Does anyone know the bolt length of the derby cover bolts and primary inspection cover bolts?

 

I'm pretty sure they're 1/4".

 

3 different sizes. ( and it's possible they've changed from year to year)

the primary cover has short and long bolts, the derby has even shorter.

I'm guessing you are changing hardware? just pull one of each and measure- good time to change the derby to allens from torx

mike

 

My bad. I thought your question said size. Now I see it says length. Did you edit that are am I losing it?

 

just put new socket head cap screws on today mine is a 05 egc bolt size is 1/4-20x5/8 for both covers.

 

There 1/4" x 20 x 1/2" Grade 8

 

ditto

replace with stainless from McFadden-Dale. I prefer SHCS over the button heads. If you want you can polish the ribs off the heads

 

Yeah, that was my intention, to use the allen head bolts. My bike is also an 05. Guess it wouldn't hurt to pick couple different sizes (1/2" and 5/8").

 

VERY late to respond to this (and sorry for reviving such an old thread), but this site is what came up when I googled to find out what to do about those stupid torx screws on my sportster's clutch inspection cover. So thanks for all contributions above, it helped a lot (even thouh I was left confused about a proper replacement screw).

I measured the screws on mine (2008 Sportster 1200XL) and they are DEFINITELY 1/4"-20 5/8"

I will DEFINITELY replace them with proper stainless hex/allen button screws.

While I'm bitching about Harley's silly use of crappy fasteners, I'm also pissed that they spec the torque in IN-lbs (when all other specs in the world, and all torque wrenches that I own, are specified in FT-lbs). It means that the previous owner incorrectly torqued these screws to 12 times the intended value. Sheesh... The spec says 84-108 IN-lbs, which means a *very* low torque of 7-9 LB-lbs (i.e. not much more than finger tight).

No wonder there are thousands of complaints about stripped torx screws on Harleys...

 

If you think about it hex and allens, are 3/4 of the way to being stripped. Torx has the most surface area. Lots of guys have screwed up by using T25. Also button head bolts torx or allen are not that deep.

I put anti seize on derby and inspection cover, and not a problem.

I have thought 12pnt might look cool and give you plenty of bite.

If you convert to SS remember to use antiseize. Also that it changes torque values. I believe primary calls for loctite. Not sure if that will protect you or not.