Oil pump rebuild

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Stephen, thank you very much for your input. You are very thorough with the procedure for a proper job and I appreciate the time you spent to post it.

It looks to be a copy/paste and some of it looks a little off the mark especially suggesting putting a conical oil pump to timing cover seal in a Mk111 which I thought all BUT the Mk111 had. (unless I read that wrong)

Your pump looks a little worse for wear but will most likely make usable pressure again with some time into it.

You wonder how an oil pump can wear when it pumps lubricant most of its life.
 
It looks to be a copy/paste and some of it looks a little off the mark especially suggesting putting a conical oil pump to timing cover seal in a Mk111 which I thought all BUT the Mk111 had. (unless I read that wrong)

Your pump looks a little worse for wear but will most likely make usable pressure again with some time into it.

You wonder how an oil pump can wear when it pumps lubricant most of its life.
Yes I asked myself that same question. I answered it myself while lapping with oil on Emery paper. I am going to do the best I can to tighten the clearances up. Other than the tires and handlebars, the oil pump is probably the most important part of the machine. It's kind of like a heart keeping the blood circulating. Thank you for your input Time Warp. Off the topic, on several posts I've seen "MrGreen". What does this mean?
 
It looks to be a copy/paste and some of it looks a little off the mark especially suggesting putting a conical oil pump to timing cover seal in a Mk111 which I thought all BUT the Mk111 had. (unless I read that wrong)

Your pump looks a little worse for wear but will most likely make usable pressure again with some time into it.

You wonder how an oil pump can wear when it pumps lubricant most of its life.
Maybe oil and carbon powder sliced thru
 
A general question about gear oil pump overhaul. I wonder if there is any benefit in chamfering the edge of the gears where they bear on the body and plates to reduce the wear ? Yes I know it would be time consuming to do, but those edges are normally pretty sharp.
 
I surfaced my oil pump once - based on the service manual. It was very straightforward and dramatically reduced wetsumping (which I didn't care about but that's a different subject). I did it because when I bought the bike in '06, I didn't trust anything about it and figured it was just a bit of "routine maintenance." But for those interested, it reduced wetsumping from draining the oil tank to the feed-pipe level in 4-5 days to a month. I had a '71 back in the day and when we actually rode these bikes instead of spending most of the time talking about how to "upgrade" them, none of us ever heard of "wetsumping." ;)


Side rant:

"Thanks for sharing that. It's nice to know what these machines are capable of in the right hands."

Frankly, my feeling about the "right hands" is people who do not see the need to "upgrade" things that were never broken to start with. Most of the "problems" with Nortons have been invented relatively recently by folks on the internet. ;)

Certainly, the age of the machines means there are items that need to be examined/renewed. Electrical wiring/any rubber parts is a good example. But IMO the only thing that really needs to be "improved" to use a Norton nowadays is a more effective front brake. Everything else can be "fixed" with the normal maintenance described in the manual or the replacement of parts due to normal wear.

Sure, there are convenience and appearance items that, depending on the individual, are very useful but that's a personal issue. For example, some folks think putting an E-start on a pre-MarkIII is sacrilege, others figure they are just doing what Norton had intended early in the Commando's production.
 
I read in the NOC newsletter that when lapping the faces down , the non driven spindle could become longer than the body and not allow the brass plate to be flush .

I have not seen the NOC newsletter but yes it is very easy to have the non driven spindle doing just that.
If the body is lapped to any degree the spindle length needs to be checked/addressed also.
 
Always been skeptical about lapping anything but the endplates, if you start taking material away from the body, not only do you have to account for the gear faces (which are hardened) and the spindle, but are you not also reducing capacity (as negligible as it may be)?
 
Always been skeptical about lapping anything but the endplates, if you start taking material away from the body, not only do you have to account for the gear faces (which are hardened) and the spindle, but are you not also reducing capacity (as negligible as it may be)?
In my mind ,gear faces should be touched up too to prevent scoring on the mating surfaces. The reduction in capacity, I would think, isn't an issue.
Edit: maybe those little spurs on the gear tooth edges are there by design to dig into the mating surfaces during run in to help seal and should not be lapped.
 
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BERT, one thing is important. On reassembly, make sure that the end plates do not protrude past the pump face, otherwise they may prevent the gasket sealing properly in the critical areas (which could lead to tears). Here you can see a good assembly with the plates very slightly below..


Oil pump rebuild
 
Thanks for the good advice. All 4 screws are free all the way thru with T.L.C. . I agree not a good idea unless neccessary to chase with a tap as brass damages so easily. How is the spindle separated from the front plate? I would like to lap the plate as well.View attachment 21981
I think that you will find that the pump screws are 2BA.
 
I surfaced my oil pump once - based on the service manual. It was very straightforward and dramatically reduced wetsumping (which I didn't care about but that's a different subject). I did it because when I bought the bike in '06, I didn't trust anything about it and figured it was just a bit of "routine maintenance." But for those interested, it reduced wetsumping from draining the oil tank to the feed-pipe level in 4-5 days to a month. I had a '71 back in the day and when we actually rode these bikes instead of spending most of the time talking about how to "upgrade" them, none of us ever heard of "wetsumping." ;)


Side rant:

"Thanks for sharing that. It's nice to know what these machines are capable of in the right hands."

Frankly, my feeling about the "right hands" is people who do not see the need to "upgrade" things that were never broken to start with. Most of the "problems" with Nortons have been invented relatively recently by folks on the internet. ;)

Certainly, the age of the machines means there are items that need to be examined/renewed. Electrical wiring/any rubber parts is a good example. But IMO the only thing that really needs to be "improved" to use a Norton nowadays is a more effective front brake. Everything else can be "fixed" with the normal maintenance described in the manual or the replacement of parts due to normal wear.

Sure, there are convenience and appearance items that, depending on the individual, are very useful but that's a personal issue. For example, some folks think putting an E-start on a pre-MarkIII is sacrilege, others figure they are just doing what Norton had intended early in the Commando's production.
I have the exact same experience, owned my Norton the first time between 1974 and -84, never heard of wetsumping. Now I own the bike again and hear a lot of this potential problem, it´s very strange since it was no problem back in the day but now it is.....
 
I have the exact same experience, owned my Norton the first time between 1974 and -84, never heard of wetsumping. Now I own the bike again and hear a lot of this potential problem, it´s very strange since it was no problem back in the day but now it is.....
As we say in the software business, it was an unknown unknown to shade tree mechanics.

But, since Norton changed the OPRV return path, and added the mk3 ball/spring, my bet is they knew.
 
In my mind ,gear faces should be touched up too to prevent scoring on the mating surfaces. The reduction in capacity, I would think, isn't an issue.
Edit: maybe those little spurs on the gear tooth edges are there by design to dig into the mating surfaces during run in to help seal and should not be lapped.
I have rebuilt many Norton oil pumps. In fact I am just finishing another today. The gears are quite soft and should be inspected to ensure that the teeth are free of any inclusions, that the pump body is not unduly scored, , and the end faces do not have any burrs. I very carefully use a fine diamond file on the teeth to remove any small blemishes. The gears and bodies can and should be lapped to reduce end float. I recommend that owners read and follow the method as outlined in this excellent article by John Hudson. :)
 

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