Derby Torx Screw Replacement
 

I have a very small leak from the gasket at the primary case/cover that I need to take care of. At that time, I would like to replace all the OEM Torx screws for the Derby cover. Checking out page 520 of the Harley P&A catalog, they have different sizes available with no pricing. Page 517 has a set of chrome Torx specifically for the Derby but doesn't list a size for a hex equivalent.

Anyone know exactly what size I would need to replace the Derby Torx screws? Not sure if I want to go with these from Harley since they are chrome, unless I want to change out all the primary case/cover hex to chrome too. I guess I should ask about the sizes for the primary case/cover too in case I want to replace those with chrome.

1/4-20 x 5/8 grade 8 for derby cover.

torx
 

I just replaced mine. You don't have to get the chrome ones. The parts department should have the stock ones for $1.05 ea.

Thank you both dawg and indyfjr for posting the information. I think I'll stick with the zink so I guess the sizes for the primary don't really matter right now.

I wouldn't change them - those are some very strong screws, in fact so strong that I've seen them hold fast (when over torqued) and twist my snap-on T-27 bit. Chrome rusts, zinc takes a lot longer for that to happen.

I've never had an issue with the Torx, but thought it was a common complaint here that it's easy to strip the head and that many suggest changing them out to the hex. I just want to be proactive in preventing a problem down the road since that's the kind of luck I usually have when I put a tool in my hand.

That's funny, because that's the same luck that I have when I put a tool in my hand...

I would venture a guess that most that have an issue are either not using the right size bit (T25 is close) and or are using a cheap tool. At one time I had a spare primary with a derby cover that I was getting powder coated. Went to remove the DC and several of the screws were so over torqued that the would not budge. Got out a hand impact and they still would not budge but the had never stripped. In fact, the bond between the bit and screw was so good that the snap-on T27 bit twisted and they still didn't strip. Drilled off the head and I could unscrew them with my fingers - not corroded or stuck, just way too tight. Torqued to spec they are easy to remove.

The ones that had problems with the torx were using a t-25 bit to try and remove a t-27 bolt. Hex has less area for the bit to grab and a smaller diameter of the bit to try to turn the same size fastener, sound like a good idea?

Probably not easy finding a grade 8 hex in that size either.