Size of Allen Bolts on Road Glide

[stagrider]

Well, having looked after a 1999 FLTRI Road Glide for the past 6 months it has now been sold to me for a good price and I'm delighted with it. Just received a service kit and set about the oil changes today. Managed to change the engine oil and filter ok but when I went to do the gearbox I found the Allen bolt is a size I don't have. I have 8mm and 10mm but its somewhere between. Is it a 9mm or do Harley's use non-metric Allen bolt sizes ? Also when I changed the oil filter it would have been easy to get my oil filter tool onto the end of the filter if I could have removed the sensor (is it crank position or oil temp or something ?) - but once again the size seemed to be just smaller than the 5mm allen key I have. So once again I have to assume that Harley is non-metric ? Any advice appreciated.

Regards

[1200shovel]

I think you mean Imperial, which HD is.

[softail898]

stagrider,get yourself a good set of A/F (Imperial) Allen Keys. 99% of Nuts and Bolts on a Harley are Imperial so A/F Spanners and Sockets are needed if you want to do a bit of maintainance. Snap On Tools do everything you need and more but they are expensive Many other makers do Imperial but nowhere near the range of Snap On.

Good luck....Pat.

[Chris L]

Or Halfords do a pro range which aint too bad for the home mech,,and yes they are AF. 10mm for battery post nuts.

[stagrider]

Thanks for all the replies. Bike came with a Clymer manual so I'm intending on doing all my own maintenance. I'll definitely have to get myself a set of imperial/AF spanners/allen keys.

Regards
Mike

[grbrown]

This might sound awfully picky, but Harleys generally use American sizes of fasteners, which have UNC or UNF threads (United National coarse or fine). The spanners they use are usually marked AF (across flats) in simple fractions of inches.

What I would call Imperial are the British Standard Whitworth thread series BSW or BSF (coarse or fine), plus BSC (cycle, or very fine), which use a different set of spanner sizes. These are marked with the diameter of the thread they relate to, not the width of the bolt or nut and are not interchangeable with what we often simply call AF (American).

The Imperial/British and American spanners do coincide in spanner width at large sizes, but not the smaller sizes we commonly encounter on Harleys. For old British bikes you will need Whitworth spanners, but for late 1960 and onwards, both Whitworth and American. Doh!

However, this query started with allen screws, for which the same set of hex keys will fit both Whitworth and American!