In <199605162022.VAA08924@wolfie.guardian.co.uk>, Ad Design wrote:
>I've been experiencing a knocking noise from my rear axle. It occurs
>during gear changes and sudden acceleration and deacceleration. When I
>remove one of my rear wire spoked wire wheels and wipe any grease away it
>disappears for a while but soon returns.
The splines are meant to be greased, and the knockoffs should be
whacked on fairly tightly.
>This leads me to suspect the splines have worn. How do I know if my
>splines have worn? Is there some sort of measurement I can carry out?
Jack up the rear end. Loosen (but do not remove) the knockoff.
Insure that emergency brake is set. Rotate the wheel by hand. There
should be only a little slop (something like 1/8" at the outer edge of
the tyre). If there is more, then the splines are indeed worn. This
can be felt inside the wheel by cleaning out the crud and noting a
sort of ridge in the splines. Paradoxically, the splines get sharper,
not duller, when they are worn (a little thought is sufficient to
figure this out). The splines wear on both the wheels and the hubs.
In general, worn splines require replacement of both.
>I presume the noise is from a spline jumping a tooth or two.
Ooooh, I hope not. If you are in that state, your car will soon go
I'd also check your driveline for bad u-joints and the dreaded
rear-end clunk. U-joints are inexpensively replaced, and rear-end
clunk can be lived with for some time. To make these checks: (a)
U-joints--grab the driveshaft and check for any torsional looseness at
either front or rear u-joint flange. If you feel any slop at all,
it's too much. (b) Clunk. Set the emergency brake. Put the tranny
in neutral. Check for torsional slop at the rear end input flange.
There is supposed to be some (like 1/8" at the outer radius of the
flange). More would indicate worn thrust washers and/or spider gears
in the diffie itself. Sometimes fixable, sometimes not, but not a
disaster, it'll keep soldiering on for a while.
A. B. Bonds