TriumphV8 Posted November 27, 2015 Report Share Posted November 27, 2015 Yes, but that does not fit! Quote Link to post Share on other sites
RogerH Posted November 27, 2015 Author Report Share Posted November 27, 2015 (edited) oops!! I made an error - it is 5/8" x 13TPI - this does not exist. M16 x 2 is very close but not spot on. Hi Bob, yes 5/8 UNC is 11 TPI - but I got that wrong. Roger Edited November 27, 2015 by RogerH Quote Link to post Share on other sites
Lebro Posted November 27, 2015 Report Share Posted November 27, 2015 (edited) BSF is 14 TPI BSW & UNC are 11 TPI M16 is 12.7 TPI, & 0.6299" Dia (5/8 = 0.625") Hard to believe it's Metric, but that does seem to be the nearest http://www.practicalmachinist.com/vb/general-archive/odd-size-tap-die-help-77913/ http://mdmetric.com/thddata.htm 13 TPI does not exist !! Bob. Edited November 27, 2015 by Lebro Quote Link to post Share on other sites
RogerH Posted November 27, 2015 Author Report Share Posted November 27, 2015 Hi Bob, that is what I found - 13tpi just doesn't exist. I shall go for the 16 x 2mm and see what happens. Roger Quote Link to post Share on other sites
graeme Posted November 28, 2015 Report Share Posted November 28, 2015 Hi Bob, that is what I found - 13tpi just doesn't exist. I shall go for the 16 x 2mm and see what happens. Roger Roger, Buckeye Triumphs used M16x2 with success. http://www.buckeyetriumphs.org/technical/Gearbox/ODSwitches/ODSwitches.htm Cheers Graeme Quote Link to post Share on other sites
RogerH Posted November 28, 2015 Author Report Share Posted November 28, 2015 (edited) Hi Graeme, thanks for that. The evidence would suggest M16 is the thread type - but why? Standard TRiumph had all sorts of UK/USA thread sizes to choose from. Perhaps the switch itself is off the shelf in France (Metric) or wherever and that is what they used. Anyway, the M16 tap is on order. Now to work out where my interlock balls went and how to get new ones in. Roger Edited November 28, 2015 by RogerH Quote Link to post Share on other sites
TriumphV8 Posted November 28, 2015 Report Share Posted November 28, 2015 As I told the thread is really 5/8 13TPI and my sugestion to M16 x 2 was done because I had it at hand and it fitted although the thread gauge showed a little difference even on that short thread that only covers half of the gauge. When done in a greater batch nearly every thread can be made without bigger expense. But to be honest, this was real nonsense, 5/8 UNC would have been the thread to choose..... Especially this coarse thread combined with the fibre washers for distance setup tends to get loose and more than once oil popped out of that area...... So maybe that was the reason to swap from 11TPI to 13TPI to keep the rule that aluminium cast takes UNC & get a bigger force against turning loose. Anyway, in the rear axle flange they use UNF....... Quote Link to post Share on other sites
MichaelH Posted November 28, 2015 Report Share Posted November 28, 2015 I used the metric tap and it worked I agree that metric sound like nonsense as original Triumph but I had a friend with an extensive range of taps (he is a steam enthusiast) and this was the tap I ended up with and the switch goes in and works BTW there is no oil on the other side with the side application as in my photo Good Luck maybe should be Bon Chance Michael Quote Link to post Share on other sites
RogerH Posted November 28, 2015 Author Report Share Posted November 28, 2015 Hi Andreas/Michael, logic suggests that the switch must have been from a continental source - hence metric (but it is not spot on metric). ST wouldn't have wasted money making or commissioning their own switch. Roger Quote Link to post Share on other sites
Graham Harris Posted November 28, 2015 Report Share Posted November 28, 2015 Hi Roger, I have just redone the selector shaft O ring seals because they were still leaking. The reason was the seal area on the shafts had some seriouse pitting and would not stop the oil. As a sort of bodged fix i filed the shaft with a mill bastard file then emery tape to clean it up and got ride of the pitting. The diameter is a little smaller by a few thou but the O rings are slightly compressed when you fit them so i am hoping they will now do the job. Graham. Quote Link to post Share on other sites
RogerH Posted November 28, 2015 Author Report Share Posted November 28, 2015 Hi Graham, that is very interesting. I noted some marks on my shafts. I haven't checked to see what they are etc. My o-rings appeared a little slack on the shaft and the new O-rings do not appear any better. Annoyingly the shaft can't be sleeved as it has to go inside the casting. I may have found a lip seal that will fit - it is perfect except all the dimension are a little out . They arrive early next week so I may have a play. My O-rings were leaking big time. I have read some old posts were there is mention of pressurisation and venting etc.as the oil gets hot it must cause some pressurisation. There is a breather on the OD that looks oily but don;t know if it works - I shall remove and investigate. I spotted that Peejay4A drilled a hole in the front nearside of the box - did this help. Roger Quote Link to post Share on other sites
peejay4A Posted November 28, 2015 Report Share Posted November 28, 2015 (edited) It most certainly did help Roger. I have a J type overdrive and IIRC they don't have a breather. My gearbox top cover was not drilled and I suffered leaking big time. The breather hole in the top cover has reduced it to normal TR levels. (ie it now leaks from other places under gravity). Edited November 28, 2015 by peejay4A Quote Link to post Share on other sites
RogerH Posted November 28, 2015 Author Report Share Posted November 28, 2015 Hi Pete, have you any information on what you did - hole size, position etc any pics. Roger R Quote Link to post Share on other sites
stuart Posted November 28, 2015 Report Share Posted November 28, 2015 Roger if its any help I have the correct drill and tap for the gearbox switches. Stuart.. Quote Link to post Share on other sites
peejay4A Posted November 28, 2015 Report Share Posted November 28, 2015 (edited) Hi Pete, have you any information on what you did - hole size, position etc any pics. Roger R Trying to find them... Here it is: It's just visible below the upper extreme right bolt hole. Edited November 28, 2015 by peejay4A Quote Link to post Share on other sites
TriumphV8 Posted November 28, 2015 Report Share Posted November 28, 2015 Hi Andreas/Michael, logic suggests that the switch must have been from a continental source - hence metric (but it is not spot on metric). definitely not metric, its precise 13tpi, not 2mm metric. I have both gauges at hand and tested it. Quote Link to post Share on other sites
TriumphV8 Posted November 28, 2015 Report Share Posted November 28, 2015 I spotted that Peejay4A drilled a hole in the front nearside of the box - did this help. The non OD box has the breather in the rear gearbox extension and no hole in the gearbox cover If somebody swaps to OD later an additional hole must be drilled in the front bearing that supports the left shaft for shifting. That is the place with the least oil from rotating wheels inside. If forgotten the gearbox pops oil out whenever warmed up. Same problem may occure when a OD gearbox receives a new cover that came from a non OD box. I found it helpfull to drill the hole and add a tube with a 8mm rubber hose along the speedo cable that ends at the distributor to avoid oil being pressed out of the breather. What pops out keeps in the hose and is sucked back into the gearbox when box gets colder. Quote Link to post Share on other sites
RogerH Posted November 28, 2015 Author Report Share Posted November 28, 2015 (edited) Hi Andreas, I agree about the 'not metric' statement - it isn;t quite there. But there are NO 13 TPI threads in the whole universe - very odd. Hi Pete, thanks for the pic. Hi Stuart, I have a tap winging its way here for Tuesday/Wednesday. Is yours M16x2mm Sorting these O-rings was filling me with dreaded but having attacked it it is actually quite easy. The WM has got the disassembly wrong - is states to remove the centre shaft first - not possible. Re-assembly is correct - insert centre shaft first. The buckeye process is too wordy. My version - Remove lid Undo the three wedgelock screws. Great fun. Remove outer shaft - and catch the ball. Remove inner shaft - and catch the ball Remove the centre shaft - and catch the roller. Unscrew the two seal plate screws. Remove the seals. Assembly is neat as it looks as if nothing will fit Fit the seals and the seal plate. Fit greased roller into centre shaft and insert shaft into lid with spacer and selector. Pop some grease on top of the roller in the outer shaft position. Insert the inner shaft (where there is no ball) . Place a ball over the roller and push in as far as it will go. The inner shaft will stop the roller popping out. Remove the inner shaft. Insert the outer shaft where the ball has just been inserted plus the spacer and selector. Pop some grease on the roller in the inner shaft hole and locate the ball. The ball should push across out of the way from the shaft. Insert the inner shaft fitting the spacer and selector. I wonder what I've left out. It really is simple. Roger Edited November 28, 2015 by RogerH Quote Link to post Share on other sites
Lebro Posted November 28, 2015 Report Share Posted November 28, 2015 Quote Link to post Share on other sites
RobH Posted November 28, 2015 Report Share Posted November 28, 2015 (edited) Hi Andreas, I agree about the 'not metric' statement - it isn;t quite there. But there are NO 13 TPI threads in the whole universe - very odd. Actually there are (or perhaps were) An American National Coarse thread (ANC 1/2 inch) was 13 tpi. according to my 1956 issue of the Engineers Reference Book. Edited November 28, 2015 by RobH Quote Link to post Share on other sites
stillp Posted November 28, 2015 Report Share Posted November 28, 2015 1/2" UNC, according to this: http://www.engineershandbook.com/Tables/uncunfthreadsperinch.htm Quote Link to post Share on other sites
Lebro Posted November 28, 2015 Report Share Posted November 28, 2015 Yes, but no 5/8" X 13 TPI Quote Link to post Share on other sites
RogerH Posted November 29, 2015 Author Report Share Posted November 29, 2015 Just to clarify - we are looking for a thread form that is apprx 5/8" with 13TPI. M16 is apprx 5/8" and it has apprx 13TPI - but not exactly (but is as close as can be sorted at present) 13 TPI does exist in other thread sizes but the switch would either all out or not fit. Roger Quote Link to post Share on other sites
stuart Posted November 29, 2015 Report Share Posted November 29, 2015 Right the tap I have is 5/8" X 13TPI. Stuart. Quote Link to post Share on other sites
RogerH Posted November 29, 2015 Author Report Share Posted November 29, 2015 Hi Stuart, was that specially made? Roger Quote Link to post Share on other sites
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