Hi Larry,
I hope it's not this and even hate to mention it, but the other primary cause of extra play in the clutch and running out of adjustment on the pushrod is a sheered off dreaded taper pin at the release fork.
Look at Mark's picture and yours. In your pic, the bottom of the release lever appears a few degrees rearward of vertical. In Mark's, it might be a few degrees forward of vertical. This could just be how it appears in the photos, due to slightly different taking angles or lens distortion, but if it's actually like that it would be another possible indication of a taper pin failure. (I also note that in Mark's pic much less of the pushrod is exposed than in your photo, but that's a symptom and you already know it becasue you are running out of adjusting threads on the pushrod.)
Another possible clue if a new taper pin failed, did the clutch work okay for a while, and then suddenly seem to have a lot of play?
The other folks are right about the elongated holes in the lever or clevis fork. Even the clevis pin itself can wear as well. Also, inside the bellhousing the two pins in the end of the release fork - that slide in the slot around the throwout bearing carrier - can wear on the sides and add noticible play.
If they are all worn to a degree, it can add up to significant play in the clutch.
I know you have been assembling the car recently. Is the taper pin new? Is it the hardened or high tensile steel type? Is it reinforced with a second fastener such as a 1/4" hole and grade 8 bolt through the release fork?
Aside from the above, is the slave cylinder aligned with the lever pretty well? Again trying to compare the photos, it looks a little like your SC might be angled slightly downward in the rear, while Mark's appears to sit pretty level. This also could also be an illusion caused by the camera. If the SC isn't level, the only reasons I can think of would be a bent mounting bracket, perhaps due to a missing support stay (the one that goes forward to one of the sump pan bolts, sort of a rod with a slight dogleg in it... Triumph part #128043 if you have a spares catalog to reference)
At least with that large gaping hole in the bottom of the bellhousing you should be able to inspect the if the clutch release fork is moving on the shaft due to a broken taper pin. You might even be able to remove the pin itself, to see if it's sheered off. If it is, though, to repair it the gearbox will most likely need to come out.
Yes, TR6 owners, that external return spring is used on TR4s. And, it's a good idea to retrofit to TR6, for some added security! It looks like Mark is using a heavy duty version. The one on Larry's car is more normally sized. (The Gunst bearing has another spring and special bracket added inside the bellhousing, that actually does the opposite... it pulls the bearing forward to keep in full time, light contact with the diaphragm arms of the pressure plate.) To add this spring (Triumph part #43929, $1.95 at TRF) to a TR6 you'd need to buy the little anchor plate that fits onto the clevis pin (part #106347, $2.95). The TR4 uses a special clevis pin with it's adjustable pushrod, that can't be directly used on TR6. However, part 106347 will fit onto a standard 1/4" clevis pin, as well. It's also a good idea to get hold of one of those kits that convert your TR6 to an adjustable pushrod at the slave cylinder, too, as seen on both the TR4s above. Both of these retrofits can help solve some of the reliability problems on the later cars.
Larry, I hope it's something simple and easily fixed!
P.S. Regarding the large hole in the bottom of the bellhousing, in some respects it may not cause any problems, might even give some benefits besides an easy way to inspect the release fork and TO bearing.
There is a small drain hole there anyway. However, if driven in the rain or often on wet streets, water spray could get splashed up into the large hole and parts might rust more rapidly or the clutch driven disk might be effected. If there is any oil spewed onto the bellhousing by the engine breather or leaks (not that any TR leaks oil!), it's a long shot but some might find it's way up in there and foul the driven plate. Other than that, the large hole should help keep the clutch nice and cool and gives a good outlet for dust from the driven plate!
Even so, perhaps a fabricated sheet metal cover plate would be a good idea.
The only other concern I would have is weakening the bellhousing, which was beefed up anyway to prevent cracking on later cars. The large hole, and possibly any added to attach a fabricated cover *might* weaken the bellhousing, although they usually break up around the mounting flanges. It's one of those things you just have to wait and see.
Hi Guest!
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