Attention Sean, George, Jeff, and other Spitfire Owners:
Following was published in Tails and Trails (TTSCC Newsletter June 1994):
Tech Tip: Repairing Rear Axle Noise
As with most of the machinery in the club, age is
taking its toll. My wife, Linda, is blessed with owning a
later model with an effective age much less than its
actual years. As most Spitfire owners know, the rear
axle and suspension announces its presence with various
clunks, clatters, and bangs as it ages. Even though
hers is a 1979 model, an overhaul of the offending parts
was long overdue.
We undertook a combined project of repainting the
firewall, rebuilding the master and rear wheel cylinders,
and converting over to DOT 5 fluid (with which I am
very pleased on both the Spitfire and the Bugeye). As
we had the rear brakes apart anyway, it only made sense
to get into the suspension (why not, we already replaced
the upholstery).
Removing the axles and leaf spring is really quite
simple once you have the brakes apart. Just follow the
directions in the book, which I won't take space to
repeat here. What I do wish to share are several secrets
to the noise source and some innovative effective
repairs.
The source of the noises (plural being important) is
as follows from my best determination: First, the rubber
pad at the top center of the leaf spring was degraded
and dislodged. This allows about a quarter of an inch of
vertical play inside the spring bracket clamp which
secures the spring to the top of the diff. Also, there
were several missing pads between the leaves.
Rather than replace with outrageously priced dubious
quality catalog parts, just do this: Go to OSH and buy
a small scrap of quarter inch thick rubber and cut to
size (about 2" x 6") for the main pad. This will leave
some "ears" sticking out each side of the bracket atop
the spring. I think this is important to keep the pad
from displacing to one side or the other creating the
original problem all over again. For the little buttons
between the leaves, again use some of the same rubber
and carve to size and shape with a knife. It's real easy.
When reassembling, be sure to have the leaves clean of
grit and then relubricate properly.
The second source of noise is the bushings.
Replacing the radius rod bushings is very easy. The
rear radius rod bushings seemed noisiest. If you do not
want to undertake the whole project, try just tightening
the bolts through all the suspension bushings. Who
knows, you might stumble on an easy solution to a
Triumph problem!
As a side note, since the bolts were all worn, I
replaced them with some high-grade ones secured by
nylock nuts. Grease the bolts before installation.
Now, the leaf spring bushings were a different story.
I have a shortcut for getting the old ones out. Drill a
couple of holes from side to side through the rubber.
Use a bit diameter equal to the thickness of the rubber
plus the thickness of the outer metal bushing sleeve. Be
careful not to remove meaningful amounts of spring
material at the spring eye. But if you drill carefully,
you should have no problem cutting through the rubber
and the sleeve. After a couple of holes, the old bushing
will just push right out. Do not attempt to pound it out
without drilling these holes. You will damage your
spring and self esteem as an automotive technician.
Installation of the new bushing takes some care, as
the center metal sleeve is longer than the outer metal
sleeve. What this means is that if you just get out a big
hammer and pound, you will mess up the center sleeve
and the eye bolt will not go through properly when you
reassemble the suspension. Use a piece of steel about
1/4" x 2" x 6" on edge next to the center sleeve as a
place to gently pound on. This transfers the impact to
the outer sleeve where you want it. Move this tool
around as you pound so the bushing enters the eye as
straight as possible. This is all done with the spring
on the garage floor, not in the car.
When reinstalling the spring, upgrade all bolts and
use Locktite to secure the bolts in the diff. When I
bought the car, these bolts were backed out about 3/8".
No wonder it sagged in the back.
Here's another little noise abatement trick: Get some
1½" I.D. rubber hose from OSH. Cut four lengths to 1¼"
each. Slip two over each outer leaf spring end so that
the inner eye, which holds the bushing, is cushioned
above and below as it sits inside the outer spring eye.
You will find this 90¢ project not only makes your car
ride quieter, but also helps hike up the rear end
slightly. (models before '71 don't have outer this outer
leaf).
The third cause of noise was the inner axle bearings
and universal joints. This noise consisted of "mechanical
slack" and rumbling. Do this to solve your problem: Dial
1-910-884-1455 (Highpoint Imports) and ask for a set of
upgraded Spitfire axles, sit down, close your eyes, plug
your ears and give them your credit card number.
These will set you back $220 per side. But let me tell
you, this was the best $440 I spent on the car.
These axles arrive with all new u-joints, trunnion
bushings, seals, and bearings. The inner flanges, outer
uprights, and brake backing plates are also part of the
assembly. Each set is complete, cleaned, painted and
ready to install. The real beauty of these is in the inner
bearing modification. Stock axles run the inner needle
bearing on the shaft. Highpoint modifies the trunnion
and shaft to accept a larger bearing that runs in its own
inner and outer races, the way it should have been
designed originally. The old axles can't take new stock
bearings because the shaft is usually damaged when the
inner bearing fails, since the shaft is the inner race.
I went to great lengths finding the best solution,
since the right side inner bearing failed during the 1993
Moss Festival Wine Country Rallye last year. (Moss did
not have the part. But a garage in Buellton did, and
fixed me up temporarily. Yes, in Buellton! And thanks
to Skip Kelsy of Shadetree Motors, 510-846-1309, a
British parts distributor from Pleasanton, who drove me
all around Buellton looking for the parts).
For your interest, certain components did not
contribute to the noise problem. I removed and examined
the differential output shaft bearings. They were fine.
I reinstalled with new gaskets. No problem. The
differential mount bushings were examined. They were
still sound. They may have already been replaced when
the differential was changed by the last owner. Also,
the shocks were of recent installation, so I eliminated
them from consideration. Check your shocks, though.
They are to be of gas charged variety that have upward
static thrust of 35 pounds per side. This will raise a
sagging rear end a bit. Some of the cheap replacements
are not gas charged. And finally, check your drive
shaft u-joints. I replaced the rear one some time ago as
a separate project. It was dry and failing even though
it made no noise and I could not manually displace the
yokes. It had become suspect when grease would not
come out all four cups when it was lubed. If in doubt,
yank it out.
Even after several thousand miles of road testing,
there is no noise whatsoever from the rear suspension.
Even on rough surfaces. The car also rides higher,
corners better and looks better without all the squat. It
was well worth the time and money. Next article I can
detail the DOT 5 conversion.
Brian Neuschwander 408-356-9304 408-374-8766
June 1994
ps--now a year and a half later, all is well. Highly suggest you do it all.
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