Fork Woes & '69-'70 Slider Interchangability

[cheezer60]

I'm going to be very thorough in my cry for help; apologies for the book. You all have been VERY helpful in the past; many thanks ahead of time.

I recently picked up a set of forks and shaved sliders that came off of a "running" 1960 panhead. Interestingly enough, they arrived bone-dry and missing all of the dampener components. My only assumption is that the only thing that was running was the previous owner from this troublesome front end. Here's where I'm at:

Had the slider bushings honed, bought repop dampener assemblies & gaskets, and had 6+ tubes shipped from Forking by Frank. Good to go, right? No.

When installing the dampeners, I realized the Franks tubes had the snapring groove machined a bit further up into the tubes (than the original), so that the lower bushing on the dampener assembly wouldn't quite fit under the snapring. I had a shop take a hair off of last dampener bushing to fit them in snug.

Now I have the legs reassembled and installed on the bike, but they are leaking at the dampener stud. I've tried copper washers under the nut, which helped, but I still have a leak with just the weight of the bike on them. All of the familiar gremlins are absent: all gaskets (paper) are installed correctly, the oil lock bushings and bottom of both sliders are smooth and free of debris, and the stud protrudes through bottom slotted washers flush. Aside from the leaking, the forks function fine. What's going on here?

I took them to a reputable local shop, and was told to give up because it's possible the sliders are '68-'70 (hard to tell, because they're shaved and chromed), and they "will never work". What changed internally on the slider during those years that would make them incompatible? Should I throw a bead of sealant around the slotted washer, use some thread tape, and just get on with it?

[1951 adam]

I think that if the surfaces are clean, it should not leak. And your sure the gaskets are correct? I just put a little grease on my gaskets, no sealer. Never had any issues. Do you think there's a pinhole , or crack? Porosity ?

[RUBONE]

I took them to a reputable local shop, and was told to give up because it's possible the sliders are '68-'70 (hard to tell, because they're shaved and chromed), and they "will never work". What changed internally on the slider during those years that would make them incompatible? Should I throw a bead of sealant around the slotted washer, use some thread tape, and just get on with it?

Absolutely nothing changed and whoever told you that is seriously misguided. The internals (dampers) remained the same from the introduction to the switch to Showa Built forks in the mid '70s.
The entire lower seal is the gasket under the top hats, which MUST be installed correctly and the damper tube keyed into the lower fork leg slot to seat properly along with the external nut and washer. No special tricks or parts.

[VPH-D]

There is a steel serrated washer pressed into the bottom of the leg that the damper registers in. Is the leak coming around this washer, or thru the damper hole? I once had a fork leg do this.
VPH-D

[Huck]

I very lightly stickied up the paper gaskets with 3 bond. no leaks.

[cheezer60]

Thanks for your responses!

I think that if the surfaces are clean, it should not leak. And your sure the gaskets are correct? I just put a little grease on my gaskets, no sealer. Never had any issues. Do you think there's a pinhole , or crack? Porosity ?

I feel like I've over-analyzed these legs, everything looks to be clean and the gaskets are correct.

Absolutely nothing changed and whoever told you that is seriously misguided. The internals (dampers) remained the same from the introduction to the switch to Showa Built forks in the mid '70s.

Thank you! I'm certain he was just upset I brought shaved legs into his shop haha.

The entire lower seal is the gasket under the top hats, which MUST be installed correctly and the damper tube keyed into the lower fork leg slot to seat properly along with the external nut and washer. No special tricks or parts.

Lower gasket is installed correctly. The dampener stud fits through the slotted washer flush (NOT protruding), and there is very minimal play. Torquing down a copper washer under the stud nut slowed down the leak quite a bit.

There is a steel serrated washer pressed into the bottom of the leg that the damper registers in. Is the leak coming around this washer, or thru the damper hole? I once had a fork leg do this.
VPH-D

The leak is slow, and fork oil is messy. The best I can tell, it's coming from between the dampener stud and the slotted washer.

[Hauula Pan]

I assembled a new aftermarket front end a while back & it leaked like a sieve, I ended up taking it apart & doubling the thin paper seals & put it back together & no more leaks. I found that you can also get some thicker after market fiber seals & they seem to solve the leak issue too. It appears that with just one thin seal the stud is not pulled tight enough against the seal when you tighten the nut, but adding an extra seal or two is all that's needed to allow the stud to be pulled down tight.

[Panacea]

Hauulla pan Suggested the same thing I was thinking, those paper washers are too thin to put any sealing pressure on the damper bushing if the stud part of the bolt is flush with the slider, (if the stud was just a tad shorter, the nut could squeeze the assembly for a good seal). I used some extra paper washers when I did mine on my 51 and had no leaks. Sealers just make a problem for the next guy. I believe this is all documented in the knowledge base...Now that you have oil seeping any sealer would likely be useless...Mike

[drinner-okc]

I've found a 'modern technology' fix for this and other places we used copper washers. Most hardware places carry something they call a 'seal-lock washer' it's rubber bonded to steel. It's rubber one one side, steel on the other and has a built in o-ring to seal around the bolt. The rubber side goes against the tube.