John Morrison Posted October 7, 2022 Report Share Posted October 7, 2022 No problem fitting a B & B TR4A Diaphragm clutch assembly - that is not what you show here. John. Quote Link to post Share on other sites
rcreweread Posted October 7, 2022 Report Share Posted October 7, 2022 (edited) 41 minutes ago, John Morrison said: No problem fitting a B & B TR4A Diaphragm clutch assembly - that is not what you show here. John. Your photo shows a spring clutch arrangement - if you intend to keep this arrangement you will need to use the clutch release bearing and carrier from your old gearbox (as Peter W mentioned in an earlier post) If you plan to swap to a later diaphragm arrangement( as fitted to TR4As), you will have to get your flywheel drilled and tapped to match the mounting holes for a diaphragm clutch cover and you will need to use the relevant bearing and carrier - they are not interchangeable Cheers Rich Edited October 7, 2022 by rcreweread Quote Link to post Share on other sites
Chilliman Posted October 7, 2022 Report Share Posted October 7, 2022 9 hours ago, Moliver said: So my base line is 100% TR4A regarding parts soucring and to my understanding, there are not many options available: I don't think so - probably TR4 but not 4A - the flywheel and clutch assembly in your picture aren't 4A ....what is the engine number? Quote Link to post Share on other sites
BlueTR3A-5EKT Posted October 7, 2022 Report Share Posted October 7, 2022 (edited) 14 hours ago, Moliver said: Hello Peter, Thanks for the feedback. Although a TR2, I do have a TR4A engines fitted. The box has been an original TR2 one, which now will be replaced by a TR4A spec (with OD). So my base line is 100% TR4A regarding parts soucring and to my understanding, there are not many options available: For the release bearing a "heavy duty" version is available, which I have ordered now. The clutch component options available seem to be limited as well: For the disc, B&B seems to be the best option (as the LUK is no longer available, so isn't the Sachs). For the clutch meachanicm I am only aware of a B&B and a Sachs option (10 spline). I assume that I do have a complete B&B kit (mechanicm and disc) fitted - picture attached. I have ordered a new B&B disc and have to options for the mechanism a) keep the B&B which seems to be quite new and just replace the disc to a B&B b) replace by a Sachs mechanicm (with new B&B disc) Input appreciated Regards Oliver That is a spring type clutch cover….count the springs that create the clamping pressure all 9 of them. The release bearing is flat faced so suitable for a spring type clutch cover. Release bearing carrier looks like a bronze type so probably the original for the spring type clutch. It is shorter than the ones used on diaphragm clutch of TR4A. If you remove the 8 hex head screws that hold the clutch cover to the flywheel the friction plate will come out…note which way round it is fitted as the bit with the springs in should be away from the flywheel. Measure it. You will find it to be 9 inches diameter. The TR4A plate is smaller at 8 1/2 inches. Same centre splines though. The clutch cover is located by 2 dowels on the spring type cover you have and 3 on a diaphragm type. The diaphragm type is also smaller diameter so the bolt holes in the flywheel will not line up. Solution to get your car working. Check the wear on the clutch friction plate. Renew with same type if needed. Check the spline of the clutch plate fits your new gearbox. Check the release bearing for smooth running. Transfer it and it’s carrier to your new gearbox. Check the gearbox rebuilder has double pinned or bolted the clutch operating fork to the cross shaft. If not do it. Check the thickness of the gearbox bell housing flange at the top where the 3 studs come through. You may need longer studs if it is a later stronger thick flange casing. If you want to fit the TR4A diaphragm clutch assembly your engine flywheel will need to be removed and sent to be drilled and tapped (5/16” unc) plus the 3 dowels, to accept the smaller clutch cover. Or you need to buy a replacement TR4A flywheel. Note. Looking at your starter …You have a later type flywheel that has a bolt on ring gear. Remember that if you intend to replace the starter. You will also need a different clutch release bearing assembly with the correct carrier sleeve. See page 25/26/27 of this for someone doing what you are doing Peter W PS Forgot to re mention the requirement to slot the mounting plate bolt hole to allow the 4 synchro gearbox to be fitted. Following is an image of a diaphragm clutch cover. Very different to the spring type you have. Edited October 7, 2022 by BlueTR3A-5EKT Quote Link to post Share on other sites
Richardtr3a Posted October 7, 2022 Report Share Posted October 7, 2022 That is an impressive answer at this time in the morning. This forum is very valuable Well done Richard & B Quote Link to post Share on other sites
Moliver Posted October 7, 2022 Author Report Share Posted October 7, 2022 Hello All, A lot of information and very helpful- what a great community! The engine number is CT16390 - so TR4 the head is a TR4A high port why I assumed a TR4A spec. Just adjusted the clutch parts order accoringly. The new gear box definitely will be TR4A with OD. The rear mount modification is already completed and I am prepared to modify the tunel cover to consider the casting difference of the starter area. I in this case will just 1:1 replace the clutch disc (B&B) and the clutch release bearing (has made some noise). I am correct, that the TR2-4 release bearing will fit in the TR4A box ?? Anything else I should have forgotten and need to consider ? Cheers Oliver Quote Link to post Share on other sites
Moliver Posted October 7, 2022 Author Report Share Posted October 7, 2022 "Note. Looking at your starter …You have a later type flywheel that has a bolt on ring gear. Remember that if you intend to replace the starter. -> I intend to keep the starter, so no actions here ", so You will also need a different clutch release bearing assembly with the correct carrier sleeve" --> Does this mean, that the TR2-4 release bearing assembly does NOT fit into the TR4A box ? Quote Link to post Share on other sites
rcreweread Posted October 7, 2022 Report Share Posted October 7, 2022 You will need to use the the TR2-4 release bearing and it's carrier if you are keeping the spring clutch - they will fit the 4A gearbox without any trouble Cheers Rich Quote Link to post Share on other sites
BlueTR3A-5EKT Posted October 7, 2022 Report Share Posted October 7, 2022 (edited) 31 minutes ago, Moliver said: "Note. Looking at your starter …You have a later type flywheel that has a bolt on ring gear. Remember that if you intend to replace the starter. -> I intend to keep the starter, so no actions here ", so You will also need a different clutch release bearing assembly with the correct carrier sleeve" --> Does this mean, that the TR2-4 release bearing assembly does NOT fit into the TR4A box ? Correct. The bearing and carrier you have will fit and work with a TR4A gearbox. Just try them on to check the fit and movement. The only change you might come across would have been if you had a gearbox from a saloon car. That is a smaller inner diameter sleeve and bearing and definitely will not fit a TR gearbox (2-6) The release bearing and carrier you currently have are only suitable for use with the spring type clutch you have fitted. Edited October 7, 2022 by BlueTR3A-5EKT Quote Link to post Share on other sites
Moliver Posted October 8, 2022 Author Report Share Posted October 8, 2022 ... I think I now have a vague idea of why 3rd gear had its problems .... Quote Link to post Share on other sites
Lebro Posted October 8, 2022 Report Share Posted October 8, 2022 That's 1st gear, & it looks fine to me, except isn't the hub the wrong way round ? Bob Quote Link to post Share on other sites
Z320 Posted October 8, 2022 Report Share Posted October 8, 2022 2 teeth are missing? Quote Link to post Share on other sites
BlueTR3A-5EKT Posted October 8, 2022 Report Share Posted October 8, 2022 41 minutes ago, Z320 said: 2 teeth are missing? There should be. Quote Link to post Share on other sites
Z320 Posted October 9, 2022 Report Share Posted October 9, 2022 This is on the „sliding part“ of the sleeve? Quote Link to post Share on other sites
Chilliman Posted October 9, 2022 Report Share Posted October 9, 2022 I have to confess that picture confuses the heck out of me, it appears to show the 1st/2nd synchro hub but up against the front of the case? Quote Link to post Share on other sites
Charlie D Posted October 10, 2022 Report Share Posted October 10, 2022 22 hours ago, Chilliman said: it appears to show the 1st/2nd synchro hub but up against the front of the case? Maybe the gearbox was built by Eric Morecambe. ( It has all the right gears, but not necessarily in the right order. ) Charlie. Quote Link to post Share on other sites
Dic Doretti Posted October 10, 2022 Report Share Posted October 10, 2022 Quote Link to post Share on other sites
Chilliman Posted October 10, 2022 Report Share Posted October 10, 2022 Nice.......... Quote Link to post Share on other sites
Tom Chatterley- Cox Posted October 11, 2022 Report Share Posted October 11, 2022 On 10/9/2022 at 10:10 AM, Chilliman said: I have to confess that picture confuses the heck out of me, it appears to show the 1st/2nd synchro hub but up against the front of the case? This is just a 3 synchro box. From the photo, everything looks as it should. The hubs are the other way around + against the back of the casing. 3 synchro boxes have one less physical gear as 1st gear is derived from the teeth on the syncrho hub and the straight teeth on the laygear. Hence the signature whine in 1st gear in all 3 synchro TRs. Incidentally, this usually makes 1st gear the weakest part of 3 synchro boxes, as it shares its teeth with reverse (which also has no synchro mesh) and you always see quite a bit of wear on the leading edge of the straight teeth. I've attached photos of both a 3 and 4 synchro box with the visible differences. Quote Link to post Share on other sites
Chilliman Posted October 11, 2022 Report Share Posted October 11, 2022 Thanks Tom, that now makes complete sense, I'm only familiar with the later all synchro units, hence my confusion..! Quote Link to post Share on other sites
Lebro Posted October 11, 2022 Report Share Posted October 11, 2022 Me too ! Bob Quote Link to post Share on other sites
Nobbysr Posted October 18, 2022 Report Share Posted October 18, 2022 (edited) It does look look like it was thrown together I believe this what a 4 synchro should look like Oddly enough when i took everything apart on mine I found the gear box case is a Triumph Saloon, 4 synchro with the correct overdrive it had a diaphragm clutch cover 8 1/2inch pate but the shorter throw out sleeve, the clutch was fairly good with no signs of slipping. The overdrive is a triumph 2.5 with a Tr4 rear casing I have bought the longer throw out sleeve ready to fit but i'm a it concerned now that should i go back to the original sleeve Top cover has the dipstick and and all of the isolator switches the balls springs etc have been replaced in the selector housing By the way thanks for your help with the parts Tom much appreciated Edited October 18, 2022 by Nobbysr Quote Link to post Share on other sites
billy l Posted October 18, 2022 Report Share Posted October 18, 2022 Don’t forget to wire lock the selector bolts, cheers bill Quote Link to post Share on other sites
BlueTR3A-5EKT Posted October 18, 2022 Report Share Posted October 18, 2022 The longer sleeve with the domed faced release bearing is correct for the 8 1/2” diaphragm clutch assy. Not the shorter sleeve. Quote Link to post Share on other sites
Nobbysr Posted October 18, 2022 Report Share Posted October 18, 2022 Thanks Peter i would have thought that the shorter one wouldn't have worked, but i guess that the clutch adjustment could have taken up the the slack..... does that sound feasible .. The clutch was one of the things that actually OK, especially given the fact that cross shaft bushes were also fitted incorrectly and the shaft weakened all the best Steve Quote Link to post Share on other sites
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