Technical 1939 ? cluster - can a tooth be welded

I have a 39 trans with an earlier gear set - 51A-7113 - there are no new clusters and so far
I haven't found a good used one. My question revolves around the 1st gear set teeth
(next to reverse) one tooth has a chip and ones on each side of it have bad lead in edges.
Is it possible to TIG weld up these teeth and then profile them back to a functional state?
If so, how would you go about it, and if not - why not?

 

Heat from welding changes the metallurgy of the gears.

 

Ah heck, go for it.

Instructional video on the U toob -

 

Those gears are harder than a *****s heart. Welding the tooth would make the immediate area around the weld softer and likely fail in short order.

 

Of course you could. Can. And depending on your skill do a fine job of it. Depending on the filler metal, silicon bronze versus a ER80S for instance, outs comes for resulting hardness will be limited if heat input is controlled, but it isn't rocket science either. Just my two cents worth.

 

Absolutely NO!!

 

Have you checked with Mac VanPelt on part availability?
http://www.vanpeltsales.com/

 

Those guys are amazing. There is a whole series of videos of things they build in poor work conditions. I think it is mostly in ****stan.

 

In the video, you do what you can with what you have. That isn't much different than what we did years ago. I'll bet many farmers can relate to the video.

 

Hey, if it works for a while, more power to them. Me, I'd be using a torch and a temple crayon to draw it down a tad... and you know they are not going to be checking the contact patterns...

 

I work with two guys from Guyana.
They are amazing “ backyard mechanics” you need a piece of equipment up and running at 4pm on a Friday send Raj or Sugrim with a coat hanger and a roll of duct tape snd they will make dreams come true until the right parts show up.

they both said the same thing ,when you live on an island , a poor island . Even IF you had the money you can’t get what you need so you make what you have work .

without getting the gears hardened after welding , not sure if you even could . I don’t think they would last that long .

 

I would want to TIG it with stainless 308 or 309 wire. Pre-heat it and then gradually cool down.
Thinking maybe the stainless would be harder!??
Why not smooth off the edges and run as is?!.....Not like your drag racing it, right!?
6sally6

 

Exactly.

 

It's a good thing nobody told the blacksmiths of years gone by that gears couldn't be built up and repaired! You do what ya gotta do, or sit and watch the world go by...

 

So what is better then, a half chipped off tooth as in the second pic that has,nt been heated by repair or that chipped tooth repaired and ofcourse heated up ?

 

Dad had a ring gear spacer made for his '65 Catalina wagon rear axle years back because we couldn't find the right carrier. To make sure it stayed in place, we bolted the gear and spacer to the carrier using longer bolts then had it welded. Our welder was certified and knew what he was doing. I was in charge of the torch and heat crayons, while he welded. We made one p*** all the way around the carrier and spacer, and one around the spacer and gear. Once welded I kept it hot while he prepped the bucket. It was filled about half full of dry concrete, we set the ***embly in and filled the rest of the bucket. It stayed in there for three days to slowly cool. Dad made a lot dragstrip p***es using that set up, it held up good in the 4800lb wagon running low 13 et's. He sold the ***embly to a fellow 4 speed racer when the wagon got to rusty to keep racing. Last we knew the gear was still in use. I doubt welding one tooth would heat the gear any more then we did welding the whole ***embly.

 

But you didn't weld the gear teeth, did you?

 

I bought a '68 Delta Rockwell lathe that had a broken back gear cluster. I bronze welded up a tooth and filed it down. It has survived. When I am using the back gear I take light cuts.
I would think the length of time it lasts is inversely proportional to how hard you launch the car, which is probably how the gear got in the shape its in right now.
Restraint

 

If you're not racing it, I wouldn't worry too much about it. The broken tooth will hold up to everyday driving but the worn teeth will make noise. I have a really noisy low gear in my A-V8 but I just take off in second gear. It really doesn't need low gear. I'll use it until a sudden rush of ambition happens and I'll install a better transmission.

 

Amazing how many ring gears he had there to fix. Must "rebuild" them regularly

 

"Damned if you do and Damned if you don't............

If I were to do it, I would use tig only. The leading edge of the tooth helps guide the gear into position so the main body of the tooth can hold the torque. Hopefully you don't release the clutch until complete engagement is made.

Then on the other hand, it will affect heat treatment at the edge of the gear and be somewhat less strong, so if it breaks off it may lodge between other gears...........but if you don't have a good tooth to start with, it may also impede gear engagement and break and lodge between other gears.

If you are gonna granny shift it all the time, shouldn't be a problem if you go ahead and fix it. Me, I'd be looking for a 5 speed conversion.

 

You can weld most steels although very high carbon steels and tool steels are very difficult if not impossible. Brazing is not welding. It doesn't matter if you can weld it. What matters is what you end up with. That gear shaft was undoubtedly heat treated by a case hardening process most likely carburizing. The surface of the teeth are harder and more wear resistant than the material deeper down in the tooth (which is now exposed). You run the risk of even more damage when it fails whether you run it or attempt to repair it. Find a subs***ute and sleep good.

 

TomcatII is correct; to fix the problem correctly you'd have to add material to the damage area, work the welded area to the proper shape, then heat the gear to red hot before burying it in a carbon-rich material to "case harden" the gear teeth. It's possible but only a viable option when no better replacement parts can be sourced. In other words, get busy and find a replacement part.

 

Home grown hardening appeals to me. Ice, wet, or dry.

 

Is the ‘39!a one year only thing? I thought I recalled @Mac VP saying the ‘39 - up boxes all used the same gears?
But as mentioned before, I’d contact him for parts if you haven’t.
I had the back gear on my lathe repaired as well, pinned and brazed in, but that gear Im sure, wouldn’t see the load a vehicle gear would.

 

All great, but years before me someone installed a 36-38 ? gear set into this nice 39 trans case. The cluster is unique in that sense, and I found a few NOS gears and parts for near nothing while doing my research on it. A. T-5 would obviously be great, but I was trying to use what I already had , and besides that I would need an adapter and other parts plus shortening the drive shaft and torque tube.... all of which will total to much more $$$ than fixing this.
If a later model side shift will interchange to this 39 case, then what am I looking for - years and models?
I've seen many advertised for lots less, but I'm not versed in what will transplant onto what. Go ahead and school me on this one thanks

 

Lets make a mountain out of a mole hill, or not.. Do as 6sally6 suggested and since the crashing [chipping] is going into first from neutral or 2nd gear; learn to double clutch when downshifting from 2nd and allow a second or two for gears to spin down some with the clutch released going from neutral into first.

 

I can’t lift the teachers pencil. I’d contact Mac.

 

I´m ashamed to admit it in public but I´ve reused a worse than that cluster in my 55 Chevy 3 speed OD transmission.... I just smoothed out the rough spots with a file and after that polished it some with fine sandpaper. It runs quietly and shifts smoothly behind the 235 and has been doing so for more than 30 k miles. Your cluster gear has plenty of meat ( and good teeth) left so I doubt that flatty in front of it makes enough ooomph to break it off and wreck any havoc... but than I´m just a hairdresser, not an engineer. I promised myself not to tell anyone, but ... oh well
Almost all the teeth looked like this or worse...I´m going to make it right someday, probably........not

 

Isn't it ironic....we're talking about..... HARDNESS.... and the name of your lathe is..."Rockwell"!
It's just kinda funny..."not Ha-Ha funny....just funny-funny".
6sally6