boxofbits Posted July 28, 2020 Report Share Posted July 28, 2020 Evening all Hope you're all well. I'm in need of a 1st/2nd gear selector fork, and also a reverse selector fork for a TR4a, or has anyone got a decent used complete set or even NOS set, or know where I can source them ? Had to drill out bolts during work to change shaft seals which were leaking badly? I could possibly use the reverse fork but there is still some movement between male/female thread even with new bolts, so don't want to risk it. The 1st/2nd fork thread is also worn too badly just to replace the bolt. There was slight rocking movement between bolt and threaded hole even before dismantling. Do they make a very slightly oversized bolt/pin so that the thread can be recut with a tap I wonder as, as long as the pin is the same diameter I don't think it would matter? Regards Kevin Quote Link to post Share on other sites
RogerH Posted July 28, 2020 Report Share Posted July 28, 2020 Hi Kevin, I have a similar problem on an older TR box. I am considering putting a helicoil into them. The major problem is drilling the hole square and central. So I will be making a jig to set it up in the mill/drill. 7/16UNF I think. Roger Quote Link to post Share on other sites
boxofbits Posted July 28, 2020 Author Report Share Posted July 28, 2020 (edited) 14 minutes ago, RogerH said: Hi Kevin, I have a similar problem on an older TR box. I am considering putting a helicoil into them. The major problem is drilling the hole square and central. So I will be making a jig to set it up in the mill/drill. 7/16UNF I think. Roger Yes it'd have to be bang on square to go into the shaft. Not a job for yer standard Black and Decker hand held! I checked the threads last night and they are 5/16" UNF. I'm wondering if someone could turn up some slightly oversized bolts so that the original holes can be tapped square in a machine shop? It would only need to be 1/32 - 1/16" enough for a new thread wall ? I think I'd also get the heads drilled for locking wire as I'd hate to see the mess if one dropped into the box at 70mph! Kevin Edited July 28, 2020 by boxofbits Quote Link to post Share on other sites
John Morrison Posted July 28, 2020 Report Share Posted July 28, 2020 Got a spare gearbox cover complete if thats of interest. John. Quote Link to post Share on other sites
boxofbits Posted July 28, 2020 Author Report Share Posted July 28, 2020 30 minutes ago, John Morrison said: Got a spare gearbox cover complete if thats of interest. John. Many thanks John that’s of interest. How good is it do you know? You could definitely see the oil shifting in the threads on mine when the forks were rocked with the shafts held tight. How much would you want for it btw? Regards Kevin Quote Link to post Share on other sites
JJC Posted July 28, 2020 Report Share Posted July 28, 2020 I have a 3 synchro box looking for a home (free).JJC Quote Link to post Share on other sites
John Morrison Posted July 28, 2020 Report Share Posted July 28, 2020 2 hours ago, boxofbits said: Many thanks John that’s of interest. How good is it do you know? You could definitely see the oil shifting in the threads on mine when the forks were rocked with the shafts held tight. How much would you want for it btw? Regards Kevin I'll dig it out in the morning, and have a dekko. Cover the postage Kevin, and its yours. John. Quote Link to post Share on other sites
Lebro Posted July 29, 2020 Report Share Posted July 29, 2020 +1 for the helicoil idea Bob. Quote Link to post Share on other sites
RogerH Posted July 29, 2020 Report Share Posted July 29, 2020 (edited) Hi Kev, One of my forks had a broken wedgelok that I had to drill out. I damaged about 1/4 of the circumference of the threads. I managed to pass a 5/16UNF tap down the full depth. Then used the tap shank n the lathe chuck to sit into the vice square. I could then drill the helicoil hole and then re-tap to fit the helicoil That was the easy part !!! The helicoil took some persuading to start in the hole but managed to get it in. problems - do not insert the helicoil too far - I had to file a small amount of helicoil off the bottom to allow the rod to pass through - but it does fie. The helicoils come n multiples of hole diameter 1/2D, 1D, 1,5D, 2D 1/2D would be a fraction too small 1D is 2 coils to long. However it is not too difficult to remove the extra coils with a flush face side cutter. This may leave a coil not in the Bronze threads. This can simply be forced into place So a fairly easy job IF you have enough fork thread to pick up on, you have a drill/mill with a decent vice. The wedgloks ARE 5/16UNF - recently I found a 7/16UNF wedgy - could it be on a gear cluster of something deep in the GB. Roger Roger Edited July 29, 2020 by RogerH Quote Link to post Share on other sites
JJC Posted July 29, 2020 Report Share Posted July 29, 2020 I keep saying this. I’ve got a 3 synchro box free o anyone who can collect it from deepest Dorset. It Must be good for parts. Eventually I’ll put it on eBay or the tip. JJC Quote Link to post Share on other sites
boxofbits Posted July 29, 2020 Author Report Share Posted July 29, 2020 On 7/28/2020 at 10:33 PM, John Morrison said: I'll dig it out in the morning, and have a dekko. Cover the postage Kevin, and its yours. John. Hi John Many thanks for your offer to send me a gearbox top cover. State of play at the moment is that Roger has kindly offered to fit uprated seals to my existing unit and a guy called Mike Papworth believes he has some very good used forks, so plan is to repair mine, but IF this does not turn out to be a solution is it okay if I come back to you? Much appreciated John. Regards Kevin Quote Link to post Share on other sites
boxofbits Posted July 29, 2020 Author Report Share Posted July 29, 2020 11 minutes ago, JJC said: I keep saying this. I’ve got a 3 synchro box free o anyone who can collect it from deepest Dorset. It Must be good for parts. Eventually I’ll put it on eBay or the tip. JJC As per my reply to John Morrison many thanks for your offer. I’m hoping I can repair my original unit as someone has some good spares but certain there must be a taker for your box as it must have some valuable parts! Thanks again. regards Kevin Quote Link to post Share on other sites
John Morrison Posted July 29, 2020 Report Share Posted July 29, 2020 27 minutes ago, boxofbits said: Hi John Many thanks for your offer to send me a gearbox top cover. State of play at the moment is that Roger has kindly offered to fit uprated seals to my existing unit and a guy called Mike Papworth believes he has some very good used forks, so plan is to repair mine, but IF this does not turn out to be a solution is it okay if I come back to you? Much appreciated John. Regards Kevin No worries Kevin, hope you get sorted. John. Quote Link to post Share on other sites
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