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TR2/3/3A Mounting Slave Cylinder

frankfast

Jedi Trainee
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According to the illustration in the shop manual the slave cylinder bracket is mounted behind the flange on the transmission and the slave cylinder is mounted on the back of the bracket. My cylinder is currently mounted in front of the bracket and am having problems with the pedal as if there is air in the system. I have to pump the pedal once or twice to get the pedal where it should be.I'm sure that there is no air in the system. I've adjusted the rod multiple times but am almost out of adjustment. Should I move the the cylinder to the back of the bracket as the manual shows? Per the manual there should be almost no play at the forked end of the rod.
 
The shop manual for TR3 shows a Lockheed clutch. Is that what you have?

This is the correct Girling setup, with the slave mounted on the front of the bracket
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From your description, though, I would guess that you're suffering from the dread broken taper pin. One of the symptoms of a broken pin is that there is not enough range of adjustment to get the correct 0.1" freeplay at the slave cylinder pushrod.

PVOjiNH.jpg
 
I have the Girling system so the cylinder is mounted correctly. Do you have an illustration showing this tapered pin? I don't know what it looks like. Thanks.
 
If the piece was broken and both halves fell out of the shaft the clutch wouldn't disengage at all because the shaft would turn inside the fork. Right? If the broken half was still stuck in the shaft it would still work. Why when I pump the pedal does the clutch work fine?
 
The reason the pin breaks is because the hole in the fork is too big. The pin is safety-wired and the threaded part blocks the hole, so there is no way for the broken end to fall out. So it stays in the hole and eventually the the fork twists far enough that the pin jams in the oversize hole. It's not a lot of lost motion (maybe 15 or 20 degrees of rotation), but it's enough to take it beyond the normal range of adjustment.

With the freeplay too large, the return spring pulls the pushrod back against the slave piston, and bottoms it in the bore. (This is normal operation for TR2-TR4.) Pumping up the pedal takes up the excess freeplay, giving you a clutch that works until you release the pedal. Releasing the pedal opens the return valve in the MC, which allows the return spring to pull the piston back and puts you back into the situation where there is too much travel required for one stroke to provide.

I actually got mine to work briefly, by making up a longer pushrod (that could be adjusted with the broken pin). But it fairly quickly damaged the pin and fork enough that I could no longer adjust it.

Getting that broken end out is actually something of a trick; it probably wouldn't fall out even if the threaded part did. The Buckeye article shows essentially the same thing I did: drill a hole through the fork right above the pin, then get the fork and shaft aligned "just so" while tapping the pin out with a punch and hammer.

FWIW, I used an additional bolt to reinforce that joint. 1/4 NF Grade 8, with the hole drilled undersize so the bolt is a light drive fit into the hole. The article presents several other ways to reinforce it. But you still need a new pin to get the alignment between fork and shaft just right.
 
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Thanks for the explanation. I now understand what is happening. Until the tranny is removed, I guess I'll continue to double clutch. It seems clear that the pin is broken.
 
I've decided to remove the transmission and repair the broken pin (believing that is the problem). i've never done this job before so am interested in any helpful techniques since I'm going mainly solo. Everything has been removed from the the transmission and am ready to remove the bolts from the bell housing. First I'd like to support it from a dolly below so i'm able to shift it a little and then with some help from my daughter we may be able to lift it out of the car by swinging it out the passenger side door. I have no idea how heavy it is. Am I dreaming? Any helpful hints out there.
 
Make sure you also support the back of the engine. It's best if you get it up as high as possible, so the transmission can come straight back but above the tunnel. It has to come out absolutely straight until the splines are free from the clutch plate, 3 or 4 inches; then you still can't turn it very far until the tip of the shaft is out of the clutch plate. You'll also have to roll it slightly to the right, so the clutch lever will clear the floorboards.

It's not too bad, maybe 60-70 pounds without overdrive. I've done it without help.
 
There was a photo of a tool to help support the transmission on here a few days ago. It bolted to the firewall and had an arm that extended back into the passenger/driver area. I will see if I can find it in the morning.

David
 
Are you saying raise the transmission by jacking via the engine sump pan? Do the bolts in the bell housing come out before it is raised?
 
Put the jack under the bell housing to jack the engine and gearbox as one then support the engine with a large block of wood under the sump with another support under the gearbox. Make sure the gearbox support is not weight bearing so when you take the bell housing bolts out the box can slide back and out of the clutch.
To make the job easy make up my gearbox removal leaver as posted last week, it's simple and takes the hard work out of it. The first photo is on its side and the second one is upside down and i dont know how to fix it can any one help

Graham
IMG_1628.jpg
IMG_1631.jpg
 
If you're a PC user, IrfanView is a free program that performs lots of simple imaging editing tasks. 90 degree rotation is as easy as tapping 'L' or 'R' once, 180 is twice. It can also rotate by mere fractions of a degree (handy when a page didn't align quite right in the scanner). https://www.irfanview.com/

GTKCPgt.jpg


Rlcr1Sn.jpg
 
Are you saying raise the transmission by jacking via the engine sump pan? Do the bolts in the bell housing come out before it is raised?
You can take out some of the bolts before; but you want to leave the gearbox bolted to the engine until the moment when you're ready to pull it all the way off. You don't want to let the input shaft take the weight of the gearbox.

I assume you've got the TR3 workshop manual, but the TR4 manual makes the process a bit clearer
be0BGHZ.jpg
 
I managed to remove the gearbox solo. It was easier than I thought. Unfortunately when I removed the pin, I found it intact. It was not broken. Back to the drawing board. I now suspect a faulty slave cylinder although it was new from Moss. I used silicone brake fluid which worked fine for the brakes. I could try another slave from Roadster Factory but at this point I'm shooting in the dark.
 
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Sorry to hear you didn't find the problem. Did you at least figure out why you couldn't get it adjusted properly?

The fill plug is right in the center of your photo, that square headed pipe plug is the fill on the later gearboxes.

Sounds like you might need a copy of Practical Hints, which is effectively the factory owner's manual. Here's a PDF of the 6th edition, suitable for later TR3A and TR3B
https://drive.google.com/open?id=0B2H2NJt34OffNjQ4MTkyNjItZTVmYi00M2U2LWJhYWUtMjEyZDgxMzUyNzUw
 
Did you mean adjusting the slave cylinder rod to gearbox lever. I was never able to adjust it properly. The last time I tried the rod ran out of adjustment. It wasn't long enough.
 
Now I'm really confused. The shop manual calls for SAE 30W in the gearbox whereas the Practical Hints is calling for 90W. Which is it?
 
Yes, you mentioned before running out of adjustment, which is a prime symptom that something is wrong. The adjustment is important (for the reasons I already explained), although the exact number isn't all that critical.

Triumph changed their recommendation on transmission oil between the time the shop manual was written and that edition of Practical Hints. Ken Gillanders (an ex-dealer mechanic and owner of British Frame and Engine) looked into the reasons some years back, and got the answer that the factory had been experiencing a high failure rate of countershaft bearings (or maybe it was thrust washers). They felt that using "hypoid" oil (ie GL4 gear oil) would help save the bearings.

They must've felt it worked, as they continued specifying GL4 through the end of TR6 production.

(There was actually an earlier service note, that said they "allowed" use of GL4, if overdrive was not fitted.)
 
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