How to tighten the oil pump shaft lock nut?

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disquek

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Hi,

I just bought a new oil pump, key, and lock nut.

I see no way other than holding the gear to tighten the lock nut.

Is there a trick to this? On the high end, I guess I could make a custom strap wrench kind of thing to grab the OD of the gear. On the low end, I could put the gear in a vice with soft jaws in it.

Any other thoughts? I searched high and low here and didn't find an answer in any thread.

-Kyle
 
Ah well, and I had such a nice collection of brass drifts. :-(
 
Swooshdave, Nope. Once it's in place you cannot get a socket on the nut. I supposed you could get an open end wrench on it, and forgo torquing it.
 
disquek said:
Swooshdave, Nope. Once it's in place you cannot get a socket on the nut. I supposed you could get an open end wrench on it, and forgo torquing it.
Click to expand...

You should be able to get a spanner on it. I don't see the torque spec for that nut, do you have one? I don't think it has to be crazy tight, but a little Loctite and it should be ok. Hopefully someone smarter than me can correct me if I'm way off.

Here's a cool page on servicing the oil pump. They don't remove that drive gear so it doesn't help you directly.

http://www.doov.com/apps/nortoncomp...ry-transmission/19-c25-servicing-the-oil-pump

You can see on this page an illustration from the service manual on getting a spanner on that nut. Drawings can lie but maybe it would work?

http://www.doov.com/apps/nortoncomp...ransmission/18-c16-dismantling-the-crankcases
 
Thanks Swooshdave,

You can certainly get a box end wrench on it.

I did find what I thought was a torque spec for it of 25ft/lbs here: https://www.oldbritts.com/n_torq.html

That does seem a little too high for what seems close to a 5/16" fine thread. I'm thinking you've got the winning answer here. To just use a box end wrench and tighten it in the bike.

-Kyle
 
And Loctite.

I still think you could do it off the bike with some visegrips, carefully. I believe 25 lbs is what the con rod nuts are and it’s not that much.
 
My impression of the torque specs on the various websites and shop manuals is that they are, or become, broad based suggestions. On a Commando the only fastening systems I take dead seriously are the connecting rod bolts, the clutch hub nut and the ISO nuts.

The oil pump gear can be comfortably tightened by feel* while the pump and its helical gear are in place.

* by feel: If you haven't bent, stripped, cross threaded or otherwise mangled 1000s of fasteners by now, you have no feel. If you even wonder about the wisdom of the old cliché: "Tighten 'em down till they strip, then back 'em off a 1/4", you have no feel. If you can't make a screw driver function in a multitude of other modes, you have no feel.

If you have no feel then clamping the oil pump drive gear in any vise with any buffering material will get you on the road to hell in short order, damned if you do, damned if you don't. If you have learned the ways of the feel, the correct force will always be with you; you'll be the kind of lover any partner will treasure...

If you have no feel and are messing around with an engine that can easily turn into a hand grenade, all be it a bit heavier, get someone else to help you, they will be honored and you can maintain your sanity.

All the best.
 
I never see the use of hammers mentioned. It's another tool in which "feel" is required, but the correctly-sized hammer on the correctly-sized wrench and the hammer will bounce when the proper torque is reached. Like anything else, ham-handedness or too much tool will get you into trouble.

Ron Wood was asked about the differences between a Norton and an XR-750 when he finally gave up trying to keep the Nort in one piece and he said "I had to get bigger hammers"
 
RoadScholar said:
My impression of the torque specs on the various websites and shop manuals is that they are, or become, broad based suggestions. On a Commando the only fastening systems I take dead seriously are the connecting rod bolts, the clutch hub nut and the ISO nuts.

The oil pump gear can be comfortably tightened by feel* while the pump and its helical gear are in place.

* by feel: If you haven't bent, stripped, cross threaded or otherwise mangled 1000s of fasteners by now, you have no feel. If you even wonder about the wisdom of the old cliché: "Tighten 'em down till they strip, then back 'em off a 1/4", you have no feel. If you can't make a screw driver function in a multitude of other modes, you have no feel.

If you have no feel then clamping the oil pump drive gear in any vise with any buffering material will get you on the road to hell in short order, damned if you do, damned if you don't. If you have learned the ways of the feel, the correct force will always be with you; you'll be the kind of lover any partner will treasure...

If you have no feel and are messing around with an engine that can easily turn into a hand grenade, all be it a bit heavier, get someone else to help you, they will be honored and you can maintain your sanity.

All the best.
Click to expand...

The old story about torque settings is that a mechanic from a famous company assembled an engine as he always did, this time using a wrench supplied by the boffins that could measure the torque he applied. After he assembled the engine, they then published the resulting "torque" specs. I agree that you can "feel" proper tightening for most fittings ASSUMING you consistently use appropriate tools. IOW, don't use a 1/2" drive ratchet to tighten the hex screws on the handlebar switches, etc. ;) Admittedly, when starting out, it is easy to strip aluminum threads until you develop that "aluminum feel" but heck, that's why they make helicoils! :)
 
Did we decide on the answer to the original question: What's the 'correct' / 'accepted best practice' way to tighten the oil pump gear nut ?

I honestly cannot recall what I did last time, and I've another to do soon, it'd be nice to do it 'properly'...
 
correct procedure?...
Bernhard said:
Engineer’s vice with some soft jaws inserts holding gear . . . .
Click to expand...

2 bolts or nuts (depending on year/engine series) and the pump is in your hands in under 15 seconds. I've done this hundreds of times.

I have never come even close to damaging the oil pump gear in a soft(aluminum) jaw vice, even if crushing the hell out of it.
old pumps 3/8-26 cei new/late 3/8-24unf
torque with box to 20-25(max) ft/lb or even better socket/torque wrench.
IMO never on engine, no way no how
If you over tighten, you will mash the softer shaft end a bit, as the gears are hardened. You will notice the mashed shaft next time you disassemble the oil pump...
Have you seen broken crank gears? (I have)
The oil pump gear is not normally the one that breaks.(never seen one)
 
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Fast Eddie said:
Did we decide on the answer to the original question: What's the 'correct' / 'accepted best practice' way to tighten the oil pump gear nut ?

I honestly cannot recall what I did last time, and I've another to do soon, it'd be nice to do it 'properly'...
Click to expand...

I suspect, but don't know for a fact, that the works had a female gig that would accept the oil pump gear so that the nut could be tightened to any level of torque they desired.

Clamping the gear in a vice is too scary for me, even with wood faced jaws; I tighten the nut in situ in a smooth, gentle motion with slowly increasing torque until I get the feel I want; I use a new nut, and mostly a new pump. Never had any issues.
 
Thanks Guys! Your advise is awesome!

I used a soft jaw thing I had that has triangular cut outs (it's made for assembling AN hoses) and it held the gear beautifully. I torqued it to 21ft/lbs with blue loctite. Honestly, 21 was where my nerves gave out. lol. That's awful tight for that little nut!

The original nut wasn't anywhere near that tight. When I was testing the setup, it was spinning the nut at 11 ft/lbs (digital torque wrench). So I think 21 ft/lbs will be fine. The original was peened twice, but the new nut is a locknut.

Thanks again for the help!

-Kyle
How to tighten the oil pump shaft lock nut?
 
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Jeez, some people always find the hard way! :rolleyes:

I have always used the soft aluminium jaws in the vice, but because you are not looking at a high torque figure I have always been able to hold it with the pump at an angle, nut uppermost for easy wrench access!

And as you said, it is a locknut, so what is with the loctite!

I have had to pull two of these off in the last two years as the current supply of gears seems to be too soft....see other threads.

PS: if someone has a new old stock pump gear or a used one in very good condition I would love to hear from you.

I managed to find a NOS worm, but no pump gear.
 
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lol. I have a talent for finding the hard way.

I was advised by a very experienced Norton guy to add the loctite. Likely not needed. But he's one of the people whose advise I follow without question.

I will look for those threads about soft gears. That's concerning.

-Kyle
 
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