Possible broken drive axle D grader

TramwayGuy - I have to say that I'm loathed to make any modifications to the new shaft. Given the age of the machine and the amount that I use it, my inclination is just to run it as it is. I have no doubt that it will give me a few years of work - which will be more than enough.

There is also the question of: if I fix that flaw where does the stress go to? The answer may well be: to the splines on the inboard end in the bevel gear (which I'm told is another common failure in these machines), which would be a much bigger problem to fix!  If I have to choose a failure point then I'd definitely rather it broke at the chain box end like this.  Call it "sacrificial"

I see your gear oil is in steel pails. Is that still common down under? Plastic pails are the common container any longer here.

So today was the day and I finally got to start putting the new drive shaft in the grader!

First job:drill a new drain hole at the back of the chain box because there was no way I was going to bail the remaining 15mm of oil out through the side hatch. That oil was nasty...

Drilling of a 10.8mm hole was followed by tapping and the installation of a sump plug with crush washer. Took me forever to find the right size drill bit (10.8mm - seriously? I had to buy that online couldn't find it anywhere on a shelf) 12mm (UNF I think) taps (which everyone had sold out of) and bungs to suit (which were thankfully easy enough to find), but it worked out really well - and the (horrible dirt laden) oil made the tapping pretty easy - free lubrication!

A side note here - when I was measuring up the chain box to work out where to put the drain hole it became apparent that Allis Chalmers A. weren't playing - those chain boxes are made of 12mm / half inch steel that my HS drill bits took their own sweet time getting through and B. did not care in the least how the result looked. The end plate is just slapped on there and welded in place. Alignment? Who cares? it won't matter once it's welded on!

Next step, clean out about four liters of oil, 3mm of mud, and - I kid you not - enough ball bearings, split pins, and shards of metal to make a disaster movie. Bad things happened in that chainbox somewhere in the past (yes that a little bit of foreshadowing). But it all cleaned up pretty nicely in the end - after repeated flushing with diesel (shaking the grader around to slosh the diesel was the hardest part), then lots of wiping out with cloth rags that went straight in the bin!

Looks rather nice in there now:

Next step: insert the new oil seal. I didn't have anything to press it in with, so I went for the "lump of wood hacked into a workable shape" option. It worked. I don't think that the seal suffered any real damage.

The eagle eyed among you will notice that something bad happened to the bearing seat in the photo above. Here's a better view:

I have no idea what, but I'm guessing that it was involved in the installation of the scrap bin of metal parts and shards in the bottom of the chain box some time ago. Still, I think it just looks nasty and shouldn't effect anything. And yes I did clean out the bearing and snap ring seat before I proceeded.

Then it was time to pull out the new driveshaft:

Don't ask me how but the (phone) camera makes these two *identical* shafts look vastly different lengths. Thankfully they aren't and I have other photos to prove it - but look at that shiny new metal! Mmmmm... shiny.

Shaft went in nicely, then I pressed the bearing in.  Thankfully while firm, it wasn't nearly as tight a fit as the oil seal, so I managed to slowly, gently tap it in, again with appropriately hacked wood. I got it in flush with the housing, but ran out of time to shape another piece of wood to let me push it in further. But it's in place at least!

So, having run out of time I buttoned everything back up to keep the water out and called it a day.

I'll be back to it on Sunday hopefully. Get that bearing finished, install the snap ring (I have a bad feeling that is going to be a fight), install the centre sprocket, reinstall the chains, fill with oil, make up new gaskets for all of the chain box ports, then bolt the ports down.

Then I have to go de-sludge the other side... (at least I get to use my expensive, weird drill bit and expensive, rare taps again).

So more photos and narration will follow!

I have used a welder to WELD on the race.. This actually looks like they were trying to BURN the race in half.. Carbon arc.. or HIGH AMPS on that stick.

The rear sprocket on the same side was slightly loose on the tapered shaft. The washer and the nut were tight to the boss on the shaft but the wheel was still loose on the shaft. It had been this way since new so the taper and the keyway on the wheel had suffered some wear. Some spray welding and machining to the inner hole of the wheel match the taper of the axle made the wheel tight to the shaft. The keyway was machined and a new key was made that fit the keyway on the wheel one one side and the keyway on the axle on the other side. I had a cupped washer made so the nut could now push the wheel tightly on the shaft. New chains for that side and it was good to go. Spent a lot of money for this fix but never had any more problems with the wheels. Apparently some others had encountered similar problems with bad machining by AC.