Tempering soft steel (1 Viewer)

[canucksafari]

Decided to fix the broken hubs rather than go and buy new AVM hubs for the other Safari. These hubs are auto hubs but can also be manually engaged. I'll likely mod the hubs by taking out a small spring to make them manual hubs. Got a local machinist making up two spacer rings and some metal tabs - see pics below. On one hub the spacer is completely broken and the other has a crack. The metal tabs are also either broken or on their way out. The tabs are what locks or unlocks the hubs manually. The machinist tells me that they are spring steel and he can't cut spring steel - so I will have to harden them after he's done making them. My question is how many times should I heat them to cherry red and dip them in oil to get them about as hard as spring steel? I don't want them too hard or they will just shatter.

Broken spacer on hub clutch:

Cracked spacer with broken tabs:

Tabs inside hub housing:

 

[hamberger]

Do you have a forge? Your going to need very "even" heat especially with such thin material.

I'm not a metallurgist but I have done some very basic Blacksmithing. Like drawing out and re-pointing Picks and chisels.

Blue is brittle
Yellow is tempered
orange is soft.

Your probably looking for something between the blue and yellow stage

Have a bucket of oil
Have a bucket of ice cold water
Have a good file

Heat your material dark red hot
Dip it in oil for a second or two.
Stroke your material with the file and see what color hue the file marks are
Keep dipping in oil and file till you start getting orange.....then stop oil dipping and stroke with file every few second (because your material is so thin you have to work fast) until you get color changing to blue streaks and then as fast as you can get it into the cold water.

This is a very old technique that works best on large stock that you can see the color travel the length of your stock to the heated end and may not work so good on such small material thats entirely heated.

Personally I think trying this is going to be hit and miss.

ham

 

[13B-T BJ60]

Maybe this will help:
Hardening and Tempering

 

[canucksafari]

Thanks for the replies. I figured this wasn't going to be easy because the material spacer ring material is so thin but also has a good size surface area so even heating is going to be hard to achieve. I've done this many years ago in high school shop making a knife blade. It wasn't that hard but we had a professional forge to work with. Worst case scenario is it doesn't work and I have to buy a set of AVM hubs.

 

[Enigma]

T Worst case scenario is it doesn't work and I have to buy a set of AVM hubs.

Or buy something a little more standard (in this part of the world anyways), like Warn hubs? I'm assuming Warn makes them for a Nissan.

 

[canucksafari]

Or buy something a little more standard (in this part of the world anyways), like Warn hubs? I'm assuming Warn makes them for a Nissan.

Nope. I checked and Warn doesn't do a 31 spline.

 

[Abitibi]

Hi John,

Have you looked at the Superwinch? Not sure if these would fit but they are 31 spline on 6 bolts for Nissan. They seem to still be available at some shops, here's one just for an ex.

Superwinch 400545 Superwinch 4x4 Front Hubs

Cheers,
David

 

[canucksafari]

Hi John,

Have you looked at the Superwinch?

Yes, in fact I have a set on now. They look like decent hubs. Still I will finish the Nissan ones up and have a blacksmith harden and temper the parts i had made up. The Superwinch hubs were only about $125 US a set delivered to Sumas. The Aussies pay close to $400 AUS for a set of these.

 

[Abitibi]

Good to hear, where did you get them, that's a good price. Summit Racing?

There's also a set of AVM on ebay
New Nissan 4x4 PU Nissan Patrol 90-94 AVM Hub:eBay Motors (item 350291346892 end time Jan-08-10 14:16:10 PST)

but I'm more familiar with superwinch as I currently run them on my truck and they've been trouble free for 1yr now.

As you can tell I slowly started the parts improvement process...

Cheers.
David

 

[canucksafari]

Got them at StreetSideAuto.com. After more reading, I decided to avoid the AVMs because they break too easily.

 

[Abitibi]

Can't seem to find anything at StreetSideAuto, they only have Warn and Mile Marker which don't come in 31 splines? I'll keep on looking. Since it's one of the rare weakness on the Safari *wink* might as well get it over with...

David