Casar66 Posted January 29 Author Report Share Posted January 29 I thought exactly the same way. But lets wait and see until the ordered Vcoil-Set arrives. I won't go under the car again before. Quote Link to post Share on other sites
Steve 286 Posted January 29 Report Share Posted January 29 This is what I use. Quote Link to post Share on other sites
Casar66 Posted January 29 Author Report Share Posted January 29 How did you extend the drill? Quote Link to post Share on other sites
Steve 286 Posted January 29 Report Share Posted January 29 I used a length of 12 mm bar drilled a hole in the centre using my lathe turned the drill round held it back in the chuck and put a bit of weld on it Quote Link to post Share on other sites
Casar66 Posted January 29 Author Report Share Posted January 29 Now I'm confused a bit: the manual states 5/16 UNF as the thread. I have ordered a VCoil set 5/16 × 24. And now I have also discovered a 5/16 × 18 set. Which is the right one? Quote Link to post Share on other sites
stuart Posted January 29 Report Share Posted January 29 5/16 x 24 is UNF the other is UNC. Stuart. Quote Link to post Share on other sites
Steve 286 Posted January 29 Report Share Posted January 29 As Stuart says 5/16 x 24 the 24 is 24 threads per inch is also written on the front of my helicoidal picture I sent to you Quote Link to post Share on other sites
Casar66 Posted January 29 Author Report Share Posted January 29 Ah got it. UnF is Fine thread. Thanks. Quote Link to post Share on other sites
rcreweread Posted January 29 Report Share Posted January 29 I think I must be missing something here, but I thought the bolts holding the sump on were UNC not UNF - happy to be corrected - maybe I've got the wrong bolts! Cheers Rich Quote Link to post Share on other sites
rcreweread Posted January 29 Report Share Posted January 29 1 hour ago, rcreweread said: I think I must be missing something here, but I thought the bolts holding the sump on were UNC not UNF - happy to be corrected - maybe I've got the wrong bolts! Cheers Rich Whoops - spotted my error - this post is about the 6 cylinder engines on which the sump bolts are UNF - on 4 cylinders they are UNC Cheers Rich Quote Link to post Share on other sites
Jonny TR6 Posted January 29 Report Share Posted January 29 55 minutes ago, rcreweread said: Whoops - spotted my error - this post is about the 6 cylinder engines on which the sump bolts are UNF - on 4 cylinders they are UNC Cheers Rich That’s very geeky Rich, but very impressive ! Quote Link to post Share on other sites
rcreweread Posted January 29 Report Share Posted January 29 Just now, Jonny TR6 said: That’s very geeky Rich, but very impressive ! Jonny - not sure about geeky, more like stupid - I should stick to what I know best, the 4 pots. At least I spotted my mistake before anyone else pointed it out so I saved a bit of embarrassment! Cheers Rich Quote Link to post Share on other sites
Steve 286 Posted January 29 Report Share Posted January 29 Don’t worry rich I will remind you at the next breakfast meeting Quote Link to post Share on other sites
mleadbeater Posted January 31 Report Share Posted January 31 just for info, you can get a long T handle tap wrench, this may help with your tapping. ebay link: https://www.ebay.co.uk/itm/144024857139 Mike Quote Link to post Share on other sites
RogerH Posted January 31 Report Share Posted January 31 Hi Mike, that looks nice. More Christmas presents Roger Quote Link to post Share on other sites
mleadbeater Posted January 31 Report Share Posted January 31 Go on, treat yourself, life’s too short! Quote Link to post Share on other sites
DenisMc Posted January 31 Report Share Posted January 31 (edited) Hi Casar66, Just adding to the advice you have been given. A few years ago I did a similar repair on my TR5 using a helicoil at the front of the engine where there is an aluminium bridge piece. The biggest problem I faced was getting access to drill the tapping hole and tapping the thread. For the tapping drill, the special helicoil drill is 8.3 mm in diameter. I bought an 8.00mm diameter drill, which has a 1/4" hexagonal drive (Bosch HSS Impact), then used a long extension in a drill similar to these that a friend had: https://www.ebay.co.uk/itm/166437203294?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=132-gjzjq1i&sssrc=2047675&ssuid=dRwPbWsuRay&widget_ver=artemis&media=COPY Although the drill was 0.3mm less in diameter than the helicoil tapping drill, tapping into the soft aluminium was fine. I bought one of these extensions from eBay: https://www.ebay.co.uk/itm/155376972079?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=ieousdxtq-u&sssrc=2047675&ssuid=dRwPbWsuRay&var=455580083734&widget_ver=artemis&media=COPY This enabled me to mount the tap and tap the hole for the helicoil thread insert, swinging it beneath the sump. I used grease on the tap to catch the swarf. I did the same when I broke off the helicoil tang and managed to remove it from the hole, washing it out will some WD 40. I hope that this helps and good luck. Edited January 31 by DenisMc Quote Link to post Share on other sites
mleadbeater Posted January 31 Report Share Posted January 31 big variation between your tap wrench and the one I found, wonder if they’re identical ? Quote Link to post Share on other sites
DenisMc Posted January 31 Report Share Posted January 31 Quite possibly they are! It is often worth shopping about Quote Link to post Share on other sites
Casar66 Posted February 1 Author Report Share Posted February 1 Quote For the tapping drill, the special helicoil drill is 8.3 mm in diameter. I bought an 8.00mm diameter drill, which has a 1/4" hexagonal drive (Bosch HSS Impact), then used a long extension in a drill similar to these that a friend had: https://www.ebay.co.uk/itm/166437203294?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=132-gjzjq1i&sssrc=2047675&ssuid=dRwPbWsuRay&widget_ver=artemis&media=COPY And the hole was really accurate with this extension? I had already thought of something like this, but rejected it again, as there is always a bit of play. The statement that the 8mm drill bit in aluminum also works with the helicoil is very helpful. Because then I could also use a normal 8mm drill extension. Or is it just the little bit of play with the bit extension that makes the 8mm hole a little wider? Quote Link to post Share on other sites
DenisMc Posted February 1 Report Share Posted February 1 (edited) The end of the helicoil tap is tapered and slightly less than 8mm in diameter. In all probability, as you say, an 8 mm drill held in an extension and mounted in a hand held drill will probably cut larger in diameter particularly at the start. I was fortunate to have the use of a pit and had a friend stand behind me and to the side to ensure that the drill entered the hole at right angles to the sump flange as possible. The aluminium alloy used is quite soft and with a little upward force had no difficulty in getting the tap to start, again whilst being guided by a friend. I took my time turning the tap half to three quarters of a turn at a time then reversing it slightly to break off the cut metal. It is worth noting that a stripped 5/16" UNF internal thread is going to be close to 8mm in diameter anyway. I hope that this helps! Edited February 1 by DenisMc Quote Link to post Share on other sites
Steve 286 Posted February 1 Report Share Posted February 1 I’ve seen people who have got an 8mm bolt and just wound it straight in it does hold but not the sort of thing I would do or advise Quote Link to post Share on other sites
Casar66 Posted February 3 Author Report Share Posted February 3 Today the Vcoil thread set arrived and I checked the length of the drill and it seemed that it could work without an extension. But I had a look at the TR6 repair manual again. And read fore the first time that the 4 bolts at the sump's rear should be longer than the other 19. But my 23 ones are all the same length. So with a very close look at the ( in deed blind) hole I saw that only the first threads are gone but there were many good ones left. So all it need was a 1/4 inch longer srew. Sorry for a lot of fuss about nothing. Quote Link to post Share on other sites
Andy Moltu Posted February 3 Report Share Posted February 3 Take the sump off and do it properly. The fiddly hassle of trying to squeeze past the sump, removal of swarf ect outweighs the cost of 6L of oil and a sump gasket. On the bench its easy to fit a helicoil. Quote Link to post Share on other sites
Chilliman Posted February 3 Report Share Posted February 3 1 hour ago, Casar66 said: Today the Vcoil thread set arrived and I checked the length of the drill and it seemed that it could work without an extension. But I had a look at the TR6 repair manual again. And read fore the first time that the 4 bolts at the sump's rear should be longer than the other 19. But my 23 ones are all the same length. So with a very close look at the ( in deed blind) hole I saw that only the first threads are gone but there were many good ones left. So all it need was a 1/4 inch longer srew. Sorry for a lot of fuss about nothing. A good result Quote Link to post Share on other sites
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