Installing the clutch release bearing/sleeve to gearbox

[foster461]

Is it possible to attach the clutch release bearing assembly to the gearbox with the fork attached to the shaft or does the fork have to be un-pinned from the shaft to allow the whole thing to be assembled and the fork pinned to the shaft at the end ?

 

I dont seem to have enough wiggle room to get the thing assembled with the fork attached although I could swear I got it off two years ago without removing the pin from the fork...

 

Stan

[BlueTR3A-5EKT]

No special trick. The fork does not need unpinning in my experience.

The carrier assy usually falls off when you are putting the gearbox back in the car.....

To stop this tie the clutch lever to the bell housing with a length of wire.

 

 

Peter W

[peejay4A]

I just needed to jiggle the assembly a little bit to get it to slide back on the nose piece. No unpinning needed, which would have been a pain as it's roll pinned.

[foster461]

What I'm finding is that to get the fork to rotate enough for me to get the sleeve/bearing onto the nose of the gearbox I have to slide the shaft out a little to allow the head of the fork pin to clear the bolt securing the idle shaft plate. Once I have the sleeve engaged with the fork and maneuver things back into position once again the fork pin is again hitting that bolt. Maybe this pin has more material on it than it should. I cant see this working unless the pin comes out or maybe I can get the cover plate bolt out and back in once the fork and bearing are in place.

 

I'll have another go at it later today.

 

Stan

[peejay4A]

I've just had a look a a photo of mine that I took and I see what you mean. My taper pin head fits quite close to the fork when fully tightened and wired. Maybe yours is a bit proud.

[foster461]

ok, the plot thickens.

 

I removed the RH bolt from the cover plate to allow the fork to move freely. Now I can see the real reason why the fork wont engage with the sleeve and it is nothing to do with the bolt. I had pressed the sleeve into the new release bearing so that the flange on the sleeve was up against the rear of the bearing. With the sleeve in that position there is insufficient room for the ends of the fork so the pins on the fork cant engage with the slot in the sleeve. If I back the sleeve out of the bearing by maybe .25 inches then the assembly goes together with no fuss.

 

Now the question is do I have an odd fork or is this normal and you cant push the sleeve all the way home. Time for a bit more research.

 

Stan

[Graham Harris]

Stan, when you get it sorted make sure you reseal the Lay shaft cover. You would not believe how much oil can leak out that little cover plate.

Graham

[foster461]

Stan, when you get it sorted make sure you reseal the Lay shaft cover. You would not believe how much oil can leak out that little cover plate.

Graham

 

Good point Graham.

 

Here's where I am with the release bearing.. With the sleeve inserted into the bearing but not pushed fully home, the sleeve can just be eased onto the fork and the fork pins engaged into the slot on the sleeve. The trick seems to be to make sure the sleeve is square to the bearing so it can slide up and down the nose. I imagine that in operation the sleeve will find its own position in the bearing as long as it is not totally seized and perhaps even end up with the flange on the sleeve up against the back of the bearing. I'll pull it off and get a picture later.

 

Stan

[foster461]

Here's a picture of my release bearing and sleeve. The sleeve is inserted into the bearing as far as possible while still allowing the fork to engage. You can see that the flange on the sleeve is about 3/16 inch from the rear of the bearing and I'm speculating that in operation this gap will close as the sleeve gets pushed further into the bearing over time. If the sleeve is pressed in beyond the point shown, the ends of the fork will hit the bearing before the pins get a change to engage in the slot in the sleeve.

 

[Graham Harris]

Stan, have you had the fork locating bolt out and or the fork off the shaft, the reason i ask is that the tapered locating bolt should screw right up to the casting of the fork. If it doesn't there may be a piece of broken tapered bolt lodged in the fork stoping it from screwing right in or it's the wrong bolt. I think you will find the bearing should be pressed on up to the flange on the carrier so there is no movement after assembly to upset cluch adjustment.

Graham

[stuart]

Stan can you put up a side on picture of the fork engaged on the sleeve.

Stuart.

[foster461]

Stan can you put up a side on picture of the fork engaged on the sleeve.

Stuart.

 

 

Here's a couple of shots, one from the side and one from underneath. These are taken with the release bearing pushed all the way forward and in the position it would be in at the point where it is being installed and engaged with the two pins on the fork. You can see that in this position the ends of the fork are in contact with the rear of the bearing. If the sleeve was any further forward you cant get the pins into the slot on the sleeve. It looks a bit odd at this extreme forward position but as the bearing moves back to its normal operating range the geometry changes.

 

 

 

 

 

[BlueTR3A-5EKT]

Looks like the front face of your fork fingers could need a bit machined off. That fork would be ok in a diaphragm clutch setup.

I'd take the grinder to it if it were Mine to get the front clearance you need.

 

Cheers

Peter W

[foster461]

Looks like the front face of your fork fingers could need a bit machined off. That fork would be ok in a diaphragm clutch setup.

I'd take the grinder to it if it were Mine to get the front clearance you need.

 

Cheers

Peter W

 

I think we might be getting somewhere Peter and probably where Stuart was heading also.

 

Here is my fork on the left next to a fork from a spare TR4 gearbox on the right. The fork on the right has been machined to a much greater degree than the one on the left (a new fork that came with a new shaft). I think a few mins with the bench grinder should sort this out.

 

 

[stuart]

Thats exactly what I was trying to establish Stan. That casting on the new one does look very badly made. Where did it come from? I would be inclined to inform the suppliers of the problem to save anyone else the same grief.

Stuart.

[foster461]

Thats exactly what I was trying to establish Stan. That casting on the new one does look very badly made. Where did it come from? I would be inclined to inform the suppliers of the problem to save anyone else the same grief.

Stuart.

 

Not sure where the shaft and fork came from, will have to dig back through the paperwork from two years ago.

 

I did modify the new fork to give it a better profile and now the sleeve is fully home in the bearing and the sleeve installs on the fork with no drama. The new fork doesnt look bad, a bit beefier than the original, apparently too beefy at the ends of the fork.

 

Thanks everyone for helping me solve this mystery.

 

Stan

[Guest ntc]

That casting on the new one does look very badly made. Where did it come from?

Stuart.

 

It looks awful Good luck Stan

[Kiwifrog]

I have to agree with Neil, that looks like a very rough casting. Does the securing pin fit with no play or did you have to lap it in ?

 

Cheers

 

Alan

[foster461]

I have to agree with Neil, that looks like a very rough casting. Does the securing pin fit with no play or did you have to lap it in ?

 

Cheers

 

Alan

 

Other than the poorly machined ends the fork looks otherwise fit for purpose. Perhaps the extreme close up and the fact that it is new is exaggerating the rough casting. However, sufficient doubt has been expressed about its viability and I will clean up an original fork and use that instead.

 

Stan

[AlanT]

Probably a product of one of the numerous foundries in India. Youtube has some videos of these places.

The way they work has some "interesting" aspects.

 

They tend to make things a bit on the big side. Typically the castings have internal inclusions

 

This has most likely been made with many items all joined and then cut up and machined.

This is why the side view looks different.

[stuart]

 

Other than the poorly machined ends the fork looks otherwise fit for purpose. Perhaps the extreme close up and the fact that it is new is exaggerating the rough casting. However, sufficient doubt has been expressed about its viability and I will clean up an original fork and use that instead.

 

Stan

Dont forget the extra roll pin cross drilled..

Stuart.

[foster461]

Dont forget the extra roll pin cross drilled..

Stuart.

 

This is a roll pin through the center of the fork and through the shaft, essentially pin the fork to the shaft ?

[Guest ntc]

As before Stan

[AlanT]

You will have an amusing task to drill a new fork to match an existing hole in the shaft.

 

Normally you drill through the fork and shaft in one go. But picking up an existing hole in a shaft and making the fork match will want a special method.

[foster461]

Got it, thanks for the picture Neil. Alan, there is no hole in the shaft, the shaft is new and I dont think pinning the fork to the shaft was done at the factory anyway. I'll mount the fork on the shaft with the regular attachment pin and then drill for the roll pin on the drill press.

 

Stan