TR Paul Posted April 30, 2017 Report Share Posted April 30, 2017 (edited) Hello, fellow TR6ers, I'm currently having the following problems with the bonnet release mechanism, on Troy, my 1970 TR6: the bonnet is reluctant to open, using either the standard bonnet release cable, or the emergency rod mechanism I fitted several years ago. The one guaranteed way of opening the 'lid' is to drive over a speed hump & pull either the cable or rod (obviously something to do with the bodyshell flexing, & would not be very useful if the car was disabled!). The cable isn't seized, & I keep the Catch plate assembly nicely greased; needless to say the whole mechanism works perfectly with the bonnet open, when I'm tinkering! Could this be a week spring in the catch plate mechanism; if so can it be adjusted/repaired, or do I buy a new Catch Plate Assembly? As ever, your advice would be much appreciated, Best wishes, Paul. Edited April 30, 2017 by TR Paul Quote Link to post Share on other sites
pfenlon Posted April 30, 2017 Report Share Posted April 30, 2017 It seems likely that misalignment may be your problem. you could remove the catch from the bonnet itself and shove it into the lock, then see if the release mechanism is working. Its all a bit self explanatory when you know the result. Good luck with it, Peter. Quote Link to post Share on other sites
Mike C Posted April 30, 2017 Report Share Posted April 30, 2017 (edited) I'd also agree with checking the bonnet alignment first ( not a 5 minute exercise) and the catch spring tension when closing. It's possible previous owner may have a altered or changed the catch spring to try to cure problems with the bonnet opening uncontrollably. If the bonnet lock lacks a firm locking action and springs open uncontrollably when crossing bumps I'd also check to see if bonnet lock spring in the lock plate has a round cross section. I had an earlier problem with my bonnet lock . I measured the spring force when my lock began to open at 0.5 kg, I then compared that against an apparently original lock I had in my spares box- which required 1.5 kg initial opening force. When I looked for the difference between the two the older lock had a spring made of square section steel. This gives the spring's tensioning component much more cross section to store energy. Due to cost I can't see any aftermarket manufacturer making a lock spring out of square section coil - secure closing was probably the reason Triumph did so on the original. Edited April 30, 2017 by Mike C Quote Link to post Share on other sites
Sapphire72 Posted April 30, 2017 Report Share Posted April 30, 2017 (edited) Put some white chalk, or a dab of grease, or equivalent, on the tip of the bonnet bolt within that spring. Gently let the bonnet down to contact the receiving latch. Note where the 'substance' leaves its mark on the receiving latch. Slightly loosen the two bolts by the bonnet spring to adjust its position towards a proper mating with the receiver orifice. Tighten bolts when aimed right. Edited April 30, 2017 by Sapphire72 Quote Link to post Share on other sites
TR Paul Posted May 1, 2017 Author Report Share Posted May 1, 2017 Hi, Peter/Mike/Sapphire, many thanks for these tips. The bonnet isn't opening uncontrollably on humps, only if (sometimes) the opening mechanism has been activated immediately prior to, or whilst driving over said hump. Using your advice, I'll investigate this situation today... Best wishes, Paul. Quote Link to post Share on other sites
flinty Posted May 1, 2017 Report Share Posted May 1, 2017 Paul, Try a smear of silicone grease on the bonnet buffers, On mine when the bonnet got warm and expanded it then was gripped by the rubber bonnet buffers and would not open until I drove over humps or rough ground. Steve. Quote Link to post Share on other sites
TR Paul Posted May 1, 2017 Author Report Share Posted May 1, 2017 Interesting... thanks Steve. I've just read on earlier thread that the height of the buffers can affect this situation too, so well worth investigating. Cheers, Paul. Quote Link to post Share on other sites
RogerH Posted May 1, 2017 Report Share Posted May 1, 2017 Hi Paul, I cover the top of the bulkhead bracket with masking tape and put a smear of grease on the bonnet plunger. Gently lower the bonnet onto the masking tape. Lift bonnet and see how well aligned things are. Roger Quote Link to post Share on other sites
mike3739 Posted May 1, 2017 Report Share Posted May 1, 2017 Hi Paul, I cover the top of the bulkhead bracket with masking tape and put a smear of grease on the bonnet plunger. Gently lower the bonnet onto the masking tape. Lift bonnet and see how well aligned things are. Roger Spot on Roger Cheers Mike Quote Link to post Share on other sites
bob-menhennett Posted May 2, 2017 Report Share Posted May 2, 2017 I've used Blutack for the same purpose. A perfect indentation and can be re-used again until the optimum position is reached. Bob Quote Link to post Share on other sites
TR Paul Posted May 3, 2017 Author Report Share Posted May 3, 2017 (edited) Hi, I've checked the alignment (using Rogers' masking tape method), and it all seemed fairly straight (FYI- it looked like the catch spring's made from round section steel). I then (using advice from an earlier post on the forum) lowered the buffers at the rear edge of the bonnet opening, & this seems to have done the trick (fingers crossed!). Many thanks for all your guidance in this direction... Cheers, Paul. Edited May 3, 2017 by TR Paul Quote Link to post Share on other sites
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