TR4A Clutch Push Rod Location In Cross Shaft Lever End

[RAHTR4]

I have now reviewed another Standard Triumph Engineering Change Sheet, dated 15th January 1965, which instructs specific changes were to be carried out to the clutch operating system of the TR4A.

EC / 7661 – Dated 15-01-65

Description Of Change :

To make Clutch Hydrostatic in operation and to prevent overstroking the Clutch

Production Instructions

A.1. Incorporation. Retrospective action to be taken.

Note : - Slave Cylinder Push Rod must be fitted to the Bottom Hole of the Clutch Operating Lever to prevent overstroking the Clutch

Plus the following in the three adjacent columns : -

PART No.               ACTUAL DETAILS AFFECTED             PAGE No.

                               ITEMS DELETED -

106347                   Anchor Plate                       1 off             1702

43929                     Spring                                 1 off             1703

Firms Affected – Canley.

I gained my basic knowledge of this change from the Moss Catalogue, which from day one has always been my go to publication, this in preference to anything else, because it contains clear illustrations and far more detailed information than any of the Factory publications.

However a different view is given in the Moss Catalogue which states : -

There are three holes in the clutch cross shaft lever end.

All 4 cylinder TR’s should be connected from the slave cylinder to the CENTRE hole, the other two are for use on different Triumph models

I must point out that I am not throwing stones, far from it, because I only have a small number of Engineering Change sheets relating to the TR4A and readily accept that different scenarios may well have been published which are now lost.

In addition Bill Piggott tells us that the first TR4A rolled off the production line on 5th January 1965, and this Engineering Change being issued on 15th January 1965 including a stated A.1. Incorporation, so my thoughts are that it must have been implemented on an urgent basis and subsequently as larger numbers of cars came into daily use it was possibly the Triumph Service Mechanics who found the centre hole location as being the best to prevent overstroking happening..?

Regards, Richard

[Z320]

He Richard,

what happens when you overstroke the slave cylinder or clutch cover, please?

IMO - nothing.

From the holes it is the best to use the one that guides the push rod in line with the piston.

On my 4A this is the middle one.

All other holes push the piston sidewards up or down and cause it needless grinding on the bore surface.

Ciao, Marco

 

[RAHTR4]

Hi Marco,

Thank you for the response, as usual very logical and sensible thoughts.

However I am a novice in these matters and really do not know a precise definition of overstroking in this contexed. 

Regards, Richard

[BlueTR3A-5EKT]

Interesting 

As one of the people involved in writing the tech tips in the Moss Europe spare’s catalogues.   
Had I seen that EC sheet the info would have been included.    
Along with Marco I agree a straight line push is a preferable assembly.