Z320 Posted November 21, 2021 Report Share Posted November 21, 2021 (edited) Hi there, yesterday I had a visit from my friend Jochem to have a closer look on his new gearbox. My MX-5 project has been diskussed at the German TR-Freunde and he has been told the Rover LT77 gearbox with Rover V8 bell fits more easy. The gearbox bell is bolted to the gearbox, has a very characteristic shape and is easy to identify. It is fixed with 6 M12x40 bolts, 2 of them go through dowel bushes. The lower part on the right side is for the rover clutch mechanism. INDEED! The gearbox bell fits perfect on my TR4A engine! The dowels and all bolts fit perfect. But folks - that all that fits..... The part of the bell for the clutch mechanism could touch the exhaust. This is 0 - 15 mm too low. Because the Rover clutch mechanism is different and it would touch the exhaust pipe and the oil pan we have to fit an concentric release unit. Jochem already wanted to go this way on his TR gearbox. It will look like this on my old TR gearbox, it is out of use since I use the MX-5 gearbox. But the gearbox cover of the ingoing shaft is completely different from the TR cover we can’t use the unit I already made for Jochem. I suggested Jochem to sell the hole unit and built it new, to swop it means too many good TR parts remain needless in the workshop. A close look on the front of the LT77, please notice the ingoing shaft is not in the correct position because the gearbox is empty! Pulled in the correct position the shaft fits the pilot bearing - but the splined part touches it because it is about 5 mm too long. No fit, we have to turn it shorter on the lathe. Not my part, I don't get it though my lathe... With the gearboxes in the same position It is obvious the gear shifter is about 160 mm in the wrong position! Meens: this gearbox would fit a Mazda MX-5 NA/NB perpaps better than a TR The outgoing flange of the gearbox fits the TR probshaft perfectly - but the probshaft is about 90 mm to short for the LT77! Also no fit: the rear gearbox mounts, very likely the crossmenber to the frame also does not fit. After 2 hours comparing, measuring and calculating we had each one 2 pots of coffee and 2 pieces of my lovley wifes plum cake. To tell you the truth: we both have been a little disappointed, but we get this project working because others also got it working. But "easy to fit" is story telling. Ciao, Marco Edited November 24, 2021 by Z320 Quote Link to post Share on other sites
JochemsTR Posted November 21, 2021 Report Share Posted November 21, 2021 Thank you Marco for this introduction in our little project. It made most sense to me, looking for help from Marco since he proved lots of time his engineering skills and creativity. Which in this case, are needed once more again. Eventhough the complexity compared to the Mazda Gearbox is manageable, yet some items remain. In this case the Shifter Housing need to be shortened. A friend in the german TR Forum mentioned Sherpa Van has a reduced housing. Maybe someone here can confirm or has any other ideas of solving this particular problem. I look forward to the discussions. Quote Link to post Share on other sites
BlueTR3A-5EKT Posted November 21, 2021 Report Share Posted November 21, 2021 Stag prop shaft is about 4” or 100mm longer than a TR item and has the same sized flanges as TR. Peter W Quote Link to post Share on other sites
JochemsTR Posted November 21, 2021 Report Share Posted November 21, 2021 (edited) 29 minutes ago, BlueTR3A-5EKT said: Stag prop shaft is about 4” or 100mm longer than a TR item and has the same sized flanges as TR. Nice! Or using 2 45mm spacers on each side to extend the TR propshaft. Edited November 21, 2021 by JochemsTR Quote Link to post Share on other sites
Z320 Posted November 21, 2021 Author Report Share Posted November 21, 2021 The outgoing flang is holded in position by a oily rag, my choice is making two xy mm spacers Quote Link to post Share on other sites
Waldi Posted November 21, 2021 Report Share Posted November 21, 2021 Could you add a 15-20 mm spacer between GB en bell housing? This avoids modification of the GB ingoing shaft. Or will it make other issues worse? Waldi Quote Link to post Share on other sites
Z320 Posted November 21, 2021 Author Report Share Posted November 21, 2021 Makes the shifter lever more in the wrong position! Quote Link to post Share on other sites
JochemsTR Posted November 21, 2021 Report Share Posted November 21, 2021 16 minutes ago, Waldi said: This avoids modification of the GB ingoing shaft. The shaft only requires 4-5 mm which I need to remove on a lathe. This is a relativ small issue. Bringing the shifter housing forward is the main issue. Quote Link to post Share on other sites
Waldi Posted November 21, 2021 Report Share Posted November 21, 2021 Ok, good luck with it. Waldi Quote Link to post Share on other sites
Z320 Posted November 21, 2021 Author Report Share Posted November 21, 2021 (edited) Hi there, I have no hope to find a „ready to fit“ shifter housing, we have to cut a 160 mm piece out and weld it together again, to find out about the mechanism below is the first step to find out. Any advice or photos are welcome. Cheers, Marco Edited November 21, 2021 by Z320 Quote Link to post Share on other sites
Z320 Posted November 22, 2021 Author Report Share Posted November 22, 2021 (edited) Hi, indeed Jörg from the German TR-Freun.de forum (thank you) gave us the advice to have a look on the "very short" shifter houing from the Leyland Sherpa van. Comparing photos the Sherpa housing indeed is very short, I guess the shifter lever is 2 - 3 cm too far forward... But very interesting is what the Sherpa has below the housing. I found another photo (the internet is my friend), it's simply a cranked ball joint. As the connections below the shifter housing are also simple ball joints Another photo shows how it finally could look like. Today I opended the empty gearbox to install the shifter shaft. And I gave some attention on the rubbers and how the shifter housing should be fixed on the gb. I suggest Jochem to make this rubbers from aluminium for a fix fit, so he can anyway use PU or rubber ones. Because we loose the rear mount fixing the housing with rubber mounts will be very „flexible“. Ciao, Marco Edited November 23, 2021 by Z320 Quote Link to post Share on other sites
Z320 Posted November 23, 2021 Author Report Share Posted November 23, 2021 they look like this now it was possible to measure exactly with a dummy shifter lever + before I cut the housing in pieces I have to find out the dimension of this offset and make a connector Quote Link to post Share on other sites
Z320 Posted November 24, 2021 Author Report Share Posted November 24, 2021 Hi, after determine the offset I decided to cut the housing in pieces first to send it to Jochem and his welder. I know some of you don't value the result of using a hack saw... Working with this tool 1st you need is patience, 2nd patience and finally ...patience. This way the housing is shipped tomorrow, the parts 2, 3, 4 are for the welder to do some exercise and variation of the welder setting. Quote Link to post Share on other sites
Z320 Posted November 25, 2021 Author Report Share Posted November 25, 2021 Hi, this evening I checked the Sachs hydraulic release bearing I made for Jochem for his TR gearbox some time ago. There is to much to change to fit it on the LT77 gearbox and too many TR specific parts remain not needed. This is why I make him a new on and ordered a unit via eBay. Ciao, Marco Quote Link to post Share on other sites
Z320 Posted November 26, 2021 Author Report Share Posted November 26, 2021 (edited) some measurements and calculations today, a phone call with Jochem talking about the reverse lock mechanism and another part ordered at eBay today Edited November 26, 2021 by Z320 Quote Link to post Share on other sites
Z320 Posted November 27, 2021 Author Report Share Posted November 27, 2021 (edited) Today I wanted to make the excentric connector on the lathe, but by my fault I crashed the drill rod. A new one is ordered but the lathe is blocked because I can't undo the chuck until the drilling is finished. So I hade a closer lock on the gearbox's rear mount on my dummy frame, the crossmember and rubber mount are in the position they will be on the cars frame. Sadly the rear end of the LT77 gearbox is too low for the TR original crossmember and rubber mount (40 mm high). With a bar of flat steel 40x5 mm, slightly angled the gearbox could be fixed very easy - but will lift the rear end about 25 mm. In my opionion the fastest way to get to a result for a first test - and could work. With the rear end not lifted there is only about 23 mm space for a rubber mount and an angled bar of flat steel. You may notice the wedged gap between the gearbox and the crossmember? Well, the aluminium surface is parallel to the gearbox shaft, perpaps the engine and gearbox are horizontal in a Rover and on the frame. But on our TRs the engine and gearbox is wedged - while the surface of the frame is horizontal. This is why the rear end of the TR gearbox is angled my TR gearbox on the photo is horizontal on a the work bench). This is a steel sheet "connecting bar", about xx deg angled, just to test, not solid enough this way. In position, gap to the crossmember to fit anything made of vulcanised rubber between is only 20 mm. Any idee what could fit? Or use the original TR mount and lift the end of the gearbox 25 mm? Andreas (V8) - how did you solve this, please? Ciao, Marco Edited December 19, 2021 by Z320 Quote Link to post Share on other sites
JochemsTR Posted November 30, 2021 Report Share Posted November 30, 2021 in the mean time...parts were blasted and browned. I am starting to get really fond of this finish. Quote Link to post Share on other sites
Z320 Posted November 30, 2021 Author Report Share Posted November 30, 2021 (edited) Did you fix it with some oil? I love browning too. Edited November 30, 2021 by Z320 Quote Link to post Share on other sites
BlueTR3A-5EKT Posted November 30, 2021 Report Share Posted November 30, 2021 (edited) On 11/27/2021 at 10:59 PM, Z320 said: Today I wanted to make the excentric connector on the lathe, but by my fault I crashed the drill rod. A new one is ordered but the lathe is blocked because I can't undo the chuck until the drilling is finished. So I hade a closer lock on the gearbox's rear mount on my dummy frame, the crossmember and rubber mount are in the position they will be on the cars frame. Sadly the rear end of the LT77 gearbox is too low for the TR original crossmember and rubber mount (40 mm high). With a bar of flat steel 40x5 mm, slightly angled (about 10°) the gearbox could be fixed very easy - but will lift the rear end about 25 mm. In my opionion the fastest way to get to a result for a first test - and could work. With the rear end not lifted there is only about 23 mm space for a rubber mount and an angled bar of flat steel. You may notice the wedged gap between the gearbox and the crossmember? Well, the aluminium surface is parallel to the gearbox shaft, perpaps the engine and gearbox are horizontal in a Rover and on the frame. But on our TRs the engine and gearbox is wedged about 10° - while the surface of the frame is horizontal. This is why the rear end of the TR gearbox is angled about 10% (my TR gearbox on the photo is horizontal on a the work bench). This is a steel sheet "connecting bar", about 10° angled, just to test, not solid enough this way. In position, gap to the crossmember to fit anything made of vulcanised rubber between is only 20 mm. Any idee what could fit? Or use the original TR mount and lift the end of the gearbox 25 mm? Andreas (V8) - how did you solve this, please? Ciao, Marco Which TR chassis is this to fit in.? Remember after 1973 TR6 moved the gearbox mounting bracket down 20mm and backwards 50 mm. This was to fit the J type overdrive. https://www.moss-europe.co.uk/shop-by-model/triumph/tr5-6/clutch-transmission-drivetrain/gearboxes-components/engine-gearbox-mountings-tr5-6-1967-76.html PS. I have a spare Chuck. You can swap it and maintain concentricity of mounted work. Edited November 30, 2021 by BlueTR3A-5EKT Quote Link to post Share on other sites
stuart Posted November 30, 2021 Report Share Posted November 30, 2021 1 minute ago, BlueTR3A-5EKT said: Which TR chassis is this to fit in.? Remember after 1973 TR6 moved the gearbox mounting bracket down 20mm and backwards 50 mm. This was to fit the J type overdrive. https://www.moss-europe.co.uk/shop-by-model/triumph/tr5-6/clutch-transmission-drivetrain/gearboxes-components/engine-gearbox-mountings-tr5-6-1967-76.html Doesnt help on a 4a though the J Type chassis brackets used to be available. I have converted a CP Chassis to a CR by changing the brackets. Stuart. Quote Link to post Share on other sites
Z320 Posted November 30, 2021 Author Report Share Posted November 30, 2021 Thank you both to indicate on this, I thought the diff is mainly the same from 4A - 6, the probshaft too, the 4 speed gearbox anyway (mainly). And the additional lenght of the 6 cylinder engine goes forward, reverse is not possible because the head would touch the bulkhead. So the bracket welded on all TR4-TR6 frames should be in the same position - and the difference for OD TRs is the different crossmenber bolted between? Is this not the case? Ciao, Marco Quote Link to post Share on other sites
stuart Posted November 30, 2021 Report Share Posted November 30, 2021 (edited) 22 minutes ago, Z320 said: Thank you both to indicate on this, I thought the diff is mainly the same from 4A - 6, the probshaft too, the 4 speed gearbox anyway (mainly). And the additional lenght of the 6 cylinder engine goes forward, reverse is not possible because the head would touch the bulkhead. So the bracket welded on all TR4-TR6 frames should be in the same position - and the difference for OD TRs is the different crossmenber bolted between? Is this not the case? Ciao, Marco No the gearbox bracket for all "A" type and non overdrive gearboxes be it in a 4a/5 or 6 is in the same place (Engine mounts obviously change but the gearbox flange at the bulkhead is the same) its only on CR or early 73 on TR6 when the "J" type overdrive was fitted (and also the standard non overdrive on those models) that the chassis mounting brackets were changed and moved back and down. The propshaft also remains the same for the whole TR range just with a shape of flange change early on. To go with the change to "J" Type the bracket that bolts to the chassis and the associated mounting rubbers etc were also changed. Stuart. Edited November 30, 2021 by stuart Quote Link to post Share on other sites
JochemsTR Posted November 30, 2021 Report Share Posted November 30, 2021 (edited) 7 hours ago, BlueTR3A-5EKT said: Which TR chassis is this to fit in.? in mine, 1973 chassis. I had a non-OD Gearbox, followed by a J-Type OD. If Marco bases his measurements on his TR4a chassis, I do no expect any issues adapting this to my chassis. Or am I wrong in this assumption? Jochem Edited November 30, 2021 by JochemsTR Quote Link to post Share on other sites
Z320 Posted December 1, 2021 Author Report Share Posted December 1, 2021 (edited) Hi Peter and Stuart, thank you again, you saved us a lot of senseless work, sadly I have got no idea how to make the new mount without the correct frame or a frame model, without the J type OD‘s crossmember and without suitable rubber mounts. For the earlier frame I have everything in my workshop and garage…. Ciao, Marco Edited December 1, 2021 by Z320 Quote Link to post Share on other sites
JochemsTR Posted December 1, 2021 Report Share Posted December 1, 2021 Does anyone have a sketch or dimensional difference between the early and late chassis of the gearbox area? Quote Link to post Share on other sites
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