Clutch lever return spring

for those with Series MM sidevalve cars produced between September 1948 and February 1953
manlyvaleaussie
Minor Friendly
Posts: 68
Joined: Tue Mar 20, 2018 10:41 pm
MMOC Member: No

Clutch lever return spring

Postby manlyvaleaussie » Wed Jan 05, 2022 5:50 pm

Attached is a copy of the clutch schematic for my Series MM, please note part number 29, spring - clutch withdrawal lever, I have 3 gear boxes and none of them have this spring so I asked around and nobody has ever seen one, I'm sure it was replaced by the return spring that is attached to the relay to clutch lever link on my vehicle where part number 41 is shown. However my enquiring mind won't give up quite that easily and so I wrote to Ian Harris, his reply is that it is probably used on the Series E Morris 8 and would have a part number of X15605. He doesn't have a MM parts list and asks if I can confirm this, of course I cannot but wonder if anyone can confirm Ian's idea.
Best regards,
Paul Follett manlyvaleaussie
Attachments
Morris Minor clutch diagram.jpg
Morris Minor clutch diagram.jpg (495.09 KiB) Viewed 336 times

philthehill
Minor Maniac
Posts: 9511
Joined: Thu Jul 19, 2012 12:05 pm
MMOC Member: Yes

Re: Clutch lever return spring

Postby philthehill » Wed Jan 05, 2022 7:50 pm

The spring item No: 29 should be fitted. Its fitment ensures that the carbon thrust is held away from the clutch thrust pad.
The spring item No: 45 cannot be relied upon to hold the thrust away from the thrust pad. The clearance between thrust and thrust pad is at a minimum 1/16" so the thrust must be held away from the thrust pad and the coil spring is effective in doing that.
Just because other gearboxes do not have the spring does make it right. The coil spring must be fitted and working.

The coil spring item No: 29 is also shown in later schematic B1560. Issue 2. 54936.

You can see a similar coil spring fitted to the Morris 8 clutch release shaft in the link below.
https://www.ebay.co.uk/itm/154773786589 ... Sw62thP6wA


sirrom918
Minor Friendly
Posts: 51
Joined: Tue Jan 17, 2017 5:45 pm
MMOC Member: No

Re: Clutch lever return spring

Postby sirrom918 » Thu Jan 06, 2022 12:47 am

Hi Paul,

I can confirm that the Series MM Parts List shows part number 29 (Clutch) Spring-Lever to be X15605 same as the Morris 8 Series E. However LHD Series MM cars were X15631. In the 'Remark' column it mentions that these lever springs ended at Engine Number 38423.

Note that the gearbox shown in Phil's ebay link above is the earlier (late 1934 to late 1938) Morris 8 Series 1 / Series 2 three speed gearbox and not the 1939 to 1948 Series E four speed gearbox.

philthehill
Minor Maniac
Posts: 9511
Joined: Thu Jul 19, 2012 12:05 pm
MMOC Member: Yes

Re: Clutch lever return spring

Postby philthehill » Thu Jan 06, 2022 8:48 am

sirrom918
Thank you for the clarification above.
The link was not about the gearbox but about the spring. The photo in the link was the only one I could find with the spring intact and on the shaft.
Can you clarify - was the return spring discontinued for L/H drive cars only at engine No: 38423 or was the spring discontinued for both L/H and R/H drive cars.
Phil


sirrom918
Minor Friendly
Posts: 51
Joined: Tue Jan 17, 2017 5:45 pm
MMOC Member: No

Re: Clutch lever return spring

Postby sirrom918 » Thu Jan 06, 2022 6:08 pm

Hi Phil,

Here's a scan of the page - it certainly appears to show that the return spring was discontinued for both L/H and R/H cars at Engine No. 38423. I've no idea why that was.

The only reason I mentioned the earlier three speed box photo in your ebay link was that although the return springs appear more or less identical, the M8 Series 1 and Series 2 three speed box return springs carry a different part number X15198.

I agree wholeheartedly with your earlier comment to Paul that the coil return spring must be fitted correctly and working.
Screenshot 2022-01-06 at 17.28.20.png
Screenshot 2022-01-06 at 17.28.20.png (752.99 KiB) Viewed 260 times
Jeff.

manlyvaleaussie
Minor Friendly
Posts: 68
Joined: Tue Mar 20, 2018 10:41 pm
MMOC Member: No

Re: Clutch lever return spring

Postby manlyvaleaussie » Sun Jan 09, 2022 7:52 pm

Phil and Sirrom,
thank you for this great information, I believe I can now see clearly what happened, check out this idea and give me your thoughts. The photo of the Morris 8 gear box with the spring backs up Ian Harris's information with the spring number being X15605, this of course was for a RHD car and it was continued for the early Series MM but then came along the LHD drive Series MM and they had to make 2 different springs until after engine number 38423 someone figured out that with a modification they use just 1 spring for both RHD & LHD cars, a little savings here & there can add up to big savings overall. My car is engine number 174055 and please see the attached photo of the clutch linkage, the silver coloured spring is number 45 in the schematic and it only returns the pedal but the black coloured spring does not show in the schematic as it was the modification to replace the spring number 29 in the schematic and so was used for both RHD & LHD cars after engine number 38423. This spring seems to be working as designed as if you look at the white marks on the gear box where the clutch shafts enters, the 1 nearest the rear is where I marked the shaft in it's fully retracted position while it was out of the vehicle and at this point the clearance between the carbon thrust and the pressure plate is between 1/6" & 1/8" and now assembled and free travel adjusted to 3/4" the spring is pulling it to that mark. I have contemplated replacing this spring with one of greater tension just to be on the safe side, what do you think and if you ever run across the original spring for the LHD cars as up to engine number 38423 I would love to have it, I will write to Ian Harris again now that I have this additional information. Again, than you for your help and I look forward to comments and advise.
Regards,
Paul Follett. manlyvaleaussie
Attachments
DSC01695.JPG
DSC01695.JPG (185.07 KiB) Viewed 182 times

philthehill
Minor Maniac
Posts: 9511
Joined: Thu Jul 19, 2012 12:05 pm
MMOC Member: Yes

Re: Clutch lever return spring

Postby philthehill » Mon Jan 10, 2022 9:15 pm

If the spring is doing the job it is intended to do I would leave as is.



Who is online

Users browsing this forum: No registered users and 2 guests