Adjusting the bonnet (hood) Dzus fittings etc.

[Ian Vincent]

I spent a substantial part of yesterday afternoon fitting the Dzus fasteners for to the bonnet and then adjusting them. The fitting was pretty straightforward using the method that Stan posted here recently, apart from the final step of crushing the dished washers to retain them in place. I have a pair of long throat G clamps that had enough reach but I needed three pairs of hands to hold everything in place to avoid chipping the paintwork. I'd be interested to know if there is an easier method.

 

Anyway having got them fitted, I then spent an age adjusting the connecting fitting on the inner wing. Getting the right horizontal position was easy, I eyeballed the right spot prior to fitting the Dzuses and then took measurements from the inner face of the wing, but getting the right amount of packing under the bracket so that the Dzus fittings would connect was a hassle.

 

And when I'd finished the spring plunger on the bonnet lift has enough strength to flex the bonnet up by nearly 1/4 inch meaning that although everything is perfectly aligned at the edges there is a misalignment in the centre.

 

Is this normal? or is there a simple fix?

 

Rgds Ian

 

Don't ask me why this post has appeared twice

Edited July 12, 2014 by Ian Vincent

[Rodbr]

Hi ian,

Not sure if you are using original spring but I had the same issue. I ended up shortening the spring to reduce the uplift pressure, I still have a little rise just at the spring lift and centre but it was the best compromise i.e. enough to get the fingers under to open the safety latch but less to push up. I am not sure about whether or not this was the original one but it was over strong for the job. Perhaps over time the bonnet does tend to arch in the centre but a lot I have seen like this and it doesn't bother me that much.

FWIW I also found the reproduction packing shims were rubbish and made my own from leather, over time they get wet and distort and look a mess.

 

This was the best I could achieve but only from certain angles can you just see the catch section. Reasonably happy with the result and unless you want to try bending the bonnet up at the outside edges which may cause the outer catches out of line. I think I took about 2" inches out of the spring length.

Edited July 12, 2014 by Rodbr

[Lebro]

Three choices:

Leave it as it is

Weaken the "push up" spring by grinding off some of the coils

Flatten out the natural shape of the front of the bonnet, so that the spring pushes it back up to the correct position.

 

Mine looks OK when shut, so I'm guessing that without the spring it would be low in the centre.

 

Bob.

[Guest]

What Bob said.

 

I put some alloy under the bracket. And there's a very thin layer of rubber between the body and the alloy.

 

Menno

 

[Don Elliott]

I recently had the front end of my 1958 TR3A repaired after a front-end collision. There was a difference with the replacement valance and the bonnet was about 3/8" too high for about 1/3 the width of the bonnet so I removed the long bolts along the top front of the valance. Then I took my pneumatic die grinder with a 1.4" diameter cylindrical cutter and opened up the holes to a vertical slot shape. The cutter was long enough to go all the way through the square aluminium tube and this made the far holes also slotted. Then I put the nuts and bolts back in and secured them one after the other.

 

The photo shows the vertical gap before I repaired it to be flush

 

Now the gap is not only even from side to side between the valance and the bonnet, but the 3/8" difference in height is gone and they now match perfectly.

Edited July 12, 2014 by Don Elliott

[Ian Vincent]

I made my packing shims from thick rubber sheet which I will replace with something more substantial in due course.

 

Menno how do you manage to avoid the paint chipping off your brackets? The paint has chipped around the edges of mine after only a few uses and I suspect that even when I touch them up, they will chip again because there is so much flex in the bonnet, the Dzus doesn't necessarily go through the centre of the bracket every time.

 

Rgds Ian

[Don Elliott]

Ian - Before you secure the Dzus bases, leave the bolts about one turn loos. Then close the bonnet and lock the Dzus down with the "T" key. This will centralise where the Dzus bases should really be. Then lift the bonnet and tighten down the 4 bolts for the Dzus fastener bases. They should now be easy to lock down for the next several years with no forcing with the "T" handle.