Once a Prototype always a Prototype

I shall call it a P12S. ha

I usually prototype my ideas and if they work, leave them without making them show quality. Below are some scary views of my Frankenstein special. These shots were taken before I started taking the primary apart to get at the TTi 5-speed leaking seal behind the drive sprocket. Really not going to be that much fun to replace the seal. Need a magic hook to get the seal out unless I tear out the gearbox guts, which I really don't want to do yet.

Is it a situation where you can get self-tapping screws into the seal, to pull it out with?

Self tappers do work, if the seal has a metal surround then drill a small pilot hole first, drill size equal to or preferably smaller than the root diameter of the self tapper.

Triton Thrasher said:

Is it a situation where you can get self-tapping screws into the seal, to pull it out with?

Click to expand...

kommando said:

Self tappers do work, if the seal has a metal surround then drill a small pilot hole first, drill size equal to or preferably smaller than the root diameter of the self tapper.

Click to expand...

Thanks for the thoughts. The strongest small 90 degree hook I have worked.

I don't know how many people have worked on a TTi 5-speed gearbox with a Manx mainshaft, but I'm kind of surprised they don't all leak a little given where the lip is on the seal and the use of a spacer over the sleeve gear. The spacer barely rides inside the seal and the spacer ID isn't sealed. It could have been leaking through the ID of the spacer. It wasn't a terrible leak, but it was a leak. So if it dribbles a little after installing the new seal, I'm not going to worry about it. By the way, I turned the spacer around so the seal would ride on a new surface not the old worn smooth one.

Nobody needs to ensure me that is impossible, since a leak where I had a leak is also supposed to be impossible.

Out with the old.


In with the new


I did not replace the little seal on the mainshaft. I may end up regretting that, but there was no evidence of a leak on the back of the clutch basket or around the mainshaft. Besides it's not all that messy or difficult to take the primary off with a dry clutch.

By the way, I drove that new seal in with a 1 1/2-inch PVC coupler I had for schedule 40 PVC pipe. Just the right length, OD, and ID with the spacer in place to get the job done.

Carry on

If the sleeve turns with the sleeve gear, can’t you put the sleeve on with sealant?

Triton Thrasher said:

If the sleeve turns with the sleeve gear, can’t you put the sleeve on with sealant?

Click to expand...

Interesting idea. TTi doesn't use any goop inside the spacer. The spacer is a slip fit on the sleeve gear. The spacer butts up against the inner race on the sleeve gear bearing inside fastened in place by the torque on the sprocket, and it turns with the sprocket and inner race on the bearing inside the case. I'm guessing it shouldn't leak through the inner race face against the spacer, but who knows where oil can get to when it gets hot. I'm underthinking it more than likely.

I'll be test riding it later today to see if it leaks, unless it rains. No more wet weather riding in the remainder of my lifetime.

Here are the sophisticated tools I used for removal and replacement of the seal: lol

The top side shown on the coupler is for driving the seal in without the spacer. It fits over the sleeve gear if used that way. I ended up not doing that, and used the other open end with the spacer in place.

Short test ride did not produce any weeping of gearbox oil at the seal. A longer test ride is required to be sure it's not going to leak like it was. I don't think it will. The new seal is a little stiffer and a tighter fit around the spacer.

I forgot to add the hammer in the sophisticated tools image in post #6.

Triton Thrasher said:

If the sleeve turns with the sleeve gear, can’t you put the sleeve on with sealant?

Click to expand...

I've done it for 50 years on every sleeve on every motorcycle transmission.
The question is why WOULDN'T you?

concours said:

I've done it for 50 years on every sleeve on every motorcycle transmission.
The question is why WOULDN'T you?

Click to expand...

The old I've done it for 50 years card. lol

I went for a 10 mile mildly frisky loop ride and got the gearbox up to 95 degrees about an hour ago. Not a drop of gearbox oil got past the spacer or seal when I got back, and it use to leak after that same short loop every time over the last 2 years. What if I knew what I was doing? Stranger things.

TTi does not use a sealant on the spacer ID or OD, and TTi has only been making Norton gearboxes since 2003. According to my math is a bit less than 50 years. The gearbox was leaking at the seal on the outer diameter of the spacer not past the ID of the spacer like I thought it might. Wrong assumption on my part.

I WOULDN't use sealant because I wouldn't given how the gearbox was assembled.

You did put oil in, yes ?
The drip from the gear indicator is p*ss*ng me off at the moment..
I've tried 'O' rings of all sizes, 'X' rings too, beginning to think the only definitive way is to shorten the inner shaft and weld shut the outer..

EstuaryBoy said:

You did put oil in, yes ?
The drip from the gear indicator is p*ss*ng me off at the moment..
I've tried 'O' rings of all sizes, 'X' rings too, beginning to think the only definitive way is to shorten the inner shaft and weld shut the outer..

Click to expand...

I replaced all the parts associated with that shifter including the bushing. Also tried o-rings, x-rings, custom cut rubber behind the indicator. Nope. I had other problems with the gearbox off and on for decades, and the little 3 spring AMC clutch wouldn't hold on hard acceleration with the lighter rotating mass and FCRs. It worked well when the engine was closer to stock though.

A 5-speed is really nice on winding roads. Much better than a 4 speed for me. Much easier to keep the engine in the meat of the cam power band. Too bad they are pricey. A TTi 5 or 6 speed would be a serious improvement on a Commando in the tight stuff. I'll never know though. The Norton Koolaid wore off a long time ago for me. lol

I did not have to drain the gear oil to replace that seal. There is a smaller seal on the end of the sleeve gear that keeps the oil above the bottom of the mainshaft in the gearbox. I use a Mercruiser synthetic gear oil. Good stuff in the TTi gearbox and cheaper than the usual suspects like Royal Purple, Motul, BelRay and so on. Standard hypoid gear oil was terrible in the TTi gearbox. 90 wt Hypoid made finding neutral, which is fiddly enough with better oil, really a pain in the arse. The Mercruiser gear oil might have been an improvement in the P11 AMC gearbox, but I never tried it.

Schwany said:

The old I've done it for 50 years card. lol

I went for a 10 mile mildly frisky loop ride and got the gearbox up to 95 degrees about an hour ago. Not a drop of gearbox oil got past the spacer or seal when I got back, and it use to leak after that same short loop every time over the last 2 years. What if I knew what I was doing? Stranger things.

TTi does not use a sealant on the spacer ID or OD, and TTi has only been making Norton gearboxes since 2003. According to my math is a bit less than 50 years. The gearbox was leaking at the seal on the outer diameter of the spacer not past the ID of the spacer like I thought it might. Wrong assumption on my part.

I WOULDN't use sealant because I wouldn't given how the gearbox was assembled.

Click to expand...

I had quoted and was responding to TT's post. (Please refer to my post).
I was not attempting to tell you anything.
You're doing a great job, carry on.

concours said:

I had quoted and was responding to TT's post. (Please refer to my post).
I was not attempting to tell you anything.
You're doing a great job, carry on.

Click to expand...

I was butting in and telling you why I didn't go that route. I noticed you were responding to TT, but I figured it was a universal technique used by many. I've never done it, but that doesn't mean a lot. Also trying to shepherd my post. Don't want to ignore anybody participating with positive input.