Barn Find Gearbox... Water, Sludge & Rust

I drained the gearbox today and the first 3 minutes consisted of dripping water followed by back sludge. That got me worried so I pulled the cover and this is what I found...

Water, Sludge and Rust

Rust at 2:00 o'clock and on the clutch lever actuator.

I was really worried earlier, but when I came to post this information I saw SwooshDave's gearbox story and I now feel a little better...

What are my suggested "Next Steps"? Is there a way to clean this without a complete teardown? I've never assembled a gearbox before... Rebuild services from reputable suppliers seem to cost around $700 to $1000... I'd like to use that money for "Bling" if possible. Thanks for your help.

looks better than mine....

PhiloMcGiffin said:

What are my suggested "Next Steps"? Is there a way to clean this without a complete teardown? I've never assembled a gearbox before... Rebuild services from reputable suppliers seem to cost around $700 to $1000... I'd like to use that money for "Bling" if possible. Thanks for your help.

Click to expand...

The rust doesn't look too bad.

Rebuilding the gearbox is fairly simple and straightforward, and there's plenty of info on the OldBritts website and on this forum to guide you, and I'm sure you are more than capable of doing it yourself, and if you do hit a problem then somebody here will know how to help you through it, so there's no reason to pay someone else to do the job, but either way, the old drive side layshaft ball bearing really ought to be replaced with the roller bearing or Hemmings ball bearing, so the gearbox really does need to come apart.

http://www.oldbritts.com/ob_tech.html

My first gearbox had plenty of water in it and the layshaft and main shaft bearings were frozen with rust, the cam plate was eaten and the detent piston was rusted through, there was some kind of petroleum sludge to boot; I made this the first priority of my Mk III make-over.

The Norton gearbox is very simple, it can go back together only one way, as long as you don't force anything you won't hurt anything. Before you spend time and money on parts clean up the pieces and practice assembly and dissasembly, keep doing this until you can almost do the assembly blindfolded. When the time comes for a final assembly with your new parts and fresh gaskets it will yield some real pleasure and provoke pride; use this forum if you need guidance. About the only tricky proceedure is the alignment of the cam plate and quadrant. Your quadrant and cam plate are aligned correctly when the plate is in the first gear position and the right most end of the quadrant just makes it thorough the inner cover at the bottom of the "window" cut for it, do remember to place the shifting barrel in the quadrant before sending the inner cover home on final assembly.

Do check to insure that your gear dogs are flat and square and that none of the gear teeth are cracked, bent or missing, the gears with bushings with should not have perceptible radial play on their respective shafts.

Best wishes,

RS

Meh, if you can change a sparkplug you can rebuild a gearbox. :mrgreen:

If you get it wrong just try again. If the forum isn't a help (which I can't imagine it wouldn't be) then people talk about the Mick Hemming's DVD.

And the detailed instructions in the tech section of www.oldbritts.com