MGB bonnet catch - an alternative solution
V8NOTE438 Malcolm Venables reported a dangerous experience he
had suffered with his bonnet catch failing which allowed the
bonnet to blow up onto his screen. He describes how it happened
and recommended the bonnet catch should be checked carefully
as a service item. Here Jon Moulds explains how he has developed
a solution. (May 12)
A number of reports recently have described how MGBs have had
bonnets fly open at speed. The cause has been due, in part,
to the original type of safety catch failing to do the job it
was designed for. Having experienced this first hand when a
bonnet opens at speed, often several things happen: the bonnet
prop is ripped from its mountings, the bonnet hinges will bend
along with the rear section of the bonnet frame, the front of
the bonnet will wrap itself around the roof, damaging it beyond
economic repair, the roof itself may become dented from the
force of the impact and the windscreen can shatter.
The whole event will take place in a split second and the first
a driver will be aware of the situation is when an incredibly
loud bang occurs as the bonnet hits the roof, not to mention
the driver's view of the road ahead will be completely blocked
whilst attempting to get the vehicle to the side of the road:
a potentially life threatening situation.
What can we do to ensure this dangerous situation doesn't occur?
The first essential check is to ensure both the bonnet catch
and safety catch are properly adjusted. *Note* Whilst working
in this area, the bonnet release catch and cable could probably
do with greasing as they are often forgotten about until at
the crucial moment the cable goes "ping".
As an extra cautionary measure, some owners elect to fit a bonnet
strap. This is a fine solution so long as you don't mind non-original
features, but what can an owner who is both safety conscious,
yet would prefer their car continued to appear standard from
the outside do? Well, for those with originality concerns or
a rubber bumper model that cannot easily be fitted with a bonnet
strap, there is now an alternative solution in the form of a
second safety catch.
The solution I came up with was to utilise a "break away
cable" kit as you can find fitted to caravans or boat trailers
and a small U clamp. The kit adapted to the MGB bonnet comprises
of a simple sprung clip, like a carabiner, at one end which
should be attached to the existing U bracket on the slam panel
of the car. The other end of the suitably shortened cable is
secured to the original safety catch with a clamp.
installation is quite straight forward as follows:
> Remove the 3 bolts holding the safety catch to the
> Drill two small holes through the handle of the
> Shorten the cable to around 8 inches in length.
> Pass the cable through both of your pre-drilled
holes and loosely fit the clamp.
> Reattach the safety catch to the car.
> Adjust the length of the cable to suit the car.
You should aim to keep the cable as short as possible whilst
giving enough free play so you have space to reach in and operate
the sprung arm of the carabiner.
> Tighten the clamp up and trim off the excess cord.
The plus points of this modification are it allows the car to
maintain a standard outward appearance but gives a third layer
of security in case the bonnet catch and original safety catch
fail. The only down side is that you will need to release the
sprung clip of the carabiner every time you open the bonnet,
but arguably this is no more effort than having a leather type
bonnet strap fitted?
Suitable breakaway cable kits can be sourced from either your
local automotive supplier, your local caravan and camping supplier
or even your local chandlery. Suitable U clamps can often be
sourced from the same suppliers or even from within the lighting
section of a DIY home improvement store.
See our illustrated A4L PDF note online for better copies of
these photos. More