Open or not to open the oil pump
- Thread starter pierodn
- Start date
- Status
- Joined
- Jul 28, 2012
- Messages
- 1,132
Well, i read.pierodn said:
But i do not understand what means "thought the lapping had reduced the clearance between the teeth", or where should I lap and how much and where clearance must be eliminated.
In other words i know as manual says "i must correct end float on the feed gears (the narrows one) first" but i dont understand, i cannot able to translate and know it.
Thanks.
Piero
- Joined
- Nov 20, 2004
- Messages
- 20,415
Thanks!
I have seen and read "Norton Companion" and it says: "NOTE: The feed gears have a chamfer on ID - this goes inboard. You can see it (sorta) on the LEFT gear above. The other side has no chamfer and that goes against the brass plate.".
Well I have a doubt:
- all my pumps have the both feed gear with chamfer: one is is correctly fitted into the body against the brass plate (as Norton Companion says), but also on the other side (the side where is the worm gear out) the feed gear has a chamfer side that is fitted against the black plate (not into the body) ahead to worm gear.
Is it correct mounted?
I need your sugestions, please.
Ciao.
Piero
I have seen and read "Norton Companion" and it says: "NOTE: The feed gears have a chamfer on ID - this goes inboard. You can see it (sorta) on the LEFT gear above. The other side has no chamfer and that goes against the brass plate.".
Well I have a doubt:
- all my pumps have the both feed gear with chamfer: one is is correctly fitted into the body against the brass plate (as Norton Companion says), but also on the other side (the side where is the worm gear out) the feed gear has a chamfer side that is fitted against the black plate (not into the body) ahead to worm gear.
Is it correct mounted?
I need your sugestions, please.
Ciao.
Piero
Hi Dave,DogT said:
Sure, Norton Companion and manual says the same thing but only for the feed gear that goes into the body to the brass plate.
But alo the other feed gear that goes to the other side, to blak plate, has a chamfer: it goes into the body or against the plate?
This is the question.
Ciao.
Piero
I will try to be more clear:
I have seen and read "Norton Companion" and it says: "NOTE: The feed gears have a chamfer on ID - this goes inboard. You can see it (sorta) on the LEFT gear above. The other side has no chamfer and that goes against the brass plate.".
Well I have a doubt:
- my pump has both the feed gears with chamfer: one is is correctly fitted with the chamfer side into the body and the flat side against the brass plate (in according to Norton Companion), but also the other side of the body, where is the worm gear, the feed gear has a chamfer side that now is fitted against the black plate (not into the body where is fitted the flat side.
Is it correct mounted?
I need sugestions.
Ciao.
Thanks
Piero
I have seen and read "Norton Companion" and it says: "NOTE: The feed gears have a chamfer on ID - this goes inboard. You can see it (sorta) on the LEFT gear above. The other side has no chamfer and that goes against the brass plate.".
Well I have a doubt:
- my pump has both the feed gears with chamfer: one is is correctly fitted with the chamfer side into the body and the flat side against the brass plate (in according to Norton Companion), but also the other side of the body, where is the worm gear, the feed gear has a chamfer side that now is fitted against the black plate (not into the body where is fitted the flat side.
Is it correct mounted?
I need sugestions.
Ciao.
Thanks
Piero
- Joined
- Nov 20, 2004
- Messages
- 20,415
DogT
VIP MEMBER
- Joined
- Jan 20, 2009
- Messages
- 7,394
Seems to me my gears came out with the chamfer on the same side for both gears. I put it back in the same way, but I don't see it written down anywhere. It looks to me like norbsa's pictures are different with the chamfer. Is that confusing or what? I would think it would be the same for both, but we need an expert.
Dave
69S
Dave
69S
- Joined
- Apr 7, 2004
- Messages
- 1,691
I fixed the old picture it's gone now.In that picture the gear had flipped over before putting it back in. Sorry for confusing anyone. Been through about twenty more pumps since this one don't be shy take it down and find out whats inside.
- Joined
- Oct 19, 2005
- Messages
- 18,978
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.
Factory manual 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
Sealing mods to consider
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
Factory manual 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
Sealing mods to consider
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
norbsa48503 said:
Dear Norsba,
I understood well the feed gear goes with chamfer side into the body (not against the brass plate).
But i need to know about the other feed gear but none reply to me!!!!
I need to know if the feed gear fitted to the other side of the body that have a chamfer side the same, goes into the body or against the black plate (my oil pump has fitted agaist the black plate).
Please, someone can tell me where goes correctly?
I would to know it, not the feed gear on brass plate side.
Thanks.
Ciao.
Piero
DogT said:
Hi Dave,
is correct the second pictures, with flat side gear against brasse plate and chamfer side (we cant see) into the body.
But .... in the other side (to worm gear) my pump had fixed the chamfer side against the black plate!!!!!! not into the body!!!
Why noone replay to me?????
Nobody knows it???
Please, could you help me?
Thanks.
Ciao.
Piero
- Joined
- Nov 20, 2004
- Messages
- 20,415
pierodn said:
Piero, I hope you will understand that servicing the oil pump is not something the average Commando owner does on a regular basis, and many owners will never have done it, so most of us will either not know or will not recall (as I cannot) exactly which way the chamfer on that gear goes, I am sure this is the reason for the lack of response.
A quick phone call to Mick Hemmings would probably get you the answer you need?
DogT
VIP MEMBER
- Joined
- Jan 20, 2009
- Messages
- 7,394
So the feed side gears (narrow gears) that operate against the brass plate have the chamfer in the body side.
The scavange gears (wide gears) that operate against the steel cover plate also have chamfers? I don't remember. I would assume they would be like the feed gears, with the chamfer to the inside, but yes it may be wise to call someone that knows for sure, I'm sure Mick would tell. I can't remember. I didn't realize Piero was asking about the wide gears.
It always helps to call things as they are in the workshop manual or parts book, I'm guilty of the using non standard names at times.
Dave
The scavange gears (wide gears) that operate against the steel cover plate also have chamfers? I don't remember. I would assume they would be like the feed gears, with the chamfer to the inside, but yes it may be wise to call someone that knows for sure, I'm sure Mick would tell. I can't remember. I didn't realize Piero was asking about the wide gears.
It always helps to call things as they are in the workshop manual or parts book, I'm guilty of the using non standard names at times.
Dave
- Status
Similar threads
