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The dreaded broken clutch fork pin!

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Banjo

Banjo

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I have the TR4A tranny I'm going to use on my TR2 at work, and have been tinkering on it when I have the odd few minutes here and there. So far, I've opened it all up, inspected the internals, made a list of parts (thankfully just gaskets and seals) and cleaned it all up.
Today I decided to take the clutch rod and fork out to inspect all that stuff. Guess what I found? The classic TR clutch problem. The head of the fork pin came out, leaving the rest of the long-ago broken pin jammed up in the rod, and keeping the fork loosly stuck on the rod. Biggest thing is, you can't get a straight shot on the hole where the pin is.
Tomorrow I'm gonna inspect the rod closely for wear. If it needs replacement, it's gonna get hacked off! if not, I'm thinking of drilling a small hole in the fork from the top, and seeing if I can tap the pin out that way. Or drilling a hole in the bottom of the bell housing so I can get at the pin that way (But I think I'd rather replace the rod first).
I'll definatly be adding an extra bolt or pin on re-assembly Like Roger Williams suggests in his book.
Just thought I'd share the fun. hehehehe
 
Yep, btdt several times. Drilling a hole from above and driving it out worked great once for me, another time I just couldn't get it to budge and cut the thing out. Definitely agree that an extra grade 8 bolt helps, at least I think it does!
 
Couldn't tell driving but mine was broken when I took it apart. The drill and punch worked well. I put an extra 1/4" pin in the new one. Have fun.
 
I've been lucky (so far) with drilling from above. Mentally extend a line through the center of the pin, and use a punch & BFH to put a punch mark where the line hits the surface of the fork. Then start the hole in that punch mark, at right angles to the surface. Once you've got the hole started, gradually turn the drill until you're drilling towards the pin.

Still using the fork that I treated that way, maybe 10 years ago now.

Haven't seen the Williams book, but I definitely added a bolt to mine. One tip, be sure you have the fork turned the right way on the shaft before drilling the hole :laugh: Also make sure you trim the bolt so it can't catch on the front cover.
 
Randall, Nice job on the bolt. that's pretty much what I was looking at doing.Did you replace the pins on the ends of the fork that ride in the groove of the throwout bearing before installing that? the ones in the picture are rather worn out ($1.80 each through Moss). 'Course being behind the 4 cyl engine that's probably ok. May have been an issue on a TR6. Those clutches have no tolerance for any worn parts.

I may wind up just cutting the shaft, a new one is under $30, and it has the provisions for grease fittings that mine does not have.
Or I may try the drilling trick, and try to save the shaft.....just in case.
 
Sorry for any confusion; that photo is from Nelson Riedel, not me. You may have noticed, there is no hole for removing the broken taper pin, either. The entire article should be available on the Buckeye Triumphs site.

In my case, I did replace the shaft as the ends were rather worn and it was chewed up in the middle from the broken taper pin.

But ISTR I didn't replace the pins that press against the carrier though, as IMO wear in that area tends not to be a problem. With the TR6 setup, the spring inside the clutch slave takes up any slack caused by wear in those pins; while with the TR3 setup it just becomes part of the freeplay adjustment. (Although I'm running a TR6 clutch, I kept the TR3 clutch adjustment.)

Not too hard to drill & tap for the grease zerks; there is more information on the Buckeye site (courtesy Nelson). But on the Stag there is no room for the zerks on the ends of the shaft; so I drilled and tapped the transmission housing instead. Worked out slick, I'll probably do it that way on the TR if I ever revisit that area.

DSCF0054.jpg


I also converted to the wide brass bushings used on the slave cylinder side of the TR3, rather than the narrower steel bushings that were original to the Stag (and TR6). Hopefully next time, only the bushings will need replacing instead of bushings plus shaft.
 
Hi Ben,

I had no luck removing the stub of the broken pin and buggered
up the fork and the shaft in the process. I bought a new TR4A
shaft and fork and double bushings for my TR6. Worked great so far in my TR4A tranny.

Dale



clutchbarmods.jpg
 
Drilling the little hole from the top worked like a charm on my pin. guess I got lucky this time. No noticable wear on the shaft, and the fork looks ok as well, so I'll probably just replace the bushings in the bell housing (Using the wider ones of course) and drill the trans for the fittings like in Randalls' pic. Also install the bolt like both Randall and Tinster have shown.
Love the paint job on that bolt Dale!
 
No doubt what grade that bolt is. Nice example to show of how it's done too.
 
Brosky said:
No doubt what grade that bolt is. Nice example to show of how it's done too.
Click to expand...

<span style="color: #660000">Sadly, I not yet attained powder
coating skills or it would have looked more professional.</span>
 
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