leaking oil is fairly clean it'll be from the gearbox as even fresh engine oil goes black 'ish after the engine has been run for a few minutes.
I think the most reliable way to go is to give the underneath and the likely areas a good clean in order to identify where the oil is leaking from as it could be for any of the reasons that others have mentioned.
Almost all of these old bikes lose a bit of oil.
'There is a tide in the affairs of men
Which taken at the flood............'
Locked