'68 1800 bonnet release mechanism

Alan Beckett · Mar 5th, 2006, 19:31

Hi, I am rebuilding a '68 1800S that someone took apart years ago and never got round to putting back together. I am currently struggling with the bonnet mechanism. When lowering the bonnet, the retaining bar catches only just connect with the lugs on the bonnet. The shortest of the two prongs on the catch is at the top which seems odd, but the bar is in the body the correct way round.

When operating the lever, instead of pulling the bonnet tight, the bar flexes and pulls down while the catches hardly move at all. Consequently the bonnet does not shut. I had recently taken the lever apart to clean off all the old paint and crap that was on it (nice chrome underneath) and I think I have put it back together correctly, but I have my doubts.

Should the bar move the catch backwards (ie towards the boot) or forwards (to the radiator) to close the bonnet?

Does anyone have any suggestions as to what might be wrong or have any photos of a mechanism that does work that I can compare with my own defective unit?

Andrew (UK) · Mar 5th, 2006, 22:42

I don't actually know which way it rotates, but I would guess that it must be down and towards the front. I don't believe that there would be enough give for anything else to happen. See attached picture for a shot of mine soon after I got the car.

mike gilbert · Mar 6th, 2006, 08:05

The bar simply pulls the prongs down and the shorter - top - ones pull down over the bonnet brackets to close it. Are you sure the brackets are in the right place? They are adjustable with captive nuts and shims. If they aren't in the right place and at the right height the catches will not close over them and simply pull against them, flexing both bonnet and bar. That is your problem I'm sure. Loosen the screws holding the brackets to move them slightly and try them in different postions. Don't forget your bonnet rubber either, or the two bungs on the bulkhead that stop the bonnet going down too far.
Mike

Alan Beckett · Mar 7th, 2006, 23:06

Mike / Andrew,

Many thanks. I'll try the adjustment on the retaining bar this week. The other problem is that the handle inside the cab flexes the steelwork it is bolted to when trying to lock the bonnet down. The spring on the level provides a huge amount of tension. Is this normal, or have I reassembled it the wrong way?

mike gilbert · Mar 8th, 2006, 07:53

I mean the brackets on the BONNET not on the bar. Loosen the screws to give them some movement (but be carefull of the shims falling out) and close the bonnet to allow them to be pulled into correct alignment. It is because they are not in the right place you are getting the flexing - something has to give if your pulling on several bits of metal that don't fit right.
Mike

Mar 5th, 2006, 19:31	#1
Alan Beckett Member Last Online: Apr 1st, 2014 23:55 Join Date: Nov 2004 Location: Stockport	'68 1800 bonnet release mechanism Hi, I am rebuilding a '68 1800S that someone took apart years ago and never got round to putting back together. I am currently struggling with the bonnet mechanism. When lowering the bonnet, the retaining bar catches only just connect with the lugs on the bonnet. The shortest of the two prongs on the catch is at the top which seems odd, but the bar is in the body the correct way round. When operating the lever, instead of pulling the bonnet tight, the bar flexes and pulls down while the catches hardly move at all. Consequently the bonnet does not shut. I had recently taken the lever apart to clean off all the old paint and crap that was on it (nice chrome underneath) and I think I have put it back together correctly, but I have my doubts. Should the bar move the catch backwards (ie towards the boot) or forwards (to the radiator) to close the bonnet? Does anyone have any suggestions as to what might be wrong or have any photos of a mechanism that does work that I can compare with my own defective unit?

Mar 6th, 2006, 08:05	#3
mike gilbert Master Member Last Online: Yesterday 12:52 Join Date: Dec 2003 Location: Peterborough View Photos By: mike gilbert	The bar simply pulls the prongs down and the shorter - top - ones pull down over the bonnet brackets to close it. Are you sure the brackets are in the right place? They are adjustable with captive nuts and shims. If they aren't in the right place and at the right height the catches will not close over them and simply pull against them, flexing both bonnet and bar. That is your problem I'm sure. Loosen the screws holding the brackets to move them slightly and try them in different postions. Don't forget your bonnet rubber either, or the two bungs on the bulkhead that stop the bonnet going down too far. Mike

Mar 7th, 2006, 23:06	#4
Alan Beckett Member Last Online: Apr 1st, 2014 23:55 Join Date: Nov 2004 Location: Stockport	Mike / Andrew, Many thanks. I'll try the adjustment on the retaining bar this week. The other problem is that the handle inside the cab flexes the steelwork it is bolted to when trying to lock the bonnet down. The spring on the level provides a huge amount of tension. Is this normal, or have I reassembled it the wrong way?

Mar 8th, 2006, 07:53	#5
mike gilbert Master Member Last Online: Yesterday 12:52 Join Date: Dec 2003 Location: Peterborough View Photos By: mike gilbert	I mean the brackets on the BONNET not on the bar. Loosen the screws to give them some movement (but be carefull of the shims falling out) and close the bonnet to allow them to be pulled into correct alignment. It is because they are not in the right place you are getting the flexing - something has to give if your pulling on several bits of metal that don't fit right. Mike

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)