Gearbox selector/pawl strip, early NH

[Phil B]

Tomorrows job is to find out why the gearbox selector isn’t working. It’s sequential but not self centreing (sp?).

Any tips welcome, does the selector pawl mech come off with the outer cover? I assume the kicker does.

It’s been stood 20 years so not sure what to expect!!

Hopefully the pic will give the type to those in a position to advise.

Thanks in advance.

[Phil B]

It’s a 1939 NH 350 btw.

[simon.holyfield]

Any tips welcome, does the selector pawl mech come off with the outer cover? I assume the kicker does.

Yes it does. There's some useful information on my blog, a popular blog post called 'Spend a Night in the Box'.

[john.whiting]

it will be one of the coil springs in the selector box /ratchet assy directly inside the footpedal.Replace the lot,if you can still buy new ones.The problem is usually caused by corrosion embrittling the springs,which then break.Or you could call it plain old age.

[Phil B]

Thanks chaps, most helpful.

I’ll strip it first but if it is the springs, do you have a source for the new ones in mind?

Also (I said when I joined that I’d have a thousand daft questions!), what type of grease is the best modern equivalent please?

[brenton.roy]

Hi Phil, we love daft questions
There's a handy diagram here and I assume you can buy the springs. https://www.draganfly.co.uk/index.php/a ... ba-gearbox. I expect you can fairly readily get BA parts at a number of retailers, or maybe via club spares.
There was a discussion about gearbox fluid / grease a week or so ago. http://forum.arielownersmcc.com/viewt ... =48&t=7067
regards, Brenton

[john.whiting]

I suppose Draganfly would be your first enquiry,but spares for WW2 Matchless boxes were once very plentiful,so might be worth trying Matchless suppliers.................There is a type of grease now on the market...Penrite Vintage steering box grease......,has many admirers.Personally I have enough lubricants,and will make do with something I have in the way of mixed grease and heavy oil.

[Phil B]

Thanks all, most helpful.

I have a few different grease types on my van for work. I could experiment mixing with a bit of EP90 gear oil.

[simon.holyfield]

I think I may have a few spare springs.

[Phil B]

Springs are deffo the issue Simon. The two smaller springs that direct the pawl to the ramps on the selector were bunged up with old solid grease.

But even after cleaning the springs were one sided, making selection a bit hit and miss.

The gear levee centralises now but doesn’t always select, and sometimes overthrows, and goes straight past a gear.

Also, the main box now has some lube in it!!!

Poor thing was dry. Put a whipped up mixture of a basic moly grease and EP90.