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RE: TR3A oil pump drive shaft

To: <triumphs@autox.team.net>
Subject: RE: TR3A oil pump drive shaft
From: "Randall Young" <Ryoung@navcomtech.com>
Date: Sun, 13 Jun 2004 07:05:03 -0700
> I am now hearing a rattle/fluttering type noise which I beleive may be
> attributable to the oil pump drive shaft (?key/bushing/shaft?).
> It is not evident at
> all engine speeds. I would not say that it is loud, but I hear it.

Ed, why do you think this is a worn shaft/bushing rather than the worn rod
bearings that would normally accompany low oil pressure (and also rattle
under some conditions) ?  Worn rod, main and cam bearings are the usual
causes of low oil pressure (and are the main reasons that low oil pressure
is a problem).

Since low oil pressure may also indicate a problem with the pump, I would
recommend dropping the pan to investigate.  Fortunately, that's a relatively
simple operation on a TR3A.  You don't have to remove the apron, drain the
radiator or even take the motor mounts loose.  Just drain the sump, remove
most of the pan bolts (leave a few to support the pan during the next
operation), loosen and swing away the braces for the road draft tube and
clutch slave, remove the remainder of the bolts and gently rap the pan with
a rubber mallet to loosen it.

With the pan off, you can remove & inspect the oil pump for wear, broken
rotors, etc.  Specs are in the book, I don't recall them offhand.  Rods &
mains can be measured with Plasti-gage.  And with the oil pump out of the
way, you can wiggle it's drive shaft and see if you think that is the
problem.

> The questions ...
> (1) Does replacing/repairing the shaft, etc require removal of
> the oil pump
> assembly (dropping the sump), or can the work be done from the
> top through the
> dizzie. The shaft in question apparently drives both via the
> camshaft. Any
> recommendation form those who've been there.

I've not been there, my zillion-mile engine block still has it's original
bushing (and since the bushing is softer, it's more likely to wear than the
shaft).  The shaft itself comes out easily through the top, once you remove
the distributor pedestal and drive gear.  The shaft fits into the drive gear
with a slip fit and a Woodruff key, most likely it will come out with the
gear.  If not, reach into the hole with your fingers or chain nose pliers,
and pull it out.  Reassembly from the top can be a bit tricky though, as the
gear has to turn as it fits into place, and it's important that the right
tooth is engaged with the camshaft.

> (2) Is the Moss replacement shaft of good quality. Is there
> another supplier.
> VB does not list it. Haven't called TRF.

No help there, I'm afraid.  Last I heard, the bushing was not available
anywhere.

> (3) Do my assumptions (as to the source of the rattle/flutter)
> appear to be correct?

I'd say it's unlikely ... but anything is possible.  These engines always
amaze me at how well they run in advanced states of wear.

Randall





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