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Shock Tower Failure
I was going to give the Healey a rest this month , but something happened to
change my mind – like the front suspension falling off. Well that’s what it
felt like. The Healey has an upper wishbone which pivots on the shock absorber,
which itself is mounted on a suspension pillar. What happened was the top of the
suspension pillar decided it didn’t like the company it was keeping and peeled
open like a box lid away from the pillar, shock absorber, wishbone and all.
The result, of this as it affects the driver is considerable. I was
only going slowly at the time - around 60 mph on a dual carriage way - when the
car began to veer left. At first it didn’t appear to answer to the helm at
all. I’d reached the stage of merely wondering which hedge/tree/ditch we were
going to damage, then a few feet from the curb it did respond and thereafter it
was quite easy to guide it to a standstill without touching the brakes. I
thought that tire had deflated at that stage. However, on alighting from the
vehicle (as they say), it was immediately obvious that tires were not the reason
for this particular bit of drama, as the nearside front wheel was leaning
inwards at a very marked angle. On removing the wheel, it took me some time to
spot the actual cause as my search was directed immediately behind the wheel at
the swivel pin, which I felt sure must have broken. I was rather
amazed to discover the true reasons with the damper lodged up against the inner
wing panel.
I was resigned to have the Healey carted back to SE1 by the AA. (I’m a Relay
member and thankful for it) when simultaneously with the arrival of the yellow
van came Bob Smith and company, In an old blue Ferrari. It was Bob’s RS Panels
concern that I’d been on my way to visit and in fact I was by then only a
couple of miles away fron their Nuneaton workshops (this all took place on the
Bedworth by—pass). This prompted Bob to suggest that we limped the car back to
RS Panels where it could be welded up.
And thus it was; the shock absorber/wishbone is only held on by four bolts so it
was easy to remove, clean the area off, and refit the bent plate carefully and
weld it back into place. Bob Smith himself did the welding using a big arc
welder with a CO2 cooling jet. I asked why he used this instead of
his gas welding plant and he said that the electric arc heated up the metal
almost instantaneously which was an advantage in this sort of situation, where
the metal was quite thick the gas plant would get everything pretty hot before
welding could commence. It was quite a difficult job to do, crouched under the
wheel arch, but Bob did it beautifully. Alter the raised portions of the weld
were ground flat, the suspension was refitted, though Bob thought that to make
absolutely sure, a plate could be welded over the top of the suspension post.
overlapping it at the sides. We’re certainly going to do that, and
on both sides too, in the near future.
Well, you’ll be hearing more about Bob Smith when the
"specialist’ feature on his business appears jn the T & CC within the
next month or two. I certainly couldn’t have broken down at a better place.
However, that doesn’t alter the seriousness of what happened and I advise all
Healey owners to scrape the mud off their suspension uprights at the cop and
examine them for cracks. When I first got FOP 938D I did just that in fact, but
as I was really only looking for the rot in that area, I didn’t spot the
cracks that must already have been there because the front and rear edges of the
torn metal were "old". Rust was not Involved at all so stress is
obviously the cause; back in London I told Derek Spencer about it and learned
from him that this occurrence is not at all uncommon amongst Healeys, but that
as in my instance it usually happens at low speed. Not much comfort in this,
though so do have a look at your suspension., won’t you? Unless the cracking
is brought about merely by old age, perhaps a temporarily seized damper might
have been responsible for increasing the load on the upright for a period in the
past, or maybe it’s the legacy of accident damage—any other theories?
Submitted
by Terry 0’ Laughlin of West Allis, WI.
Reprinted from
"Thoroughbred and Classic Cars" October 1975.
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