BSF Posted July 20, 2013 Share Posted July 20, 2013 The rear axle hubs on my Series 2B rebuild have a number of studs missing and the threaded holes are in poor condition, does anyone know the correct drill size to make the hole accept the later knock-in studs? Quote Link to comment Share on other sites More sharing options...
David Sparkes Posted July 21, 2013 Share Posted July 21, 2013 Possibly one of those 'not helpful' replies, unless it encourages someone to produce the required information, because more than one person can make use of it :-) I understood the required hole size to be 9/16", but haven't seen that verified in an engineering sense. The vehicle I'm currently working on has one wheel stud missing. Yesterday I examined the hub more closely, and saw the thread was stripped. I tested it by making a trial fit of a new threaded stud (a spare left over from another vehicle). The threaded section of the new stud just pushed in, but did stop as the plain section of stud reached the hub. I now realise I neglected to check whether the 'stop' was due to the slightly increased diameter of the plain section, or whether there was a slight remnant of un-stripped thread in the hub, that stopped the threaded end of the new stud. With that slight proviso in mind, it did occur to me that a hole that was threaded 9/16 BSF, but from which the thread has now stripped, needs little or no further preparation. Hopefully of interest, if not fully helpful. Quote Link to comment Share on other sites More sharing options...
Snagger Posted July 21, 2013 Share Posted July 21, 2013 My studs are all splined at their bases, and their holes had corresponding splines. If the hole was plain, the stud would spin when you tried to do up the nuts. I'd be a bit wary of re-using a hub where a stud had pulled out - there may be more stress damage than just the stripped thread that can't be seen by eye. A replacement hub should be easy and cheap enough to source. Quote Link to comment Share on other sites More sharing options...
Phil Hancock Posted July 21, 2013 Share Posted July 21, 2013 The stud holes in hubs that were made for drive fit studs were only splined from the fitting of the stud which is harder than the hub. I would measure with a micrometer the unsplined portion of the stud and that is the size for the holes, its smaller than the top of the splines. The flange on the threaded stud hubs are thinner than for the drive fit, the drive fit has the 'head' in a counterbore which is then peened to prevent the stud dropping back out, so when replacing drive fit studs in place of screwed the 'head' will be in fresh air. Quote Link to comment Share on other sites More sharing options...
BSF Posted July 22, 2013 Author Share Posted July 22, 2013 The problem was not that the stud had pulled out, just that the thread is worn out by someone just continuing to use the stud and seized nut as a bolt and screwing it into and out of the hub which, as has been observed, is of softer metal. Quote Link to comment Share on other sites More sharing options...
Phil Hancock Posted July 22, 2013 Share Posted July 22, 2013 How about a very high tensile 9/16" BSF bolt screwed in from the rear to replace the stud with plenty of loctite stud lock to stop it turning. This had been done on my 88" before i bought it back in 76. Quote Link to comment Share on other sites More sharing options...
BSF Posted July 26, 2013 Author Share Posted July 26, 2013 From observation about half the studs have already been replaced by the imperial knock-in type, which look ok. In the meantime I have found the hubs in good condition that I removed from the front (I have fitted Heystee disc brakes), so the problem is partly answered. However, not fully as the fronts now have metric studs and nuts and the rear imperial. I'll just have to carry two wheelbraces. Quote Link to comment Share on other sites More sharing options...
missingsid Posted July 29, 2013 Share Posted July 29, 2013 I used knock in studs in a screw in flange for years and were much safer than the screw in ones which vibrated loose at upper speed limits! theey were an in field repair with a hammer, round file to remove remaining thread and the hole in the back body capping as a support for the hub.. Marc. Quote Link to comment Share on other sites More sharing options...
Phil Hancock Posted July 29, 2013 Share Posted July 29, 2013 From observation about half the studs have already been replaced by the imperial knock-in type, which look ok.In the meantime I have found the hubs in good condition that I removed from the front (I have fitted Heystee disc brakes), so the problem is partly answered. However, not fully as the fronts now have metric studs and nuts and the rear imperial. I'll just have to carry two wheelbraces. Dont forget that the drums that came off wont now fit the replacement hubs as the metric studs are a larger diameter. Quote Link to comment Share on other sites More sharing options...
danster Posted July 30, 2013 Share Posted July 30, 2013 got the same problem with my 2a original stud part number 561590 is the screw in one 561886 is the knock in one then you can use the original wheel nut and a 9/16ths drill bit to drill the hub. should have double checked the thread in my hubs before i ordered new ones from craddocks ordered screw in ones but the thread is fubared on 2 of them so will be replacing them with knock in ones Quote Link to comment Share on other sites More sharing options...
BSF Posted August 31, 2013 Author Share Posted August 31, 2013 Dont forget that the drums that came off wont now fit the replacement hubs as the metric studs are a larger diameter. No drums going on, just nice new Defender discs! Quote Link to comment Share on other sites More sharing options...
Jessie the dog Posted May 13, 2020 Share Posted May 13, 2020 Hi there, I have posed a similar question in another thread. I am in the same situation where I am replacing the original double ended stud on my 1959 S2. Its fine opening up the hole to accept a knock in or pull up stud, however there is a fundamental problem with that from what I can see. The original studs were 46mm long. The knock in type are 42mm long and then you have 4mm of shoulder, so net 38mm long. That doesn’t leave enough thread for a full nut. The answer is perhaps to counterbore the back of the hub, but that isn’t straightforward and would require hub removal and decent equipment. Given how easy everyone seems to be finding this swap, I think i must be missing something. Or is there a longer knock in stud available? Quote Link to comment Share on other sites More sharing options...
92a Posted May 14, 2020 Share Posted May 14, 2020 Longer studs are available on Paddocks website, I've just had to put some in the rear of a series 3 that is going to be fitted with thicker "wolf"rims, Quote Link to comment Share on other sites More sharing options...
Jessie the dog Posted May 14, 2020 Share Posted May 14, 2020 10 minutes ago, 92a said: Longer studs are available on Paddocks website, I've just had to put some in the rear of a series 3 that is going to be fitted with thicker "wolf"rims, Hi there, were they 9/16”? I have seen 16mm (M16?) studs Quote Link to comment Share on other sites More sharing options...
92a Posted May 14, 2020 Share Posted May 14, 2020 M16 , I thought you were going over to knock in ones ? FRC7577 60mm , but not 9/16 R Quote Link to comment Share on other sites More sharing options...
Anderzander Posted May 14, 2020 Share Posted May 14, 2020 You can get longer 9/16 studs - but they are very expensive I understand. If you have the double ended nuts, then the cheaper alternative would be to use to use the early BSF half nuts ... or is that what you are already using? Taking the hub off isn’t that big a job though - so I wouldn’t be put off doing that ..? Quote Link to comment Share on other sites More sharing options...
Romahomepete Posted May 18, 2020 Share Posted May 18, 2020 I think the problem with the BSF standard pull in studs is aesthetics rather than safety. There is more than enoughof the stud in the double ended nut to be safe but they just dont look right and have been the cause (wrongly) of MOT failures in the past. They look OK with the BSF half nuts. Peter Quote Link to comment Share on other sites More sharing options...
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