Waterpumps

[Daryl Gatenby <Daryl.Gatenby@domain.elided>]

Hi Ian,

The last (and first) time a waterpump failed on me was about six months ago.
It chewed its gear teeth to bits and did the same to its opposing Jackshaft
gear teeth. It didn't seem to make any real noises until just prior (30
seconds) to failing. It made a grrrrr noise. Not very loud but definately
abnormal and almost certainly the final few turns of the W/P by the J/S
before they no longer had sufficient teeth to mesh effectively. The
temperature guage went from cold (when the noise started) to hot in double
quick time. If I had been less paranoid than I am about engine temperature
it could easily have been allowed to over heat. As it was the guage moved a
quarter higher than it normally would at operating temperature on a hot day.


Hardness testing of the failed part has shown that, in this case, it was not
in fact the gear teeth on the W/P shaft that were lacking in hardness. I had
5 W/P shafts tested along with the J/S and the failed W/P shaft. The five
known W/P shafts had all had travelled at least 100,000 KM's in their
respective engines and showed little wear. The shafts were hardness tested
and the hardness at the critical gear teeth points were similar to that of
the failed article. A Rockwell hardness test was used.  I can tell you lots
more about this subject if you like. 
  
I think the only way to find out if your waterpump/jackshaft gear teeth are
on the way out is to pull the pump and have a look.

I don't live nearby to you so cannot say where hardness testing could be
done.

As a matter of interest, what is causing you to doubt the integrity of your
W/P?


Regards

Daryl Gatenby

Hamilton
New Zealand

73 MOD