RogerH Posted October 8, 2020 Report Share Posted October 8, 2020 Hi Folks, not sure if I have posted this before. This is my clutch fork taper removed from the 4A. No cross pin fitted. It had done apprx 40,000 - 50,000miles since fitting (May '16). Apparently this was a good quality pin !!! The crack is the wiggly black line in the middle of the shank. Roger Quote Link to post Share on other sites
cvtrian Posted October 8, 2020 Report Share Posted October 8, 2020 NDT at its best. You need a new one! Quote Link to post Share on other sites
Lebro Posted October 8, 2020 Report Share Posted October 8, 2020 What tool are holding the pin in ? Bob. Quote Link to post Share on other sites
Ian Vincent Posted October 8, 2020 Report Share Posted October 8, 2020 Did you have any other locating method apart from the pin? Rgds Ian Quote Link to post Share on other sites
RogerH Posted October 8, 2020 Author Report Share Posted October 8, 2020 Hi Ian, I don;t need a locating method for the pin - I know where the garage is !!! Hi Bob, That is an oddly shaped horse shoe magnet. The arms are hinged so they contact the item. Roger Quote Link to post Share on other sites
Z320 Posted October 8, 2020 Report Share Posted October 8, 2020 Roger, don't you go fancy with a hydraulic unit? Marco Quote Link to post Share on other sites
iain Posted October 8, 2020 Report Share Posted October 8, 2020 Go on name and shame the source of this good quality item! I am bored of the rubbish we get sold. Quote Link to post Share on other sites
RogerH Posted October 8, 2020 Author Report Share Posted October 8, 2020 Hi Marco, I bought a Saab 9.3 Hydraulic co-axial clutch the other week to try and understand what is going on. It may not fit but they are not expensive. Hi Iain the problem is not the quality of the pins but the special design of the shaft/fork/pin arrangement. 'IF' the mechanism truly did work in a shear force situation then the pin would never fail. Even a HB pencil would work - perhaps not. However the smallest amount of tensile or torsional load will start the rot from day 1. I get my pins from either Moss or the TRShop but I would not complain about their service. It is the design. My TR4 has had the fork modified so that the pin is in double shear so this (and its better fit) will eliminate failure (probably - I haven't done many miles with it) Marco's co-axial slave is the answer. There are proprietary ready to run units on the market but the fun is to make your own. Marco did a lot of measuring and fitting and ended up with a beauty. I would like to go for it my way. Sadly I haven't a map and not sure where I'm going. In the mean time - fit a roll pin at 90 degrees Roger Quote Link to post Share on other sites
Ian Vincent Posted October 8, 2020 Report Share Posted October 8, 2020 Roger, You have answered my question, you have a modified fork so that it is double shear. I have two roll pins as well as the taper pin in mine. The simple fact is that the load will follow the stiffest path so any play in any secondary fixing will mean it doesn't see any appreciable load until the primary fixing has failed. Rgds Ian Quote Link to post Share on other sites
RogerH Posted October 8, 2020 Author Report Share Posted October 8, 2020 Hi Ian, indeed the tightest fit will take the load. Given time that fit will relax slightly and hopefully more than one pin share the load. With the OEM design if (and it is a big if) the taper fit was absolutely spot on then the pin would be up for it. But as we know repro fits and tolerances are not what Armstrong or Whitworth would have wanted. Roger Quote Link to post Share on other sites
BlueTR3A-5EKT Posted October 8, 2020 Report Share Posted October 8, 2020 Roger 1. What will you do when the magnaflux dye runs out? 2. Why did you choose the Saab 93 concentric slave cyl unit? Peter W Quote Link to post Share on other sites
RogerH Posted October 8, 2020 Author Report Share Posted October 8, 2020 Hi Peter, Before I left the worlds #1 airline I did a stock take. I don;t think I will run out unless I do a full NDT of the RB211 I borrowed. I was interested in seeing what a concentric slave looked like close up. Somebody mentioned on the Sideways forum about the 9.3 slave - but that may have been for a GT6. It will not go to waste as I have a Saab 9.3 (I love it) and I may just fit another one to it. It looks on the small side for the TR box; but I haven't played with it yet. Roger Quote Link to post Share on other sites
silverfox4 Posted October 8, 2020 Report Share Posted October 8, 2020 I cant wait to jump on the from the Hydraulic concentric clutch bandwagon, so really looking forward to what you learn from the Saab unit - keep at it. I followed Marco's project with interest but it was maybe a challenging approach and the units he used are difficult to source. Cheers, Alf Quote Link to post Share on other sites
Z320 Posted October 8, 2020 Report Share Posted October 8, 2020 Hi Roger, sadly the TR gearbox shaft diameter is for a tractor and not from a car, its diameter on the splines is about 32 mm!!!! The hydraulic unit for the Saab 9.3 seems to have a 34 mm piston, it's very likely you don't get it over the gearbox shaft. Bleeding also seams a problem to me with this unit. But I hope you tell me I'm wrong! The Sachs unit 318 265 4206 unit I used is for Opel / Vauxhall Omega and has a 35 mm piston, this fits with modifications. This unit is also very easy and for very small money (€50) avivable, I will use it again for my MX5 project. I found some with bigger pistons and more from Mercedes small trucks, but for some 100 of Euros. Wishing you much success. Ciao, Marco Quote Link to post Share on other sites
Bob Smith Posted October 9, 2020 Report Share Posted October 9, 2020 I have a couple of original unused Stanpart taper pins 158777 if anybody needs one. I no longer have a need for a spare pin as my TR has been sold. Quote Link to post Share on other sites
RogerH Posted October 9, 2020 Author Report Share Posted October 9, 2020 1 hour ago, Bob Smith said: I have a couple of original unused Stanpart taper pins 158777 if anybody needs one. I no longer have a need for a spare pin as my TR has been sold. That would be a great trial project. To make a rig that would actuate the clutch 50,000 or 60,000 times in a few days or so to see when the pin failed. But were the OEM shafts and forks better than today. rather a lot of variables. Roger Quote Link to post Share on other sites
RogerH Posted October 9, 2020 Author Report Share Posted October 9, 2020 10 hours ago, Z320 said: Hi Roger, sadly the TR gearbox shaft diameter is for a tractor and not from a car, its diameter on the splines is about 32 mm!!!! The hydraulic unit for the Saab 9.3 seems to have a 34 mm piston, it's very likely you don't get it over the gearbox shaft. Bleeding also seams a problem to me with this unit. But I hope you tell me I'm wrong! The Sachs unit 318 265 4206 unit I used is for Opel / Vauxhall Omega and has a 35 mm piston, this fits with modifications. This unit is also very easy and for very small money (€50) avivable, I will use it again for my MX5 project. I found some with bigger pistons and more from Mercedes small trucks, but for some 100 of Euros. Wishing you much success. Ciao, Marco Hi Marco, the 9.3 diameter was noted immediately it came out of the box. But that is not a problem. There tends to be a lot of waste in R&D. It gives me a feel for the project simply to have something solid in my hands. I'll investigate your Sachs unit and see how it develops. Roger Quote Link to post Share on other sites
Z320 Posted October 9, 2020 Report Share Posted October 9, 2020 research & development ? Quote Link to post Share on other sites
Ian Vincent Posted October 9, 2020 Report Share Posted October 9, 2020 19 hours ago, RogerH said: Hi Peter, Before I left the worlds #1 airline I did a stock take. I don;t think I will run out unless I do a full NDT of the RB211 I borrowed. I was interested in seeing what a concentric slave looked like close up. Somebody mentioned on the Sideways forum about the 9.3 slave - but that may have been for a GT6. It will not go to waste as I have a Saab 9.3 (I love it) and I may just fit another one to it. It looks on the small side for the TR box; but I haven't played with it yet. Roger You could alwys fit a saloon box with its smaller input shaft. Rgds Ian Quote Link to post Share on other sites
PodOne Posted October 9, 2020 Report Share Posted October 9, 2020 I know you all like a project and this may sound a bit stupid but if the pins are the weak spot why not fit the pin and braze/weld the fork to the shaft. If the bushes fail (not looked at my box to check) can the shaft be pull back inside while the bushes are replaced or will the input shaft prevent this? Feel free to say I'm talking C....!! Tin hat on. Andy Quote Link to post Share on other sites
RogerH Posted October 9, 2020 Author Report Share Posted October 9, 2020 Hi Andy, one of the repairs carried out when you are on the road is to pull the GB back a touch and then weld the shaft insitu. When you need to sort it out proper you need to cut the shaft. So much easier to support the taper pin with another method. Roger Quote Link to post Share on other sites
Z320 Posted October 16, 2020 Report Share Posted October 16, 2020 Hi Roger, did you have some time for a closer look? I'm interested about your experience about the Saab unit. Ciao, Marco Quote Link to post Share on other sites
ChrisR-4A Posted October 19, 2020 Report Share Posted October 19, 2020 (edited) The concentric clutch method is obviously the ultimate solution, however I am a believer in keeping it simple with as many original parts as possible and a kit which could solve the problem and be fitted by the average home mechanic would be ideal. To this end the following may be worth considering 1. Fix the fork by the normal method. 2. Cut the cross shaft about 3ins pertruding from the fork on LH (lever side). 3. Weld or braze the fork to shaft. 4. Have a machine shop produce a sleeve with 2 inch long internal splines, a split end and a pinch bolt. and cut mating splines on the remaining rh half of the shaft. Weld sleeve to cross shaft next to fork, or cut splines and clamp. The RH half could be assembled from the inside outwards and the LH side could be slid in from the LH outside as normal, pushed into the female splined sleeve and clamped up. Chris Edited October 19, 2020 by ChrisR-4A Quote Link to post Share on other sites
billy l Posted October 19, 2020 Report Share Posted October 19, 2020 3 hours ago, ChrisR-4A said: The concentric clutch method is obviously the ultimate solution, however I am a believer in keeping it simple with as many original parts as possible and a kit which could solve the problem and be fitted by the average home mechanic would be ideal. To this end the following may be worth considering 1. Fix the fork by the normal method. 2. Cut the cross shaft about 3ins pertruding from the fork on LH (lever side). 3. Weld or braze the fork to shaft. 4. Have a machine shop produce a sleeve with 2 inch long internal splines, a split end and a pinch bolt. and cut mating splines on the remaining rh half of the shaft. Weld sleeve to cross shaft next to fork, or cut splines and clamp. The RH half could be assembled from the inside outwards and the LH side could be slid in from the LH outside as normal, pushed into the female splined sleeve and clamped up. Chris That's keeping it simple? Cheers, Bill. Quote Link to post Share on other sites
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