Flying bonnet

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JPL1
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Flying bonnet

Post by JPL1 » Thu May 30, 2019 8:36 pm

Hi All,
Failed my MOT today (1980 GTC auto) - lower front trunnion wishbone bushes (looks like an easy fit), tyres (inward bulges, date-marked 2004, and one rear rubbing on inner wing (turns out previous owbpner has squeezed 205s onto rims intended for 195s!) and a bonnet catch that keeps releasing over pumps. It seems that the catch is not coping with the body flex. Has anyone else had this issue, and if so, is there a fix? I have tried a few adjustments to the catch rod on the bonnet. Tomorrow I will try to dismantle, lubricate and free up the catch mechanism, but it all looks really clean and operates smoothly. Amy ideas appreciated.


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Rev Light
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Post by Rev Light » Thu May 30, 2019 9:27 pm

Mine popped open at 60 miles an hour last year. Plenty of damage to the bonnet. Safety catch didn't. The bonnet release had started to bind and had not properly returned. Take it from me, it is something to try and avoid.

Steve


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peter freeman
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Flying bonnet

Post by peter freeman » Thu May 30, 2019 9:38 pm

Is the spring on the bonnet "male" strong enough to hold it in place



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Post by RonH » Thu May 30, 2019 10:06 pm

JPL1 wrote:
Thu May 30, 2019 8:36 pm
Hi All,
Failed my MOT today (1980 GTC auto) - lower front trunnion wishbone bushes (looks like an easy fit), tyres (inward bulges, date-marked 2004, and one rear rubbing on inner wing (turns out previous owbpner has squeezed 205s onto rims intended for 195s!) and a bonnet catch that keeps releasing over pumps. It seems that the catch is not coping with the body flex. Has anyone else had this issue, and if so, is there a fix? I have tried a few adjustments to the catch rod on the bonnet. Tomorrow I will try to dismantle, lubricate and free up the catch mechanism, but it all looks really clean and operates smoothly. Amy ideas appreciated.
Make sure the front catch plate is the correct way around. My bonnet catch on GTC 404 wasn’t. It’s has been like that for 4 years until it was spotted by Mike Simpson at the Oulton Park show. However, it never popped open thankfully.
Ron



JPL1
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Post by JPL1 » Fri May 31, 2019 11:49 am

Thanks, Peter Freeman. That is something I am going to investigate, along with making sure the release cable is not stopping the catch from fully closing (though I would have thought this would stretch over time rather than contract, so this would only be the case if it was poorly set up during the previous restoration (which I have to say looks supremely competent)).


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Post by b.c.flat hat » Fri May 31, 2019 12:34 pm

There's a little "widget" on the end of the outer cable underneath the catch panel in the engine bay. It fits in a slotted bracket to provide its positive stop. My had half popped out and the bonnet opened to the safety catch at 90 on Ty Croes!
Here's hoping that's all that's amiss.



JPL1
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Post by JPL1 » Fri May 31, 2019 6:19 pm

OK. I have had the whole thing apart this afternoon. I noticed that the release lever cable grip was upside down and was snagging on the front panel lip. However, this did not solve the problem. The release cable was also a bit tight, so I gave it some slack, but this did not fix it. The lock was simple not closing far enough to hold on to the "male" (as Peter Freeman so brilliantly described it, considering its profile!). When off the car, is fully closes. When in place and tightened up, it does not. It seems to be deforming when tightened up and the sliding mechanism will not fully close (spring has plenty of pull in it). So I have bitten the bullet and ordered a new one from Graham Walker. In the meantime, I am considering making up a steel plate to fit under the front panel bonnet resting ledge that will hold the lock, the release cable "abutment" and the return spring bracket. There just seems to be too much give in the area to keep it all rigid over bumps. If it comes to pass, I will share a pic!


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Post by ard126k » Fri May 31, 2019 8:49 pm

Did you notice that the 'male' member is adjustable by turning once its locknut is loosened?

Alex.


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JPL1
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Post by JPL1 » Sun Jun 09, 2019 9:07 am

So, full marks go to RonH. The latch was in fact on upside down! This did not become obvious until the new one arrived with a strange elongated dome underneath it to contain the male member. This was missing from mine, enabling someone to fit it upside down! I have put the new one on and will recondition the old as a spare. Thanks to all for your input. MOT now passed.


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JPL1
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Post by JPL1 » Sun Jun 09, 2019 9:10 am

Thanks Alex. Yes, I had spotted and have used this adjustment, along with anew set of rubber buffers, to get the bonnet sitting properly. Interestingly, the male member had also been I correctly reassembled, with the spring and top spring cup places above the lock nut, up agains the bonnet inner surface.


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