Gear Box Question

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Deets55

Deets55

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The gear change quadrant on my MKIII is leaking like crazy. On AN‘s site I see there is an “O” ring, part number 04.0129 (21A inner cover parts diagram). It doesn’t show which side of the case to install it. I ordered a master gasket kit from Old Britts and it comes with 3 of those ”O” rings, but their parts diagram doesn’t even show the part. So I have no idea where they all go. I don’t recall installing one when I did a rebuild 10 years ago and it stayed dry until recently. If the “O” ring goes under the washer part # 22 and against the case is there anyway to install it without tearing the entire gearbox apart. Looking at it I think it looks impossible. Thanks in advance for the help.
Pete
 
Deets55 said:
The gear change quadrant on my MKIII is leaking like crazy. On AN‘s site I see there is an “O” ring, part number 04.0129 (21A inner cover parts diagram). It doesn’t show which side of the case to install it.
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On the outside behind the washer and circlip.

Deets55 said:
I ordered a master gasket kit from Old Britts and it comes with 3 of those ”O” rings, but their parts diagram doesn’t even show the part. So I have no idea where they all go.
Click to expand...

There should be one each for the quadrant, camplate and Mk3 camplate plunger housing/bolt '40'.

Note that O-ring '19' 04.0079 was "Deleted - Not required".
 
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Taken from memory, remove quadrant screw, washer and O-ring.. Fit new O-ring. Retighten. A year since last renovated one, memory might have faded.
 
Mike40M said:
Taken from memory, remove quadrant screw and washer. replace O-ring. Retighten. A year since last renovated one, memory might have faded.
Click to expand...

The Mk.3 quadrant has a circlip, not a screw/bolt.
 
This is a pre-MK3 gearbox, but you get the idea.

I always smear my o-rings with some grease before fitting - it will help prevent tear out damage when you’re assembling.

Gear Box Question

Gear Box Question

As I say, pre-MK3 so no hole for neutral indicator.
 
Thanks for the quick replies. Guess I have to open up the case to get to the quadrant “c” clip. Too much stuff in the way from the bottom.
 
Deets55 said:
Thanks for the quick replies. Guess I have to open up the case to get to the quadrant “c” clip. Too much stuff in the way from the bottom.
Click to expand...

The circlip is on the outside. Edit Possibly easier to remove the primary cover and pull the cross shaft and coupling out of the way rather than removing both gearbox covers. Re-edit It's still difficult without a long pair of angled external circlip pliers.
 
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The text in the Factory Workshop Manual is correct:

Gear Box Question


However, the picture is incorrect, as it shows a pre-MK3 without the circlip:

Gear Box Question


The exploded view diagram is correct though, showing the circlip:

Gear Box Question

Gear Box Question
 
Sorry, did not notice that it was a Mk3.
Anyhow, if leakage is due to a heavily worn bushing, making it impossible for the o-ring to seal properly, disassembly will be needed.
When fitting a new bushing, it is important to position it right.
Special tools easily made if you have a lathe,
 
There are services that will machine the gearbox and fit a standard oil seal; good chance they can install/ream the bushing at the same time if you are not comfortable replacing/reaming the new bushing; especially in this instance where the stakes are high and MK3 g/b shells are rare (and expensive).

Best.
 
Took the gear box apart. Just finished getting it together. Gonna eat, clean up the mess and try it out. Thanks for all the input.
 
Les,
Everything was in place. “O” ring must have given up the ghost since the last time it was replaced. I just had the box apart to replace some bushings and a broken 3 rd gear. I ordered the parts from AN and must have missed the “O” on the parts break down. Last time I had it apart was a long while ago and I just forgot about it. I also switched from Shock proof lube to a lighter Bel Ray lube. I guess the Shock proof was heavy enough not to past through the worn seal but the Bel Ray ran through like water.
Just did 50 miles and a good highway run and came back dry. Hopefully it stays that way.

Thanks,
Pete
 
I recently switched from shock proof to Bel Ray and now have a leak out of the clutch cable entry point I’ve not had before!

I am choosing to see it as a good sign of the oils searching and lubricity properties ...
 
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Fast Eddie said:
I recent switched from shock proof to Bel Ray and now have a leak out of the clutch cable entry point I’ve not had before!

I am choosing to see it as a good sign of the oils searching and lubricity properties ...
Click to expand...

I try not to post negative comments on anything because of just my personal experience. There are too many variables involved. I will say that I was not impressed with the Shockpoof in this particular case. I will also say the Bel Ray was in every nook and cranny and slick as goose sh*t.
I think you will be pleased Nigel. You may have to install that brass vent in your outer case now;)
Pete
 
Note that O-ring '19' 04.0079 was "Deleted - Not required

I have recently rebuilt my gearbox and went to the extent of fitting O ring #19- 04.0079. why was it deleted/ not required? though I could not understand its application but as it was listed [even on Andover's site] i went ahead and fitted it will this cause me a problem?
 
possm said:
Note that O-ring '19' 04.0079 was "Deleted - Not required

I have recently rebuilt my gearbox and went to the extent of fitting O ring #19- 04.0079. why was it deleted/ not required?
Click to expand...

Because as far as I'm aware, the 04.0079 O-ring shouldn't have been drawn on the diagram in the first place and it is too small to fit at the location shown on the Mk.3 diagram without stretching it as that O-ring is intended to fit the groove on the pre-Mk.3 RH shift ratchet plate spindle (below).

andover-norton.co.uk

Andover Norton Parts Drawings - Genuine Andover Norton Factory Parts - Commando Parts

Andover Norton Parts are the only Norton spare parts in the market manufactured to original drawings, within the factory-approved tolerances, from the correct materials, and with the correct finish.
andover-norton.co.uk
Gear Box Question



possm said:
though I could not understand its application but as it was listed [even on Andover's site]
Click to expand...

Unfortunately, AN copied several errors from the original parts books. This appears to be one of those errors.

It wasn't (and still isn't) in my Mk.3's gearbox and other Mk.3 owners have said the same.


possm said:
i went ahead and fitted it will this cause me a problem?
Click to expand...

Probably not.
 
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Thanks L.A.B. that's appreciated, as stated I couldn't work out its use.
 
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