MM gearbox query

for those with Series MM sidevalve cars produced between September 1948 and February 1953
Mick Lynch
Minor Fan
Posts: 150
Joined: Sat Sep 12, 2020 9:20 pm
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MM gearbox query

Postby Mick Lynch » Sun Mar 07, 2021 2:17 pm

Few questions regarding the MM gearbox.

Anyone know the correct distance of the flange to the rear housing? I’m asking because there seems to be a lot of oil scroll on mine. Attached photo.
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Also I noticed that there is an opening at 12 o’clock on the bell housing. I have an old pitmans book of the Morris 8 and Morris Minor and it shows some adjustment through a similar opening. Is this a normal feature?
E8B43580-93C0-4A0F-A979-F3CD7A9F237B.jpeg
E8B43580-93C0-4A0F-A979-F3CD7A9F237B.jpeg (1.57 MiB) Viewed 982 times
The gears are bright, not rusted. There is some surface rust on the selectors but this doesn’t interfere with the action. The shafts seem nice and clean, rotate easily with no slogger or play and the shift action is smooth with a satisfying ‘click’. I’m hoping a fresh charge of oil is all I need.

alanworland
Minor Legend
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Re: MM gearbox query

Postby alanworland » Sun Mar 07, 2021 5:48 pm

Doesn't look right, the scroll should not be visible. Just measured my spare box flange to casting end at 57mm (yours looks like 65?)
I would investigate as you can guarantee it will leak.
As for the hole, don't know what it's for but they all have them!

Alan
Image

Mick Lynch
Minor Fan
Posts: 150
Joined: Sat Sep 12, 2020 9:20 pm
MMOC Member: No

Re: MM gearbox query

Postby Mick Lynch » Sun Mar 07, 2021 8:16 pm

Thanks Alan, to make matters worse I cleaned the gunk from the nut and the thing is tack welded to the main shaft.

I can probably grind the tack off with a pencil grinder but what horrors are lurking next. I think the rear bearing might have been replaced with a bigger one (depth rather than circumference).

RobThomas
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Re: MM gearbox query

Postby RobThomas » Fri Mar 12, 2021 8:00 am

On the Austin Seven (pre-war) there is a similar hole for lubricating the release bearing mechanism. Strangely, the Morris 8 gearbox doesn't have that hole in it. Since the hole abuts the sculpted cut-out for the steering rack it hay be a feature of the modification process to fit the Minor. If the sculpting risked breaking through the bellhousing then it may have been preferable to make a decent sized hole to prevent the risk of cracking?
Cardiff, UK


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