Anybody know what the length of the clutch push rod in a 1969 A65 should be? My clutch was at the limits of its adjustment at both the lever and the pressure plate so I have replaced the cable, clutch plates and the push rod which looked worn. The existing rod is 11" long and the replacement is 11-13/16". While the old rod appears to be too short the new rod appears to be too long.
Should I grind the new one down to the correct length? Suggestions? Thanks, Jim
I have measured push rods as well as clutch rods before and they vary. Cannot imagine the quality control problems BSA had in those days as these are incredibly simple things to control. If the push rod is too short the grub screw can't take up the slack, and if it is too long it sticks out too far and hits the cover. If your plates are fairly new (full thickness) check by trial and error to get it right.
And the ASTM Handbook says to quench is oil. Water quenching small diameter rods is too severe and can lead to cracking.
Whichever medium you use it is even more important to swish the rod around to prevent gas bubbles sicking to the surface and creating unevenness i the hardless.
I had an engineer tell me the same thing. He basically refered to anything that needs hardening to use this method for this reason.
Copper gaskets etc, only use water to help remove scaling.
Ah if it's in the ASTM it must be gospel
I'm really disappointed that my pushrod hasn't cracked since I put it in water
I bet it doesn't make a rats a55 difference what you put it in
But I'll let you techno-buffs deliberate this further!
Me I'm off to start a new 'Oil Thread', "What shall I use in my gearbox"? Washing up liquid or Hypoid 90? My mate told me to use 'Fairy Liquid' (don't use the Tesco Value stuff it's rubbish) Fairy Liquid, reduces friction and keeps the cogs "sparkly clean", well that's what it says in the Handbook!
Last edited by DickDastardly; 08/11/118:07 pm.
Re: Clutch Push Rod
#389097 08/11/118:36 pm08/11/118:36 pm
If it silver steel you can use either water or oil depending on how hard you want to get the ends.
I used water quench when making things like production drill bushs which needed to be like bearing hard.
But for things where brittleness is an issue (like the push rod) I would definatley go with oil quench. The thing that makes the biggest diffrence to hardening silver steel is how hot you get it and how long you hold it at that heat for. Discussing quenching media is pretty pointless without a material spec , exact temprature of heating and lenght of "soak"
"There's the way it ought to be and there's the way it is" (Sgt Barnes)
Thanks guys. The existing pushrod was mushroomed at one end and an additional ballbearing had been added on the lever side to try and make up for the wear. It was now at the point where even at the full limits of the cable and pressure plate adjustments it would creep in gear when hot. The SRM description for customizing is helpful. The diameter of the new rod seems fine. Will let you know how I make out.