Clutch shaft spline repair

[3Lfarms]

I am replacing the clutch in my 36 Farmall F-20 and the clutch shaft splines are more than 50% worn away. The splines that the clutch disc rides are fine, the bad ones are the splines that a coupler slides on to connect to the trans. The yoke splines are undamaged and I suspect someone replaced the yoke the last time it was apart.
I want to repair the shaft, and I had a mechanical engineer friend (I’m an aircraft mechanic) look at it and he thinks I’ll be just fine TIG welding it to build up the splines and then turn it on the lathe to get it back to round and use the mill to remachine the splines.

My question is how do I best make use of the Bridgeport to clean up the splines? I am thinking I can just use a 7/32 end mill and table the thing back and forth. Is that going to work? I don’t really have access to the correct gear cutting machinery.
I am not a machinist, I just use the mill as a big drill press and the lathe for cutting spacers and simple stuff like that.
What should my spindle speed be? How much of a depth of cut is proper with a 7/32 end mill? Feed speed? Does it need cutting oil/fluid? This mill doesn’t have any cutting fluid in it as it’s a really old machine, all manual, with a DRO.
Thanks.

 

[flyerdan]

You could do that, but it would be time consuming. You might check with a machine shop with a horizontal saw and see if they can recut the splines once you've built them up. That's what they use to put key grooves and woodruff slots in shafts.
For cooling on the mill, there are aftermarket air siphon misters that work real good. Get the coolant in concentrate and mix yourself, like welding anti-spatter.

 

[WranglerX]

What is your time and material worth compared to just replacing shaft with new (if new available)...

Dale

 

[ruffdog]

Yes, a horizontal mill with a over arm attachment and a indexing head would be ideal for machining the spline. Speeds and feeds are determined by the cutting tool (HSS or carbide) and the metal being machined. Replacement parts are quite cheap so I would go that route.

 

[RNeumann]

Since you TIG and have a lathe I’d be inclined to make something that would cut one spline with a press and jig made with tool steel. This would be done after the TIG buildup on each spline.

Kinda like this......one spline at a time

Tips To Remove Weld From Tubing - YouTube

 

[3Lfarms]

I don’t really consider my time where this tractor is concerned. I’ve spent quite a lot on parts thus far already. I like to play with the TIG, lathe, and mill when I have the chance.
How long should I expect it to take me to mill it? I didn’t look to see whether the end mills were HSS or carbide.
I have silicon bronze TIG wire, is there any benefit to using that? I would think that would mill easier.

 

[ruffdog]

Some bronze is **** hard. As far as welding goes, you have to know how your filler rod reacts with the base metal. Sometimes 2 soft metals make hard metal, like adding aluminum to brass.

 

[3Lfarms]

Using the silicon bronze wire is really just TIG brazing. It supposedly melts at lower temp. It makes using the TIG much easier than regular steel filler for jobs where max strength isn’t required. I bought some and put my welder cart together with it after watching Jody do it. I was able to make it look pretty darn good using that stuff.

 

[ptsg]

Build the splines up with TIG, then put the shaft on the lathe and turn the diameter. Then just take it to the mill, find a good way to index it (preferably using the original splines if there is a portion without wear) and cut it with an end mill.

Take your time. Maybe leave a bit of material left so you can hand fit it with a file.

If anything goes wrong, just build it up again and try again.

I've made a PTO shaft on a Bridgeport mill before without indexing head nor the proper cutter for it. Heck, it came out perfect and absolutely no play at all.

 

[yomax4]

I'm not a machinest at all. But I do know a little about filler metals and I'd say google Aluminum Bronze Tig or Nickel Silver Brazing as opposed to Silicon bronze for this repair. SIb is great but there are other options. I've done a lot of ATV ring and pinions with both. Good luck !!