Clutch actuation shaft gets hot on 1938 Model 50

Previously gary_hawksworth wrote:

My clutch has been dragging badly when when its been running for aver 10 miles or so.

I have replaced the gearbox bearings and clutch plates which have improved the normal action but still getting the problems when its hot. I noticed that the shaft running through the gearbox appears to have dis-coloured at one end due to heat.

Can anyone confirm if there should be a ball bearing between the shaft and the mushroom? I have tried putting one in but the mushroom sticks out too far even when moving the worm drive fully out. Has anyone had similar issues? Is there more than one shaft lenth?

All ideas welcome.

The discolouration you notice on the pushrod will be from the hardening of the ends by heat treatment.

Do you have notches on your clutch drum and center that could prevent your plates moving freely? If so these need to be filed out

There are a number of mainshafts which will fit in the 'Doll's Head' box and I believe that those for the 'Laydown' box are a different length.

Originally, the mainshaft was listed as part no. 3318 with 3319 for the Inters (these were 3/- odd dearer). However, this 3319 part was later used for the WD16H as well so the difference is probably one of hardening rather than dimensions.

The spare mainshaft that I have here measures 9" using a rule (too long for my calipers).

All the pre-war boxes used the same clutch pushrod - part no. 3612 and these are approx 7 7/8" long.

I don't have a mushroom to measure but mine is fitted with a ball bearing between the two parts.

Are you using the correct plain steel pressure plate ? Photos of the components might help spot an anomaly.