In the process of doing the top end the DnD Fatcat exhaust was off so I decided to fix an oil leak at the cable to clutch cover interface as it had a real slow leak and I figured to go through and fix all the leaks I could identify. When I'd changed the clutch cable about 65000 miles ago, I tried to seal it with high temp silicone but it eventually started leaking. It was time to fix it right..
Here is a pic of the tranny cover where the O ring seats..
Now I understand why HD want's you to use pipe dope on everything. It's obviously a pretty crappy seat for an O ring..
So the next step was to get the hole pointing up and cut the seats.. I used a valve guide setting tool that gets the hole perpendicular to the table. It's basically a level that references a V groove with a clamp.. The fixture plate is something I made for another project.
After cutting the O ring seat, I cut the seat for the cable nut to something less then 3/32 above the O ring seat as the standard O ring is for a 3/32 grove.
Here is a pic of the done seats.. Hopefully it won't leak..
I think that the actual sealing surface is the bevel. Not the face. O-rings are not flat face sealing where you would normally use a flat gasket. Problem is, Harleys shake and you do not want to depend on that flat gasket keeping the application tight. You want a torque metal to metal face and the o-ring either in a groove or a much cheaper application using a tool called an MS seal cutter (It also has a military spec beginning in J and the SAE.
There are at least 16 sizes in the series. It produces the tap drill size for the threads, a bevel for the o-ring to go into, a washer face for metal to a metal torque of the bolt or in this case the clutch cable end and also another face of the cutter is also used if the part being cut is a casting on rounded face.
We used them all the time where I worked on Submarine and Air Craft carrier new work. Never ever used the big ones in the following shortcut. We would produce it on are NC equipment. However, the smaller ones only required a spot drill, a pilot drill, the MS cutter and then a tap to produce a very complicated part.
Harley also uses this for the three plugs in the transmission, primary and oil bag.
As cut, now that you have removed some of the bevel, the o-ring is going to lay over on the face since it cannot go completely into the bevel. However, the application is next to no pressure since the transmission is opened to the outside with the vent tube.
I have seen numerous leaks here that come from oil getting on the cable when the filter is changed. Most OEM cables have an extra protective hose around them that was slid on. Oil gets in this and blows back in time to the transmission.
Last edited by Jackie Paper; 09-14-2018 at 07:47 AM.
I think that the actual sealing surface is the bevel. Not the face. O-rings are not flat face sealing where you would normally use a flat gasket. Problem is, Harleys shake and you do not want to depend on that flat gasket keeping the application tight. You want a torque metal to metal face and the o-ring either in a groove or a much cheaper application using a tool called an MS seal cutter (It also has a military spec beginning in J and the SAE.
There are at least 16 sizes in the series. It produces the tap drill size for the threads, a bevel for the o-ring to go into, a washer face for metal to a metal torque of the bolt or in this case the clutch cable end and also another face of the cutter is also used if the part being cut is a casting on rounded face.
We used them all the time where I worked on Submarine and Air Craft carrier new work. Never ever used the big ones in the following shortcut. We would produce it on are NC equipment. However, the smaller ones only required a spot drill, a pilot drill, the MS cutter and then a tap to produce a very complicated part.
Harley also uses this for the three plugs in the transmission, primary and oil bag.
As cut, now that you have removed some of the bevel, the o-ring is going to lay over on the face since it cannot go completely into the bevel. However, the application is next to no pressure since the transmission is opened to the outside with the vent tube.
I have seen numerous leaks here that come from oil getting on the cable when the filter is changed. Most OEM cables have an extra protective hose around them that was slid on. Oil gets in this and blows back in time to the transmission.
There isn't any bevel on this.. Never was.. Only flat surfaces were cut. (Actually they weren't flat to start, chrome pitted)
The O ring used is a std -109 with 5/16 ID and they rely on a flat compression surface..
Look at the end of the cable.. It too is flat and there isn't any undercut for the O ring to drop into..
The difference between the 2 steps was cut to 0.090 which is a little tighter than spec (3/32) but there is still enough volume for the O ring to move into as it crushes. You can look each internal corner and see the chrome was still there. If you have any questions about cutting these syrfaces, please ask.
You are correct about some cables leaking due to the sleeve picking up oil from a change. They can also leak at the joint. I believe you are are correct about the drain plugs using a bit if a taper to seal.. It's one of the reasons why you use a -013 o ring instead of a -014 on the 1/2 -20 drain plug bolt. -013 is std 7/16 id.. With the cable junction only being 5/16-24 there really isn't any room for an undercut and a -109 O ring has a 5/16 speced ID.
For instance these tranny filler caps are undercut fit the undersized O rings..
The tranny plug is a 3/4 thread but the O ring ID is 11/16 (-115) Stock HD tranny dipsticks are typically not made right, the undercut is too small and crushes the O ring BTW. HD only wants it TQed to 25-75 inch-lbs to save the O ring..
06-23-2017, 07:54 PM
Fixing the cable oil leak at the right side tranny cover.
