Triumph Repair: Spit 1500 Grease Cap, wheel bearing grease, cog railroad

Question
Hi, the front left wheel bearing grease cap on my '75 spit keeps falling off and rolls around in the hubcap while I'm driving. As a result, bearing grease goes everywhere and the noise drives me insane :-).  It sounds like a cog railroad! I have replaced them, and beat the offending cap down with a hammer and have not found success. Do you have any suggestions? How about drilling a small hole in the hub and putting a screw in there to hold the cap in?

Answer
Hi Matt,
There are only two parts involved so you should be able to look at them to see what is wrong. Either the hub is enlarged or split or the cap is too small. Look on the inside to see that the axle is not contacting the cap and that the bearings are not bad. Confirm that there is a small hole in the center of the cap so pressure can not build up from the lube getting hot and that the bearings are not over packed with grease.
The cap should be tight enough that it requires a plastic hammer to drive it on or a hammer and screwdriver on the edges to drive it on.
If it is tight, it can't fall off unless it is forced off.

Howard