NickTruman Posted April 11, 2020 Report Share Posted April 11, 2020 Hi everyone does anyone know what thread the steering boss lock but is? It’s some sort of 9/16” fine thread by the looks of it. is it unf? Need a nut! by the way, had to source a steering wheel boss, and wasn’t going to pay crazy BB money, turns out a 16mm Mazda ones fits perfectly Link to comment Share on other sites More sharing options...
NonMember Posted April 11, 2020 Report Share Posted April 11, 2020 The nut for all but late 1500 Spitfire is part number 105438, available from Canley or Paddocks for a few quid Link to comment Share on other sites More sharing options...
NickTruman Posted April 11, 2020 Author Report Share Posted April 11, 2020 44 minutes ago, NonMember said: The nut for all but late 1500 Spitfire is part number 105438, available from Canley or Paddocks for a few quid Thank you do you know what size thread it is? Link to comment Share on other sites More sharing options...
Mad4classics Posted April 12, 2020 Report Share Posted April 12, 2020 Looks like 9/16-24 UNEF at a guess, but I haven't got a tap or die that size to verify it. David Link to comment Share on other sites More sharing options...
Nigel Clark Posted April 12, 2020 Report Share Posted April 12, 2020 According to the the factory WSM, it's 9/16" Whitworth, torque to 28-30 lb ft. Nigel Link to comment Share on other sites More sharing options...
NickTruman Posted April 12, 2020 Author Report Share Posted April 12, 2020 Thanks everyone, as it’s not a common size there is no point buying a tap, so I bought a nut instead. Link to comment Share on other sites More sharing options...
Mad4classics Posted April 12, 2020 Report Share Posted April 12, 2020 1 hour ago, Nigel Clark said: According to the the factory WSM, it's 9/16" Whitworth, torque to 28-30 lb ft. Nigel OK, are we all talking about the same 105438 thread because the boss nut is pretty fine and certainly not 9/16-12 Whitworth. (Whitworth 1/2" tap next to boss nut). I think you're better of buying the nut. David Link to comment Share on other sites More sharing options...
Nigel Clark Posted April 12, 2020 Report Share Posted April 12, 2020 13 minutes ago, Mad4classics said: OK, are we all talking about the same 105438 thread because the boss nut is pretty fine and certainly not 9/16-12 Whitworth. (Whitworth 1/2" tap next to boss nut). I think you're better of buying the nut. David Strange, the WSM definitely says 9/16" Whit, but I see what you mean about the Whitworth thread being coarser. Nigel Link to comment Share on other sites More sharing options...
Nigel Clark Posted April 12, 2020 Report Share Posted April 12, 2020 Could it be 9/16" BSF perhaps, the fine version of the Whitworth thread form? Nigel Link to comment Share on other sites More sharing options...
NickTruman Posted April 12, 2020 Author Report Share Posted April 12, 2020 4 minutes ago, Nigel Clark said: Could it be 9/16" BSF perhaps, the fine version of the Whitworth thread form? Nigel I have that tap, it’s much bigger than the thread on the column Link to comment Share on other sites More sharing options...
Nigel Clark Posted April 12, 2020 Report Share Posted April 12, 2020 This is quite a mystery. Unusual for the factory WSM to be wrong but in this case it appears to be. Nigel Link to comment Share on other sites More sharing options...
Pete Lewis Posted April 12, 2020 Report Share Posted April 12, 2020 its odd the 2000 wsm torques shows as 11/16 whit and 1" 1/16" its no way a course whit thread the GT6/Vit shows as 9/16" whit these are 1 /1/16" is 7tpi 11/16 is 11tpi and 9/16 is 12tpi the nuts are in general all a fine thread so whats going on with triumph typo's i dont get it the nuts down here are definitely FINE threads Link to comment Share on other sites More sharing options...
Adrian Cooper Posted April 12, 2020 Report Share Posted April 12, 2020 To complicate things further, when I changed my steering wheel I thought to complete the job with a new nut too. The one I ordered from Paddocks was the correct type for an early Spitfire but it didn't fit and I had to fish the old one out of the bin. Link to comment Share on other sites More sharing options...
Pete Lewis Posted April 12, 2020 Report Share Posted April 12, 2020 for some misguided reason so many of the hand wheel nuts are abused with chisels and punches rather than a socket to fit , lost count of the annihilated nut faces ive seen over the years its obviously rocket science I mean after all .........its only your steering wheel Pete ..............having a grumpy day Link to comment Share on other sites More sharing options...
dave.vitesse Posted April 12, 2020 Report Share Posted April 12, 2020 The later Spit 1500, 1975 - on, has the same nut as the TR7, 13466, and a similar steering column. If I remember its also the same as the Dolomite and maybe the 2000. The good old parts bin again. Its the heat Pete. Dave Link to comment Share on other sites More sharing options...
NickTruman Posted April 12, 2020 Author Report Share Posted April 12, 2020 1 hour ago, dave.vitesse said: The later Spit 1500, 1975 - on, has the same nut as the TR7, 13466, and a similar steering column. If I remember its also the same as the Dolomite and maybe the 2000. The good old parts bin again. Its the heat Pete. Dave That’s what worries me, knowing my luck I have bought the wrong one. Link to comment Share on other sites More sharing options...
dave.vitesse Posted April 12, 2020 Report Share Posted April 12, 2020 If you have a wiper controlling stalk on the column then it's the later nut that's required. Dave Link to comment Share on other sites More sharing options...
NickTruman Posted April 12, 2020 Author Report Share Posted April 12, 2020 6 minutes ago, dave.vitesse said: If you have a wiper controlling stalk on the column then it's the later nut that's required. Dave Hi Dave there lies my problem. I bought my spit part by part. It is a mid engined spitfire based on a VW Passat with a 1.8t engine and transaxle where your dif is. All I can tell is the steering column nut thread is 14mm 9/16” 😁 Link to comment Share on other sites More sharing options...
NickTruman Posted April 12, 2020 Author Report Share Posted April 12, 2020 1 Link to comment Share on other sites More sharing options...
dave.vitesse Posted April 12, 2020 Report Share Posted April 12, 2020 Understood, It may not be a Triumph part? A picture of the steering column may be useful to all on the forum. Dave Link to comment Share on other sites More sharing options...
Mad4classics Posted April 14, 2020 Report Share Posted April 14, 2020 Hmm.. After some carefull measuring I think the early thread is 9/16 x 28-UNIFIED. I haven't got an example of the later boss thread so can't comment on what that is. The unified thread series covers UNC, UNF, UNEF and several constant pitch series: 4-UN, 6-UN, 8-UN, 12-UN, 16-UN, 20-UN, 28-UN and 32-UN. In amounst my boxes of bits I've found two 5/8 x 28-UN nuts; must be off a car I've had at some point in time; steering column boss maybe? So perhaps not so uncommon a thread. David Link to comment Share on other sites More sharing options...
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