Colin Lindsay Posted October 18, 2021 Report Share Posted October 18, 2021 Anyone know the type of thread used on the steering wheel to column nut, 105438, as used on most of our cars of the era? The threads on some of my columns are badly deformed and I want to retap them, but can find plenty of nuts for sale, just not the spec. Link to comment Share on other sites More sharing options...
PeteH Posted October 18, 2021 Report Share Posted October 18, 2021 Pure guess?. 1" AF?. the nut looks about 23/24mm at a glance?. Pete Link to comment Share on other sites More sharing options...
Jeffds1360 Posted October 18, 2021 Report Share Posted October 18, 2021 9/16 x28 unified...... or so an old post entitled "steering boss thread" from June 20 seems to say?? Link to comment Share on other sites More sharing options...
Colin Lindsay Posted October 19, 2021 Author Report Share Posted October 19, 2021 To quote that one: "After some careful measuring I think the early thread is 9/16 x 28-UNIFIED. 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." I hadn't remembered that thread but it narrows down to a range of likely suspects, not the exact thread. It's not the nut, which I can buy easily enough, but the tops of a couple of Herald steering columns that have become distorted, so I want to clean those up before fitting any nut. I don't have a die in that size so it's to avoid visiting the In-Laws and dragging the entire workforce around a bench for an hour with all kinds of charts, thread files and gauges while they all debate over coffee and then blame me for keeping them back. Link to comment Share on other sites More sharing options...
NonMember Posted October 19, 2021 Report Share Posted October 19, 2021 It's worth a try re-measuring. I note that 9/16" UNEF is only 24 TPI but that's probably the most likely candidate. Link to comment Share on other sites More sharing options...
PeteH Posted October 19, 2021 Report Share Posted October 19, 2021 Typical!!. Cannot find my "Zeuss" charts!!. Sod`s law!. I think, from remote memory, 9/16 UNF was indeed 24TPI?. It`s a 60 deg thread form?. Which would make (about) 1mm pitch? If you need a (very) rough check? Just to complicate matters, Some online sources State 9/16 UNF to be 18TPI! (1.4mm pitch) and 3/8 UNF is 24 TPI. I may get the definitive later. IF I can find the OLD steering column. Which got "archived" when I put the PAS unit in. Pete Link to comment Share on other sites More sharing options...
Colin Lindsay Posted October 19, 2021 Author Report Share Posted October 19, 2021 I've lost one complete with steering wheel that I rebuilt a while back. It's got a leather steering wheel cover that I wanted for my latest Herald, but I can't find it. Wheel and cover, column, new bushes, stalks and housings, all renovated... and all missing. Hence the reason for having to remake another, which has worn threads... Link to comment Share on other sites More sharing options...
chrishawley Posted October 19, 2021 Report Share Posted October 19, 2021 Can't generalise as variations across the years (e.g. dolly not same a gt6) but 9/16 Whitworth is definitely one that was used commonly. Whit's 12tpi on 9/16. For unified on 9/16 UNC is 12tpi, UNF is 18 tpi and UNEF 24tpi. If 105438 was for GT6 then Whit is the most likely. Whit and UNC can be hard to tell apart but they are not interchangeable due to the different thread form. Link to comment Share on other sites More sharing options...
Pete Lewis Posted October 19, 2021 Report Share Posted October 19, 2021 the column is surely a fine thread TPI whit is very coarse with the carry over from ages past BSF wouls seem a better gamble the nut is not listed in the Triumph hardware catalogue http://www.leacyclassics.com/media/catalog/product/cache/1/image/360x/1eb0f016ae51377728a4e772f71f785d/1/0/105438_1.JPG Link to comment Share on other sites More sharing options...
Colin Lindsay Posted October 19, 2021 Author Report Share Posted October 19, 2021 105438 was used on everything from TR4 5 and 6 right through to Heralds and Spitfires, also GT6. 24 vehicle variants according to some sites. Superseded part numbers are also 310-530 and 12-098 but so far not one site has listed the actual spec. Link to comment Share on other sites More sharing options...
Pete Lewis Posted October 19, 2021 Report Share Posted October 19, 2021 on a US TR forum its confirmed as 9/16" x 28tpi UNF some nut AF change over the years but the shaft thread has been pretty common for ever on the big saloon /stag range seems same nut but spline/taper is larger Pete Link to comment Share on other sites More sharing options...
andybeau Posted October 19, 2021 Report Share Posted October 19, 2021 zeus.pdf zeus.pdf 1 Link to comment Share on other sites More sharing options...
68vitesse Posted October 19, 2021 Report Share Posted October 19, 2021 From Vitesse WSM. Regards Paul. Link to comment Share on other sites More sharing options...
Colin Lindsay Posted October 19, 2021 Author Report Share Posted October 19, 2021 I don't have that in ANY of my manuals... Link to comment Share on other sites More sharing options...
Stratton Jimmer Posted October 19, 2021 Report Share Posted October 19, 2021 I have the same manual - part number 512947 - and that is the only reference to the dimension of the nut. Group 4 shows it on a diagram but simply refers to it as "steering wheel nut" with no further detail given. Link to comment Share on other sites More sharing options...
Rabbit Posted October 19, 2021 Report Share Posted October 19, 2021 I could possibly be wrong here but several years ago I looked into this. Apparently, the thread is a cycle thread which could be (memory again) 24, 26 or 28 TPI. They were made (outsourced) by a firm producing cycle parts. Once again, I could be wrong but somewhere I have a 28TPI fine cycle thread die which I used with success! 1 Link to comment Share on other sites More sharing options...
PeteH Posted October 19, 2021 Report Share Posted October 19, 2021 That would compare with what I found too. I dug out the old 13/60 column and my thread gauges. The Thread is 28TPI and 55deg thread form. The O/D is 9/16". But the Nut (strangely) is a dead ringer for 27mm!. 27mm Is near to 5/8 bsf?. But a better fit is 1-1/16AF. However British Cycle thread. 9/16" is only 26TPI and a 60Deg thread form?. Pete Link to comment Share on other sites More sharing options...
Pete Lewis Posted October 19, 2021 Report Share Posted October 19, 2021 any idea its whitworth has to be a classic Triumph Typo as 9/16" BSW is 12TPI a right coarse thread form and less than half the measured 9/16 x 28TPI if the nut was 12TPI it would be well chunky , but its a nice fine thread one reason gorilla's have managed to strip so many Pete Link to comment Share on other sites More sharing options...
PeteH Posted October 19, 2021 Report Share Posted October 19, 2021 BSF. is only 16 TPI. so that don`t fit Either!. No BSP sizes come anywhere near?. Browsing the "net" I have come across reference to UNFS? which is allegedly Unified Special threads. But nothing (so far) matches 9/16 x 28TPI?. I thought in a 60 year, world wide, career I had come across them all. It exists, I have one, but what? I am unsure?. And this comes up on E-Bay (Australia). https://www.ebay.co.uk/itm/152292227571 If the threads are still in reasonable condition A BSP (28TPI) thread file might restore to an acceptable standard?. (1/8BSP is 28TPI but only 3/8" (9mm) O/D) Pete Link to comment Share on other sites More sharing options...
RogerH Posted October 19, 2021 Report Share Posted October 19, 2021 9/16" UNS can be 28tpi - look at the TRacy Tools webpage https://www.tracytools.com/taps-and-dies/brass-cycle-special?page=2 Roger Link to comment Share on other sites More sharing options...
RogerH Posted October 19, 2021 Report Share Posted October 19, 2021 4 hours ago, 68vitesse said: From Vitesse WSM. Regards Paul. The manuals have been known to be wrong 9/16"Whit is 12tpi Roger Link to comment Share on other sites More sharing options...
PeteH Posted October 19, 2021 Report Share Posted October 19, 2021 9 minutes ago, RogerH said: 9/16" UNS can be 28tpi - look at the TRacy Tools webpage https://www.tracytools.com/taps-and-dies/brass-cycle-special?page=2 Roger I saw that. But the website is "potentially compromised". So I declined to look. But the Australian E-Bay item suggests likewise. that UNS (special) sizes are "out there". I suspect they will be 60deg thread form?. Pete Link to comment Share on other sites More sharing options...
RogerH Posted October 19, 2021 Report Share Posted October 19, 2021 1 hour ago, PeteH said: I saw that. But the website is "potentially compromised". So I declined to look. But the Australian E-Bay item suggests likewise. that UNS (special) sizes are "out there". I suspect they will be 60deg thread form?. Pete They are a standard (60 degree) UNF thread form but with a special TPI Roger Link to comment Share on other sites More sharing options...
68vitesse Posted October 19, 2021 Report Share Posted October 19, 2021 Found this. http://www.triumphspitfire.com/Torque.html#Steering Regards Paul Link to comment Share on other sites More sharing options...
Colin Lindsay Posted October 19, 2021 Author Report Share Posted October 19, 2021 So: 9/16 UNF sounds good to me. I'll be able to confirm by tomorrow lunchtime provided I don't get thrown out of the workplace for keeping people away from the more important stuff. As if there is any. Link to comment Share on other sites More sharing options...
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