Timo Posted June 1, 2020 Report Share Posted June 1, 2020 Having overhauled the clutch master cylinder due to the typical leak and loss of paint I thought it only wise to service the slave cylinder too. I ordered a slave cylinder service kit for a TR5/6 only to discover that slave cylinder installed was 7/8" and not the expected 1". I then went ahead and ordered a 1" slave cylinder so that it would make the clutch operation lighter (I already have a 0.75" master cylinder). On installing the new slave cylinder I noticed that I did not need to depress the slave cylinder in order insert the clevis pin on the clutch arm. I was expecting that I would have to push the cylinder in some way before aligning the pin with the central hole on the clutch. Is this as expected? Comparing the two cylinders the new 1" cylinder comes up about 1/2" shorter when installed. I've also noticed that the input into the 7/8" cylinder is also smaller diameter than that of the 1" slave cylinder so thought it would be best to get some advice here before ordering a new clutch hose and then finding further issues. Appreciate any suggestions from anyone, thanks Quote Link to post Share on other sites
Timo Posted June 5, 2020 Author Report Share Posted June 5, 2020 Having bled the clutch now, the piston in the slave cylinder almost pops out of the cylinder when depressing the clutch pedal. I've added some spacers between the cylinder and mounting bracket for now but want to work out the cause of this. It looks like the rod is having to travel further back to disengage the clutch the clutch. There is a lot of play in the clutch lever arm about 1 inch of travel at the end of the level. From what I understand the lever should be vertical whereas from the photos you can see when it is pushed rearwards until resistance is met it is not vertical. The clutch was operating fine before servicing master and slave cylinders but does this indicate a problem with something inside the bell housing? The slave cylinder mounting bracket is mounted on the engine side, the slave cylinder is mounted on the bell housing side of the bracket, and the clutch rod is 6" in total length, or 5.75 from tip to centre of the hole for the clevis pin. Quote Link to post Share on other sites
ntc Posted June 5, 2020 Report Share Posted June 5, 2020 The travel when pressing the clutch at the arm should be no more than 16mm if that helps. Quote Link to post Share on other sites
stuart Posted June 6, 2020 Report Share Posted June 6, 2020 Looks as if the actuating lever arm pin has gone as the arm goes back that far before contacting the clutch. Item 17 on here. https://www.moss-europe.co.uk/shop-by-model/triumph/tr5-6/clutch-transmission-drivetrain/clutch-systems/clutch-system-tr5-6-1967-76.html Stuart. Quote Link to post Share on other sites
TonyC Posted June 13, 2020 Report Share Posted June 13, 2020 Sorry if this is a bit late but I recently had a slave cylinder failure (see my post April 10). The replacement slave I obtained (1"bore) specified for the TR5/6 (ex James Paddock) only had one side of the mounting flange machined therefore only allowing one mounting option onto the engine mounting plate - the incorrect one! In both the Haynes manual an Roger Williams restoration book, reference is made to 'ensure that the slave cylinder is installed the correct side of the mounting plate, and also the right way up..... ... fundamentally, the flange on the cylinder should be to the rear (i.e. the differential side) of the bracket. The bleed screw at the top...' The cylinder from James Paddock only allowed mounting to the front, which would not allow correct actuation. I have since obtained another cylinder specified for the Triumph 2.5 and is a 7/8" bore and the mounting flange is machined flat on both sides allowing front or rear installation. I have yet to fit it but visually it looks to be the correct one. Hope it helps. TonyC Quote Link to post Share on other sites
Timo Posted June 14, 2020 Author Report Share Posted June 14, 2020 I test drove the car over the weekend and clutch is operating as before so the hydraulic overhaul has been a success albeit with the additional spacers. I agree Stuart, it’s pointing towards a broken pin! Will the pin completely fail at some stage and the lever arm not operate the fork? I’m assuming part of the pin is still preventing the lever arm from rotating. Thanks Neil, I did measure the travel on the slave cylinder once I had bled the system and it looked like it was in the region of 16mm. I spotted that in one of your earlier posts. Thanks Tony, never too late adding more info into the mix. The replacement slave cylinder I sourced (tvs girling oem) also had the wrong side of the mounting flange machined. That did puzzle me initially but as the non-machined side was fairly flat I went ahead and installed it. I don’t think it is uber critical for the mounting surface to be machined flat, does it? The 7/8 slave cylinder I removed could have been specified for the Triumph 2.5 and installed for the same reason. I decided to go for the 1” bore which in theory should provide a lighter clutch operation than the 7/8. Looks like it's out with the gearbox in the winter! Quote Link to post Share on other sites
Mike C Posted June 14, 2020 Report Share Posted June 14, 2020 Yes- "Will the pin completely fail at some stage and the lever arm not operate the fork?" Quote Link to post Share on other sites
stuart Posted June 15, 2020 Report Share Posted June 15, 2020 12 hours ago, Mike C said: Yes- "Will the pin completely fail at some stage and the lever arm not operate the fork?" TBH they mostly jam part way round on the remnants of the pin as they dont tend to sheer straight across. It then also makes it difficult to dismantle and often the only way is cut the cross bar off to get the remnants out. Stuart. Quote Link to post Share on other sites
elclem1 Posted June 15, 2020 Report Share Posted June 15, 2020 I had a similar problem to this and indeed thought the pin in the cross shaft had sheared. I know it was a new pin and cross shaft as I had fitted them a months before I took the box out and it hadn’t! Luckily I have a few crossshafts from old gearboxes and checked the orientation of the arm on the cross shaft to find there was a difference of about 12mm and the amount of travel needed was too much for the slave piston to move the lever. I changed the cross shaft and behold it worked. New parts are not necessarily exact copies of the originals lesson learned. Quote Link to post Share on other sites
stuart Posted June 15, 2020 Report Share Posted June 15, 2020 18 minutes ago, elclem1 said: I had a similar problem to this and indeed thought the pin in the cross shaft had sheared. I know it was a new pin and cross shaft as I had fitted them a months before I took the box out and it hadn’t! Luckily I have a few crossshafts from old gearboxes and checked the orientation of the arm on the cross shaft to find there was a difference of about 12mm and the amount of travel needed was too much for the slave piston to move the lever. I changed the cross shaft and behold it worked. New parts are not necessarily exact copies of the originals lesson learned. Where did the incorrect cross shaft come from? Stuart. Quote Link to post Share on other sites
elclem1 Posted June 15, 2020 Report Share Posted June 15, 2020 Tr shop I think. Quote Link to post Share on other sites
stuart Posted June 16, 2020 Report Share Posted June 16, 2020 14 hours ago, elclem1 said: Tr shop I think. Interesting as I have had new ones from there no problem, they would have ultimately come from Moss I think anyway. Stuart. Quote Link to post Share on other sites
astontr6 Posted June 16, 2020 Report Share Posted June 16, 2020 21 hours ago, stuart said: TBH they mostly jam part way round on the remnants of the pin as they dont tend to sheer straight across. It then also makes it difficult to dismantle and often the only way is cut the cross bar off to get the remnants out. Stuart. ORS always put another pin in when they re-con a gear box to guard against this problem, I had this problem in the early 80's and used an Unbrako socket cap. You will not sear that?? Bruce. Quote Link to post Share on other sites
elclem1 Posted June 16, 2020 Report Share Posted June 16, 2020 Stuart, yes from moss or the supplier to moss, I check all of the others I have here and they are all in the same orientation as the one I finally fitted. Maybe a rogue one? It’s one thing I will check before fitting next time. For sure! Quote Link to post Share on other sites
stuart Posted June 16, 2020 Report Share Posted June 16, 2020 3 hours ago, astontr6 said: ORS always put another pin in when they re-con a gear box to guard against this problem, I had this problem in the early 80's and used an Unbrako socket cap. You will not sear that?? Bruce. Yes I know that, thats what we do every time as well. Stuart. Quote Link to post Share on other sites
elclem1 Posted June 16, 2020 Report Share Posted June 16, 2020 Unbrako socket cap? Quote Link to post Share on other sites
Mike C Posted June 17, 2020 Report Share Posted June 17, 2020 By far the highest tensile strength fastener available to the masses: https://www.unbrako.com.au/socket-screws#tab-2 Quote Link to post Share on other sites
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