[ST] Sprag (starter) clutch failure

["Keith Tynan" <keith@xxxxxxxxxxxxxxx>]

Just to keep you all informed...

I had my sprag clutch 'fail' on me the other day - that's the third time
this year! (For those of you who don't know what sprags are, follow:
http://www.industria.co.uk/Commercial/gmn/clutches/press_fit_of_thin_walled_
rings.htm.)

Symptoms: Either the starter doesn't turn at all, and the console lights
dim - looking for all the world as if you've got a flat battery. OR The
starter motor turns (rapidly) without engaging with the engine.

Diagnosis: Dunno what to conclude on this. My (3 year old) battery is kept
on an Optimate charger most of the time, and it usually fires up with a
healthy turn of the motor. I've run a voltage check on it on a couple of
occasions, and all would appear to be well. On the occasions that the engine
doesn't turn, I would guess that the clutch is jamming in some way; as it
would be logical that the lights go out when the starter button is pressed
(I seem to recall that the starter relay shuts off the lights). A spinning
starter would seem to indicate that the sprags are failing to engage.

Treatment: Bump start your Precious - in 2nd gear, of course.

Cure: Touching wood, I read the workshop manual last night. Apparently,
replacing the sprag clutch is a crankcase-splitting exercise. Any similar
experiences or suggestions?

The first time, it wasn't a problem, as it happened at work (my office is at
the top of a 1-in-6 hill). Last time it was at home, which give me a
downhill gradient for the first attempt, then I'm at the bottom of a well.
This time it was more embarrassing, as it was at a petrol station (having
just filled up), on the flat, and after a hard day at the office. Luckily
Wolfram growled into life after the fourth hit with the defibrillators.

Regards,
- --
BRG
mailto:keith.tynan@xxxxxxxxxxxxx
http://myweb.tiscali.co.uk/keith.tynan
'00 BRG Sprint ST 'Wolfram'



     *   *   *   *   *   *   *   *   *   *   *   *   *   *   *   *   *   *   *
      The ST/RS Mailing list is sponsored by Jack Lilley Ltd.
          http://www.TriumphNet.com/st/lilley for more info
   http://www.TriumphNet.com/st for ST, RS and Mailing List info

=-=-=-= Next Message =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=