Thorneycroft 154 Tachometer take off

[Tony Brooks]

1 hour ago, PeterOH said:

Hi @Tony Brooks I used epoxy glue on the spline for the second gear and put a little on the first gear just for good measure. Everything is running smoothly, although only with my fingers spinning the skew gear. You suggested moly grease, but I was wondering if half filling the unit with synthetic oil would be a better option. The lowest positioned gear will splash it around and keep the  unit good for years?? I worry a smear of grease will quickly work its way off the gears and sit in the corners. Or do I pack it full of grease? I also wonder if the engine’s oil will work its way down the skew gear shaft and into the unit anyway. There’s a helical groove in the shaft.  Appreciate your advice on this before i pop the second end cap into place and bolt it back onto the motor.

 

 

I doubt either shaft now has an unworn and effective oil sealing device, although the helical groove in the shaft may be a scroll to return engine oil splash back into the engine. It depends on which shaft has the helical groove. I would fear that oil may well seep out of the shaft holes. I would not be worried about it getting into the engine, but if it worked its way up the cable and into rev counter it would cause problems - probably full scale reading.

 

I suggested molly grease because molybdenum is a very effective dry lubricant, so even if the oily component worked away from the gear teeth, there would still be a degree of lubrication. I would not pack the case absolutely full to leave room for expansion, but I would be very generous with the grease.

[PeterOH]

Hey @Tony Brooks and others, I put the unit back into the engine today and all seems to be working fine. Time will tell. Thank you to the collective thread for all the background info. I shot a couple of vids of the Thorneycroft purring, but the files are a bit too big unfortunately. Pic attached for future reference, of all the parts laid out like a parts schematic. You’ll have to imagine the dotted lines. Beautiful sunny winter days here in Moreton Bay (Queensland, Aust) so time to venture out on the clear waters. Regards