Shovelhead Clutch Springs

[billpedalino]

After so many years of doing this, I'm embarrassed to say that I'm stumped over a very simple problem which I'm sure has an obvious solution that I'm overlooking. What makes matters even more embarrassing is that I built this bike in the late 1980's and rode it for years!

I disassembled my running 1979 shovelhead about 10 years ago and have finally gotten around to reassembling it for possible sale. Over the years the clutch springs have been lost. Therefore, I ordered a replacement set from VTwin (their P/N 13-0136) to replace H-D P/N 37077-68. Unfortunately, it appears that these springs are too long, but I may be missing something and may be incorrect.

I'm using the original clutch setup that I had in the running machine with 5 friction and 4 steel rattler plates and stock H-D pressure plate and release plate. When I assemble everything onto the hub the springs extend to the height of the adjusters studs and don't allow the installation of the pressure plate and adjuster nuts. My initial thought was that either the clutch hub adjuster studs are too short or the springs too long. I'm using the replacement 5-stud clutch hub that I originally ran in the bike and I checked it and the clutch hub against the stock 3-stud H-D parts that I have in inventory with the same result. I also assembled everything into the stock H-D with the same result. Also note that the installed clutch hub stud lengths match perfectly with the installed OEM stud lengths.

It looks like the only possible answer is long springs, but am I missing something? The VTwin replacement spring free lengths are 1.750" and don't know what later free length is. I know that pre-1968 springs (37077-41) were longer and am thinking that maybe the new set is a mislabeled earlier set.

Has anyone experienced the above?

Thanks...

[ammorest]

Bill, I have NOS -68 springs that measure 1.720.
Dave

[gitguy]

The service manual states that 1968 and later free spring length should be 1 45/64" (1.703") and compression test at 30-38 lbs.

[billpedalino]

Thank you Gentlemen.

[Rubone]

Bill, keep in mind that it is virtually impossible to install the outer spring plate with the springs sitting over the studs. The way to assemble it is to put the pressure plate onto the bare hub, add the springs, put the outer retainer plate on, then use the center adjuster screw and a large diameter washer held in place with the adjuster lock nut to compress the assembly. Set it aside, assemble the clutch with the plates, and then install the compressed spring pack as an assembly holding it with the adjuster nuts to be able to remove the large washer. Then continue with the adjustment.

[billpedalino]

HI Robbbie,

Thank you for responding.

Yes, that's how I've done it for the last 50 years! In fact, I still have (and use) the knucklehead lower valve spring collar that I machined out for that purpose when I was 20!! It hangs on my tool board in a prominent place. Every time I use it I think of of my early day in the business at Gil's Cycle Shop (later Eastern Motorcycle Supply) and of my good friend Gil May (RIP).

It just seemed that these particular springs were a bit more difficult to install. They appeared to have more tension that I recall, even though they're the standard-tension springs. Then again, memory cannot always be trusted these days and as time passes, it seems that I'm a lot more detailed in my work - I question everything.

I assembled the spring assembly yesterday as I normally do and all seems to be ok - I was just second-guessing myself.

By the way, I still have that box of unidentified parts that I'm finding during my inventory and cataloging process . I hope that your offer to help identify them still stands!

Thanks to you all for the input....