The cover is off....
- Thread starter MikeG
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Do what ever you can while in there. Pulling and checking the pump is easy enough.MikeG said:
Did you get e fresh conical seal that goes between the pump and the timing cover as well as the crank seal for that side?
P.S. Don't forget about the need to protect the seal when putting the cover back on.
Only if needed. Go ahead and take out any over play but be careful and keep it square and free turning. The body is cast iron and material will be remove with ease. That nut holding the gear on can be a bitch.MikeG said:
Do you have issues that you feel you need to address in this regard (I am not going to say it)?
Be sure to check the oil holes behind the pump and throughout the timing cover.
If your pump has issues as seen below, don't waste your time.
Look for scoring or scratches in the seal points.
And marring on the gears. Not good!
MikeG
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[quote="pvisseriiiDo you have issues that you feel you need to address in this regard (I am not going to say it)?
The dreaded wet sumping issue (I hate to say it). I had really planned on addressing this in the winter by having the pump and cover modified al la AMR, but I'm replacing the points seal now. No other known issues with pump at this point.
The dreaded wet sumping issue (I hate to say it). I had really planned on addressing this in the winter by having the pump and cover modified al la AMR, but I'm replacing the points seal now. No other known issues with pump at this point.
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No real need to attend to pump which needs 3 specific spacers to seal each
Cdso model 750 or 850 as long as all 3 are the matched combined thickness.
Gasket under the oil pump, or not, thickness of end nipple and thickness of the TS cover gasket, the only one really needed in our engines. No real need d/t the oil sling by crank to fed rods runing so only need enough extra pressure to trickle some oil into head as cam gets sprayed good by the crank sling too. Pump gets worn by inhaling ferric grit for rings/bores and sometimes thrust washer tab and of course on blow ups. There's about 6 different areas that can leak pump pressure and ways to upgrade but that's another subject you can search up. Otherwise its routine to just fine sand down the side plate so fits flush as can to the cog sides.
If wanting to feel self satisfied to Nth degree, which is a good thing now and then, follow DynoDave's instructions here...
3 orings....
2 on the rotating main shaft,
one between the feed and scavenge side gears
and one between the scavenge gear and the drive geat.
The shaft is ground with grooves to sliding oring fit tolerances.
1 on the idler shaft between the feed and scavenge side.
This shaft is stationary and the gears turn, therefore, this
shafts is ground with a groove to stationary oring fit tolerances.
These groove tolerances are easy enough to find, sorry I don't
have the numbers readily at hand.
FWIW There are four possible wet sump leakage paths in a norton
oil pump and lapping the ends only address one.... shaft orings address the
second. 3rd= gear to gear wear 4th=gear tip to pump body wear
dave
The Mark III seal is thinner than the other. It has a small taper then flattens out, whereas the other has kind of a dome.
Here is what my factory manuel says Section C30 / 11 third paragraph ...Very late engines use a joint gasket between the oil pump and crankcase joint faces and where a joint washer is used at this point, under no circumstances should the conical rubber seal between the oil pump and timing cover be equiped with packing shims....
Para 13, Fit a new conical rubber oil seal part number NMT272 on the oil pump outlet stub and dispense with any shims which may been fitted between the seal and pump body at the time of dismantling. Over compression of the seal will render it unfit for further use.
It appears part of the shimming process is the paper gasket behind the oil pump, and when used with the proper seal and stub outlet, should get the proper clearances without shims.
The '75 and later 850 MkIII had a different seal that didn't require shims. All other Commandos both 750 and 850 used the conical seal and required checking to make sure there is compression. The amount of compression is just enough to make a seal, don't completely flatten the seal. The doubt I have is .020" is a lot of shim and I haven't needed shims in the past. Better to check again and waste the seals. Then on to the blown crankshaft seal in the primary.
Just one more word of caution about eliminating gaskets: the oil pump gasket is .007" thick, so eliminating it will reduce the compression on the oil pump seal by this same amount. This could mean the difference between adding shims or not on the older twin chain motors. Or, possibly an ineffective seal if shims aren't used to make up the gap.
There are 4 things to consider in seal fit of pump to TS cover. oil pump/crankcase wispy gasket, shim under pump nipple, thickness of pump nipple and thickness of TS cover gasket. Here's the recommended combo for all Norton twins below.
Walridge Motors catalog:
Note - Later, thicker Commando type timing cover gasket [06-1092] is recommended for use on all 500-850 twins, but MUST be used in conjunction with oil pump gasket 06-2447 to ensure correct positioning of the oil pump vs timing cover.
Timing Cover all yrs, p/n 06-1092
Oil Pump all yrs, p/n 06-2447
Oil Junction block all yrs p/n 03-2044
Cdso model 750 or 850 as long as all 3 are the matched combined thickness.
Gasket under the oil pump, or not, thickness of end nipple and thickness of the TS cover gasket, the only one really needed in our engines. No real need d/t the oil sling by crank to fed rods runing so only need enough extra pressure to trickle some oil into head as cam gets sprayed good by the crank sling too. Pump gets worn by inhaling ferric grit for rings/bores and sometimes thrust washer tab and of course on blow ups. There's about 6 different areas that can leak pump pressure and ways to upgrade but that's another subject you can search up. Otherwise its routine to just fine sand down the side plate so fits flush as can to the cog sides.
If wanting to feel self satisfied to Nth degree, which is a good thing now and then, follow DynoDave's instructions here...
3 orings....
2 on the rotating main shaft,
one between the feed and scavenge side gears
and one between the scavenge gear and the drive geat.
The shaft is ground with grooves to sliding oring fit tolerances.
1 on the idler shaft between the feed and scavenge side.
This shaft is stationary and the gears turn, therefore, this
shafts is ground with a groove to stationary oring fit tolerances.
These groove tolerances are easy enough to find, sorry I don't
have the numbers readily at hand.
FWIW There are four possible wet sump leakage paths in a norton
oil pump and lapping the ends only address one.... shaft orings address the
second. 3rd= gear to gear wear 4th=gear tip to pump body wear
dave
The Mark III seal is thinner than the other. It has a small taper then flattens out, whereas the other has kind of a dome.
Here is what my factory manuel says Section C30 / 11 third paragraph ...Very late engines use a joint gasket between the oil pump and crankcase joint faces and where a joint washer is used at this point, under no circumstances should the conical rubber seal between the oil pump and timing cover be equiped with packing shims....
Para 13, Fit a new conical rubber oil seal part number NMT272 on the oil pump outlet stub and dispense with any shims which may been fitted between the seal and pump body at the time of dismantling. Over compression of the seal will render it unfit for further use.
It appears part of the shimming process is the paper gasket behind the oil pump, and when used with the proper seal and stub outlet, should get the proper clearances without shims.
The '75 and later 850 MkIII had a different seal that didn't require shims. All other Commandos both 750 and 850 used the conical seal and required checking to make sure there is compression. The amount of compression is just enough to make a seal, don't completely flatten the seal. The doubt I have is .020" is a lot of shim and I haven't needed shims in the past. Better to check again and waste the seals. Then on to the blown crankshaft seal in the primary.
Just one more word of caution about eliminating gaskets: the oil pump gasket is .007" thick, so eliminating it will reduce the compression on the oil pump seal by this same amount. This could mean the difference between adding shims or not on the older twin chain motors. Or, possibly an ineffective seal if shims aren't used to make up the gap.
There are 4 things to consider in seal fit of pump to TS cover. oil pump/crankcase wispy gasket, shim under pump nipple, thickness of pump nipple and thickness of TS cover gasket. Here's the recommended combo for all Norton twins below.
Walridge Motors catalog:
Note - Later, thicker Commando type timing cover gasket [06-1092] is recommended for use on all 500-850 twins, but MUST be used in conjunction with oil pump gasket 06-2447 to ensure correct positioning of the oil pump vs timing cover.
Timing Cover all yrs, p/n 06-1092
Oil Pump all yrs, p/n 06-2447
Oil Junction block all yrs p/n 03-2044
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hobot said:
Its coming down to a bunch of pieces that need to be right in alignment for that conical seal to fit right!
I am doing the process now and I am awaiting the conical seal. I ordered the shim too but only because I saw it on the microfische.
What is the result of a bad or uneven seal with the conical seal?
Greate poist btw, great timing for me at least!
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Poor seal pumps oil into the TS case w/o as much supplied to the crank and head. Might check the seal and area around it in the TS cover I'd seen bust out a chip like Peel over rev crank whip did. Pressure can hit 100 PSI when cold they say. As gasket needed here I hylomar to the cover and grease the case side as if ever need to replace the gasket its easier to clean old goop off cover than case face.
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hobot said:
lb for lb you have a good information per word ratio!!! Thanks!
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