DanielH Posted December 13, 2022 Report Share Posted December 13, 2022 Good evening everybody, I have started working on my GT6+'s gearbox and OD. I thought it would be a good idea to post my progress here and to somehow involve you in my enterprise... It's the second gearbox which I am restoring. The XJ6 gearbox I did 15 years ago is still working and silent 😉 I've bought the GT6 gearbox from a Frenchman last year, it has the serial # KE1954 and comes with a D-Type overdrive. Thanks for your input 🙂 Greetings from Germany Daniel Link to comment Share on other sites More sharing options...
DanielH Posted December 13, 2022 Author Report Share Posted December 13, 2022 The box is gutted, I have the repair kit from R1mmers, and the parts are on my desk. My first question evolves around the synchro rings. The repair kit comes with 4 repro rings. A couple of things strike me when I compare the old ones with the repros: friction surface: OLD: Repro: The friction surface looks different, right? The repro groove patterns appear shallower. The locking keys also look slightly different: left REPRO(!), right OLD They appear bolder on the OLD part. Would you exchange this old ring with the repro ring? I guess I have to check the other old rings for wear. Thanks 🙂 Link to comment Share on other sites More sharing options...
DanielH Posted December 13, 2022 Author Report Share Posted December 13, 2022 The clearance between the ring and the mating part is ca. 0,029in (ca. 0,75mm). The workshop manual doesn't contain info about hwo to check the rings for wear, doesn't it? The repro rings don't slide over 😞 That's pretty miserable... Link to comment Share on other sites More sharing options...
DanielH Posted December 13, 2022 Author Report Share Posted December 13, 2022 This ring is shot: no gap at all! The other 2 rings have a 0,03in+ gap. The grooves feel also quite sharp. Fortunately I've still got the original (non-OD) gearbox of the car, I guess I will pick one or two good rings from it. What do you say? Link to comment Share on other sites More sharing options...
johny Posted December 13, 2022 Report Share Posted December 13, 2022 One thing, the three rail gearbox used two different designs of synchro ring during its life. The early ones are part number 148409 and they have a smaller internal diameter than the later synchros 150328 so are not interchangeable. Your car would have used the early type while the later Mk3 GT6 (KE serial number gearboxes) had the bigger ones which would explain why the new rings you have wont fit on the cones... Link to comment Share on other sites More sharing options...
Clive Posted December 13, 2022 Report Share Posted December 13, 2022 23 minutes ago, DanielH said: This ring is shot: no gap at all! The other 2 rings have a 0,03in+ gap. The grooves feel also quite sharp. Fortunately I've still got the original (non-OD) gearbox of the car, I guess I will pick one or two good rings from it. What do you say? The wise gearbox builders often use good secondhand synchros. And swap them about, first and second, and 3rd and 4th. You can use some fine abrasive to remove the shine from cone surface and then feel teh synchros to see which works best on each cone. Link to comment Share on other sites More sharing options...
DanielH Posted December 13, 2022 Author Report Share Posted December 13, 2022 Ohhhh... My original gearbox is a KD... my "french" gearbox is KE, which is newer. So you are saying that I cannot re-use my synchronizer rings of my KD gearbox, right? Link to comment Share on other sites More sharing options...
johny Posted December 13, 2022 Report Share Posted December 13, 2022 Well you cannot be 100% sure because gearboxes have been modified over the years (the later bigger synchro rings last longer and work better then the originals) but yes youre right the KD should have the smaller rings the same as in the kit. The rings are common to various Triumph (and other makes) models with the small ones being used in all Heralds, Spitfire 1, 2, 3, Vitesse 1 & 2 and GT6 1, 2, 2+ while the larger were in GT6 III, Spitfire IV & 1500 (single rail) plus other models.... Link to comment Share on other sites More sharing options...
Josef Posted December 13, 2022 Report Share Posted December 13, 2022 The testing Clive mentions is to put the ring on a gear and try and turn it. Push the ring harder against the gear and feel how much pressure is required before it becomes hard / impossible to turn. If you have a really worn one it will still move even if you’re pushing it against the gear as hard as you can. Link to comment Share on other sites More sharing options...
johny Posted December 14, 2022 Report Share Posted December 14, 2022 9 hours ago, johny said: The rings are common to various Triumph (and other makes) models with the small ones being used in all Heralds, Spitfire 1, 2, 3, Vitesse 1 & 2 and GT6 1, 2, 2+ while the larger were in GT6 III, Spitfire IV & 1500 (single rail) plus other models.... The good news is that all the other components in your overhaul kit should be good for the later gearbox👍 Link to comment Share on other sites More sharing options...
68vitesse Posted December 14, 2022 Report Share Posted December 14, 2022 Delt with Mike Papworth, Coventry, and Overdrive Repair Services, Sheffield, when I broke the overdrive gearbox in my Vitesse several years ago. Some teeth came of third gear on the cluster. Found both very helpful with advice and good quality spares. Regards Paul. Link to comment Share on other sites More sharing options...
Pete Lewis Posted December 14, 2022 Report Share Posted December 14, 2022 the repro baullk rings look pretty awfull are they even going to be round , many were made in a lathe chuck and they are lobed where the jaws comressed them one very important part of synchro mesh is the accurate and well definde tooth chamfer on the ring the gear dog teeth and the sleeve these chamfer's side flanks are what keeps the ring in "rock over" till rotational loads synchronise any worn or chimmbled teeth will allow a crash as you change gear as the ring will let go thro' the change attached i a Rootes explaination which is the best i can find 1 Link to comment Share on other sites More sharing options...
johny Posted December 14, 2022 Report Share Posted December 14, 2022 Yes Im still waiting for a report back on how well these pattern part synchro rings work from someone who has rebuilt a gearbox with them? I suspect NOS or even good used originals are preferable but for Daniel in Germany thats not going to be easy.... Link to comment Share on other sites More sharing options...
johny Posted December 14, 2022 Report Share Posted December 14, 2022 Although this 150328 offering from Bastuck in Germany at 14.46€ (incl VAT) might be a good alternative.... Link to comment Share on other sites More sharing options...
DanielH Posted December 14, 2022 Author Report Share Posted December 14, 2022 Hi there, I have ordered another (repro?) ring from a different supplier here in Germany, since the other three of my rings appear in good shape. NOS is unobtainable, isn't it? Link to comment Share on other sites More sharing options...
JumpingFrog Posted December 14, 2022 Report Share Posted December 14, 2022 8 minutes ago, DanielH said: Hi there, I have ordered another (repro?) ring from a different supplier here in Germany, since the other three of my rings appear in good shape. NOS is unobtainable, isn't it? I wouldn't say NOS is unobtainable, but unfortunately your best bet is to watch British eBay for several months, they come up every now and again. They really shouldn't be that rare when you consider the same parts were fitted to lots of relatively common cars (Midget 1500, Ital, Marina as well as Triumph models). I think used is your best bet if the repro ring turns out bad, but ideally you need to try a few and select the best as others mentioned earlier. In my experience 1st and 2nd wear most, 3rd and 4th not so much. Canley Classics in the UK sell used rings for a fair price - https://canleyclassics.com/?diagram=triumph-spitfire-mkiv/1500-constant-pinion-countershaft-and-reverse-shaft-gears&ptno=150328R 1 Link to comment Share on other sites More sharing options...
Pete Lewis Posted December 14, 2022 Report Share Posted December 14, 2022 i paid a premium withRB for supposed high quality german baulk rings for the 2000 box rebuild and they are not that special quite poor really and not on the quality , next year i wil likely refit the old ones if i get the inspiration to drag the box off , its not the best car for a quick box swap round as they need a heck of a drop to get at the top C hsg bolts with a lot of extn on the socket Pete Link to comment Share on other sites More sharing options...
Josef Posted December 14, 2022 Report Share Posted December 14, 2022 I’ve one new County ring from Paddocks in my Herald’s box (YC ex 1500 RWD) which looked OK, felt OK on the gear and is performing without issue so far. 1 Link to comment Share on other sites More sharing options...
thescrapman Posted December 15, 2022 Report Share Posted December 15, 2022 23 hours ago, johny said: The good news is that all the other components in your overhaul kit should be good for the later gearbox👍 One thing to watch, Mk3 GT6 gearbox has a different gearset to Mk2. Gear angles are different. Dolomite 1850 3-rail is same gearset as Mk3 GT6. 1 Link to comment Share on other sites More sharing options...
Pete Lewis Posted December 15, 2022 Report Share Posted December 15, 2022 yes the tooth profile changed to improve noise you cant mix or you get a real whiner Pete Link to comment Share on other sites More sharing options...
johny Posted December 15, 2022 Report Share Posted December 15, 2022 Not to mention different size synchro rings in the same box😂 Link to comment Share on other sites More sharing options...
DanielH Posted December 15, 2022 Author Report Share Posted December 15, 2022 Good evening 🙂 I am about to check the countershaft end float. I've inserted the new needle rollers into it. It appears the 24 rollers should go on each side, right? Link to comment Share on other sites More sharing options...
DanielH Posted December 15, 2022 Author Report Share Posted December 15, 2022 Here are the new and old washers side by side: Link to comment Share on other sites More sharing options...
johny Posted December 15, 2022 Report Share Posted December 15, 2022 should be 25 rollers each side. New thrusts look ok although looks like the design is slightly different for the smaller one but the part that takes the load is the same size👍 The manual says to set the laygear end float by selecting the correct thrust washers to give between 0.178 and 0.330 mm clearance. If your outside of this you could remove metal from the back of a washer or if loose make a shim.... 1 Link to comment Share on other sites More sharing options...
DanielH Posted December 15, 2022 Author Report Share Posted December 15, 2022 ok, I am going to correct the rollers, I have to take one from the old set, since I've already used up all new rollers.. 😞 well The end float: Both new thrusts are too thick, cannot get them in. End float with both old thrusts is ca 0,01377in (0,35mm). Shall I keep the old ones, or adjust the new ones? What is your advise here? Link to comment Share on other sites More sharing options...
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