Bill,
The Clunk--could be a loose wheel, a loose damper, battery shifting in
its box, something loose in the boot (spare tire?), loose rear spring U
bolts, etc. Check around for things like that. A one-time clunk can be
difficult to find, but my guess is that it is nothing significant
although alarming.
The '76 cars' starters were the "pre-engaged" type. Earlier, "Bendix"
types worked by having the stationary inertia of the starter pinion cause
it to unscrew down the starter armature/shaft into engagment with the
ring gear when the starter motor began to turn. The motor starts very
quickly, hence the effect on the pinion. The pre-engaged type works by
having the solenoid (round box on top of the starter) force the starter
pinion into engagement with the ring gear before the starter begins to
turn, hence the pre-engagement. This is supposed to ensure that the
motor does not run without the pinion engaged, hence less grinding and
wear of the parts and no run-on once the car engine starts.
It could be, from what you describe, that the solenoid is sticking in
such a way that the gears have disengaged but the starter motor contacts
have not, hence the motor running on and the whirring sound. To test
this theory, you will have to disconnect battery and remove the starter.
Open the solenoid and check for free action. See that the contacts are
sound. Also, put a drop of WD40 or equiv on the starter shaft where the
pinion travels. If it's a sticking starter, that should cure any
mechanical causes.
Now it's also possible that the starter ran on because it received
electricity to cause it to turn. The starter is not supposed to turn
without being engaged, but it might have done. On the right side of the
engine, in the vicinity of the starter, check over the wiring harness
where it passes over the "chassis" member. It's not unknown for the
harness to chafe there, and for the starter to be energised by a cross
connection caused by worn insulation there. If the harness is OK on the
outside of the wrapping tape, it's probably OK. If you see wear on the
wrapping, look carefully for other troubles. When you're done, put a
protective piece of wire loom over the harness in this area. One of the
cars in our CT MG Club ran away this winter as a result of a cross
connection here.
Bob
On Sat, 17 Jun 2000 11:01:53 -0400 (EDT) Bill Saidel
<saidel@crab.rutgers.edu> writes:
> Learned bretheren,
> There is a part of game theory called the zero sum game.
> Colloquially,
> it boils down to "Win some, Lose some".
> Now that my replacement carb is fine, passed inspection, and I
> test
> traveled my 76B a few hundred mostly carefree miles, new sounds are
> cropping up. Some sound ominous. When you have time, might some of
> you
> experienced souls speculate?
>
> 1. The CLUNK. Occurance...shifting gear, going on the fly from
> engaged
> clutch to disengaged to [CLUNK] reengaged. This is probably not a
> u-joint
> as I replaced both u-joints last fall.
> It also seems to be coming distinctly from the right rear.
> This one has been present in some form since I first took possession
> of
> the car (May, '98). It seems a bit louder now (but then, I've had
> the
> battery cover off for one reason or another).
>
> 2. This one freaked me a bit. First occurance and so far, only
> occurance.
> I drove to the local Blockbuster to pick up a flick and all was fine
> sans
> Clunk of previous paragraph.
> Started engine to return home and almost immediately, it sounded
> like
> something was spinning in the tranny. It created a whine, a whistle,
> almost fanlike in its constancy but it was not a fan. It did not
> seem to
> interfere with the operation of the tranny on the drive home.
> Thirty
> minutes later I took it out to listen again and it was gone. No
> dash
> lights went on that shouldn't have.
>
> Could I have been fooled into thinking it was the
> transmission
> but it was really related to the starter motor? Of course I could
> theoretically, but I lack the experience to accurately evaluate this
> new
> noise. Seems to me I'd be better off if this noise signals the
> beginning
> of starter motor failure than tranny failure.
>
> As always, TIA,
>
> Bill Saidel
> Dept. of Biology
> Rutgers University
> 315 Penn Street
> Camden, NJ 08102-1411
> USA
>
> "Sacred cows make divine hamburgers."
>
>
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