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TR2/3/3A TR3 Oil Pump

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Tinkerman

Tinkerman

Darth Vader
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Regarding the oil pump the shop manual states "no adjustments are likely to be required until approximatly 200,000 miles have been covered". Is this reasonable in ya'lls experience? I have throughly cleaned it and I have a new filter assembly, can I just button it back up and call it a day?

Thanks, Tinkerman
 
Page 38 of Haynes Manual says it all. You need to measure the clearance with a feeler gauge between the bottom of the lobes and the bottom of the housing. It should be about 0.003" to 0.005". If it's more than this, your oil pressure will be low. If it's more you will need to lap the housing or the bottom plate on a flat surface such as a piece of plate glass with sandpaper on it. Look for uneven wear on the lobes where they mesh. If the long steel shaft is worn, the pump will cock and cause this wear. If the long steel shaft is worn, it may have been made from soft steel. Check the bushing that guides it too. If the shaft is not worn, it is probabaly made from hardened steel with a hardness of 60-62 on the Rockwell "C" scale. If the lobed part is pinned to this shaft, it's an older and probably an original style pump. Most of the repro pumps since about 1985 don't have this cross pin to secure the lobed part to the shaft. They use straight knurling on a soft steel shaft instead. The soft shaft wears. The lobes get worn. It has been reported many times that the knurling can let the lobed part slip on the shaft and you lose all oil pressure without any warning. The shaft is turning but the lobed part is slipping on the shaft. Mine that I bought in England in 1987 was like tais and I modified it to put a hard shaft and a cross pin in it. I've driven 94,000 miles with no trouble.

Don Elliott, Original Owner, 1958 TR3A

https://www.triumphest2006.com/images/clubcars/30donelliott'str3.jpg
(Photo taken at VTR 2001)

If you have pinned shaft pump. Check it and re-use it if it's good as per Haynes.
 
Hi Tinkerman,

Don has given you lots of good guidance! I can only add a little.

Yes, the original oil pumps were quite well made, simple in design, pretty easily servicable and seldom give any trouble. In fact, some turn out too high pressure, so there is a relief valve on the filter head of most 4-cyl. TRs that can be used to reduce it to a level that won't blow out seals. This adjustment can also be used to increase pressure, if an older pump is not producing quite as much pressure as it did new. Check the manual for specs and procedures.

And, as Don mentions, if you end up installing any new parts there are a few things to watch out for:

The drive shaft for the oil pump (and distributor) is another possible area of concern. If fitting a new one, a hardened type is more difficult to find but recommended if at all possible. Also look closely at the end where the shaft fits into the oil pump. If the tang on it's end is very sharply machined, or if it has any sharp burrs along the edge these can cause rapid wear, binding or even breakage if too tight a fit into the slot on the oil pump. The slot on a new oil pump might also be too sharply machined or have burrs. These are possibilities with new parts, but unlikely on used ones that have years of service and "worn in" together. If using new parts, in some cases it's a good idea to round the edges just slightly, first with a file then with some fine wet/dry sandpaper or a stone. Clean it all very well after this sort of work, so that no grit ever gets into the engine.

There is also a process for setting the end play of the pump/dizzy drive shaft, by shimming the dizzy pedestal. The seals that go under that pedestal are not just seals, they are also shims. That's in the manual, too. Check it out. Usually new parts are a good fit, but too tight or too loose can cause problems, so it's just good practice to check.

I also agree with Don about pinning the lobed part to the shaft, if that's not already done. That has been a problem with some of the replacement pumps in recent years. Also, even if there is a pin in it, take a close look at it. Some aren't very tight and can be pushed out quite easily (i.e., the original pins took significant force to push out). If it's loose fitting, a fix I've seen discussed - but not had to do personally - is to remove the loose fitting pin, tap some threads in the hole and then install a socket-headed set screw with some Locktite, to keep everything secure.

/ubbthreads/images/graemlins/cheers.gif
 
Thanks Don and Alan. I'm happy to say that the oil pump is within 3 to 4 thousnds end float and the rotor is firmly pinned to the hardened shaft Unlike much of the rest of the car which seems to epitomize Murphys law.
Thanks for taking the time to help me out, ya gotta love the forum.
Cheers, Tinkerman
 
Hi Tinkerman yes always sound advice from those guys. In short, an oil pump has an easily life (as long as it has oil) and it sounds like yours did. Throw it back in and call it day. It is probably better than some of the stuff you buy new even with the pin.
Sp53
 
The new rotor on the pump shaft is made using powder metallurgy (much like molding the powder in a mold to get the final shape without any machining) whereas the original ones were machined out of a piece of steel. And the repro ones look and feel "softer", so I think they will score more readily if you get a small piece of grit, sand or a metal sliver in the pump.
 
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