Hood Prop Rod Replacement with Gas Cylinder
How many times have you been frustrated while opening the hood (bonnet) of your car - trying to hold up the
hood while releasing the prop rod from it's rubber holder then trying to place the prop rod in its holder on the
This may be the answer for you.
With thanks to Alan Bromfield
“One of the irritating design issues that I have with the 6-cylinder Healeys is the bonnet prop location and
On the AH100 it is nicely arranged so that the bonnet prop is hinged in the engine compartment and hooks
into the raised lid. This works well. Unfortunately with the 6-cylinder cars this arrangement is inverted. The
prop rod is hinged on the bonnet and clipped into a rubber retainer to the rear, near the hinges. The result is
that after releasing the two side safety latches (both hands) and lifting the bonnet you have to stretch down
the length of the engine bay to grab the prop rod whilst holding the bonnet aloft with the other hand.
Stowing the rod is worse as clipping it into the rubber can take a bit of effort.
I looked into the possibility of setting up the prop rod hinging it from the underside of the shroud and
propping it into the bonnet, however stowage would still be one-handed to the rear of the engine compartment
whilst holding the bonnet aloft with the other.
I decided to use SD01-200 'Variable force gas struts' instead which removes the need for the prop rod.
bootlid. The length when open placed the lower end on (or close to) the shroud support brackets, and the
stroke length allowed the bonnet to close without 'bottoming' out on the strut shoulders.
The struts are delivered gassed up to maximum strength/pressure and can be bled off to the required
strength after fitting. Stand off brackets were made to pivot the lower ends to the inside of the shroud
gutter. The upper ends use the hinge front bolt location. As a result the angle of the strut is almost 90degs
to the bonnet when open but flattens until parallel with the bonnet when closed. This results in the bonnet
needing to be lifted from the bottom of the stroke until about a third of the way up after which the springs
take over and lift it to the top. I fitted the struts one at a time and bled each one until it was barely strong
enough to hold the bonnet open. Then with both fitted the bonnet the combined spring pressure held the
bonnet securely at the top of the stroke with an acceptable level of force. Too much pressure would risk
distorting the bonnet as it is pulled down against the lift.
Now I open the bonnet the first 30% of the lift and from there the bonnet self opens to the top. Closing can
be a one handed affair as the bonnet latches perfectly if dropped under its own weight the last 10 inches or