Marc,
Several of us in our club had clanks coming from the differential, so
with informational assistance from Lawrie, Skip, Barney, Chicagoland MG
website, Moss Motors catalogue, and others too numerous to recall, we
undertook the task of changing the thrust washers, albeit with some
trepidation.
Surprise ! It's not half as intimidating as one's imagination makes
it. If you have more than 3/16 inch rotation of the flange at the rear
axle, put this service onto your list of things to do. Even if your car
has other problems, it has this one also if the axle has more than 60,000
miles on it.
Get a 296-210 gasket, two 267-140 thrust washers, two 267-130 thrust
washers, one 267-125 roll pin, and one 267-115 pin. Also get two
#120-700 oil seals and a quart of gear oil. All of us took this
opportunity to switch to synthetic.
Jack the car way up for workspace. We supported the car at the spring
mounts and let the axle hang down for better accessibility. Wirebrush
the top of the axle to get the area as clean as you can.
Follow the instructions you get; all are similar. All that we read
make a point of telling you not to knock in the #267-115 pinion pin "too
far". Good advice, but don't let it scare you. Tap it in about 5/16 of
an inch, which is far enough yet gives some safety clearance, turn the
gear, and the hole where the roll pin fit is exposed. Put a punch or a
skinny Philips screwdriver into the hole and twist out the pinion pin.
Pinion pin was a good fit and removed properly in one car. In two we
had to fight it out, twisting and pulling and growling at it. We could
have re-used two of the three, but they had .003-004 wear on them and we
had bought new. The car that has 200+M miles on it had the tightest pin,
with the least wear. That car also had the worst looking oil I've ever
seen. It didn't even drain out the hole w/o poking the sludge aside, and
the oil was warm from a 40 mile trip at the time.
Some say that you should put a cotter pin into the new roll pin.
Probably not a bad thing to do, though some in our group didn't,
believing that the roll pin doesn't have much incentive to become
dislodged.
Careful not to twist the brake line clamp where it bolts to top of
axle. Put a hand on the clamp as you turn the wrench to feel if it starts
to move.
You need one oil seal, but they are probably equally old, so buy two,
replace them both while the oil is drained.
#267-140 is a thin cheap phenolic washer. Not being an engineer, I
can't imagine why such a second-rate piece of plastic was used there,
when a bronze washer would have cost so little more. Perhaps this is a
washer designed by a cost accountant. You may find two, one or none in
your axle, as we did.
#267-130 could have been re-used on one car, was very worn and gouged
on another, and one was missing on the third car.
Two of us found that we could not bleed the rear brakes with the rear
of the car jacked up high. Once on the ground, it was easy.
Each car now has less than 1/8" free movement at the flange. Each is
smoother. Neither of the open-car owners could tell a difference in
noise, but the GT owner found a remarkable difference in cabin noise.
Bob
On Wed, 21 Sep 2005 12:00:24 -0400 Marc <smarc@smarc.net> writes:
> I know less about differentials then probably any other part of the
> car... which leaves much to be said!. Given that state of affairs,
> Marc
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