Joe - Is it a new pump ? Zero miles on it ? Or is it an older one that you
put back in ?
Does this pump have a cross pin to secure the rotor lobes at the bottom to
the shaft ?
There were and still are TR pump shafts that were made with a soft central
mild-steel shaft with straight knurling to secuure this lower lobed part to
the shaft. These pumps have been known to slip at this knurling.and your
pressure goes quickly towards zero oil pressure.
The one I bought in London in 1987 was like this. It worked fine for 35,000
miles or so, Then the pressure started to drop. By this time, I had heard
about some disaster stories with these knurled pumps. I took mine out and
because the shaft was a knurled shaft, they make them out of mild steel to
get about 0.001" depth of knurling. Then they press the lower part of the
pump onto the knurled shaft - to "secure" it. The central steel shafts are
not hardened so they wear. Also with wear on the mild-steel shaft they
start to rotate "off-axis" and you get funny wear on the lobes. My mild
steel shaft had worn itself down about 0.010" and the end clearance had
changed. Worse than that, the steel grit that had worn off the outside
diameter of the mild-steel pump shaft and the lobes was imbedded in the
babbitt of all my big end and main bearing shells. I had to have the crank
reground and since I couldn't source a new pump with a cross-pin and hard
steel shaft, I bought a 12" length of Rockwell C60-62 case hardened shafting
for about $12.00 and made a new shaft with my hand grinder, cround through
the case hardening where I wanted the cross pin, re-assembled it and
cross-drilled it and pit in a new securing cross pin. At this time, I also
put the end play within spec.
I've drive another 50,000 miles of high-speed touring (794 miles home from
TRA in one day) with this pump and hardened steel shaft and the oil pressure
is still where it was when I put it in.
If this is your case Joe, I suggest you try to find an oil pump with a cross
shaft instead of knurling.
Don Elliott, 1958 TR3A, Montreal
----- Original Message -----
From: <N197TR4@cs.com>
To: <fot@autox.team.net>
Sent: Tuesday, August 24, 2004 11:18 PM
Subject: Low Oil Pressure-TR3A
> I'd like to think I could with Jerry VV on this one, 'cause it is the
easiest
> fix for me and inquiring listee.
>
> Scored End Plate on Oil Pump.......
>
> My cam bearings, rocker arms, etc. are all in spec. and I am getting 30#s
at
> idle after warmup.
>
> I dont remember resurfacing the end plate like I did on the race car.
>
> Joe (A)
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