Turn signal replacements / replicas - Civilian Lucas turn signals

The best approach

Thanks to Charlie Mullendore of Antietam Classic Cycle for sending me this information via e-mail. In Charlie's own words:

[I] bought a pair of genuine Lucas signals with long stems from Old Britts, part no. 062060, USD $39.99 each, for a customer's Eldo. Equal in quality to the 36 year old originals, sturdy plastic housing, fiber washer holding the bulb contact. Much better than the reproductions, in this case you get what you pay for!

I modified the stems to match the short originals by cutting them off, machining them down to 0.42 inch diameter and then threading them ⁷⁄₁₆ inch-20.

The worse approach

Not having the original Lucas turn signals and not wanting to purchase NOS or piece together a set of used signals, I purchased four of the common Lucas replica turn signals from MG Cycle. The only problem with the replicas is that they have an 85 mm stem, which the originals never had. I set out to fix this problem. Here's what I did:

• I disassembled the turn signal, removing the stem entirely. The stem is just attached with a nut, so it's very easy to do.
• I enlarged the hole in each turn signal body to ¹⁄₂ inch. Since the signal bodies are plastic, this was very quick and easy.
• I purchase four 12 mm × 1.75 mm × 40 mm bolts (this is the perfect length; any longer and the bolt won't fit inside the body of the turn signal). Using my drill press, I drilled a ³⁄₁₆ inch hole through the middle of each one. The electrical wire will run through this hole.
• I placed one lock washer on the bolt and inserted the assembly from the inside to the outside of the turn signal body (so that the head of the bolt is on the inside of the turn signal body).
• I fastened one nut on the outside of the turn signal body and tightened the assembly.
• I reassembled the turn signal, feeding the electrical wire through my special bolt.
• I fastened the turn signal to the motorcycle, with a flat washer, lock washer, and nut.

Materials used:

• Four Lucas replica turn signals
• Four 12 mm × 1.75 mm × 40 mm bolts
• Eight 12 mm × 1.75 mm nuts
• Eight 12 mm lock washers
• Four 12 mm flat washers

Now completed, the turn signals look very close to the originals.

Note: I've since had some trouble with the screws loosening that secure the bulb sockets to the body of the turn signal. The bulb is grounded through these screws, so it has caused some headaches. As a fix, I did the following:

• I used medium strength thread locking compound to secure the screws in place.
• I ran a separate ground wire from the metal socket (using a small nut and bolt) to a solid ground on the bike.

Note: I also had trouble with the contact point on the pigtail. The contact was mounted in some sort of hard rubber, and the spring behind it - combined with the heat from the bulb and the vibration from the motorcycle - slowly pushed the contact through the rubber and away from the bulb...until contact was broken or intermittent. This even buggered up the contact point on the light bulb. For a fix, I replaced all of the rubber-type discs with hard-fiber discs that came packaged with single contact pigtails (local auto parts store purchase). I only needed to purchase two pigtails because each pigtail came packages with two discs - enough for all four turn signals.