R-400 differential broken gear terth

[R-400]

Hi, I'm a new member here from Ontario Canada. I have now experienced the dreaded loud cracking, popping sound for the second while owning this loader. The first time it happened I took it to Larken, a Kubota dealer in Markham Ontario and it ended up costing around $8,000.00 dollars to completely rebuild the differential. This time, being retired, I thought I'd see if I can repair it myself. I have just removed the differential from the loader and opened it up to find the worst case scenario. I attach pictures if I can figure out how.
I know parts are hard to find and expensive. My question is, from your point view, should I just disable the rear diff. and use the loader as a front wheel drive forklift and backhoe or proceed trying to find parts and do the repair.
Thanks for your input.
(Sorry if the picture is huge, couldn't see how to reduce the image size)

 

[R-400]

Should read "broken teeth" not sure how that happened lol

 

[Fedup]

Having never seen one of those machines, I know nothing about them. That said, I wonder if the ring and pinion was the initial failure in the first go around? If so, and it's torn up again, then I doubt the other drive axle will survive for very long as the one and only source of power.

As I see it, you take a bath either way. You spend the money to fix it again, or you lose money and basically give it away for whatever you can get for it. You take the guts out of the rear unit, run it with front drive only, and when that fails you have even less value left in it.

No good options here. You can save some on the repair if you do it yourself, provided you feel comfortable with making the proper adjustments when setting it up. As you know, it's not simply "bolt it together and you're done".

 

[Russell King]

Find a used rear axle to swap out completely?

 

[R-400]

Having never seen one of those machines, I know nothing about them. That said, I wonder if the ring and pinion was the initial failure in the first go around? If so, and it's torn up again, then I doubt the other drive axle will survive for very long as the one and only source of power.

As I see it, you take a bath either way. You spend the money to fix it again, or you lose money and basically give it away for whatever you can get for it. You take the guts out of the rear unit, run it with front drive only, and when that fails you have even less value left in it.

No good options here. You can save some on the repair if you do it yourself, provided you feel comfortable with making the proper adjustments when setting it up. As you know, it's not simply "bolt it together and you're done".

Yes, I agree, however if it's front wheel drive there isn't going to be any heavy pushing anymore it will be for transport only, I figure it should be good for a while.
I have attached a picture of the old girl.

 

[R-400]

Find a used rear axle to swap out completely?

Unfortunately there are already people looking for them with no success. It was a flawed design.

 

[Fedup]

Yes, I agree, however if it's front wheel drive there isn't going to be any heavy pushing anymore it will be for transport only, I figure it should be good for a while.
I have attached a picture of the old girl.
View attachment 86600

I agree you will no doubt be doubly cautious of it's limitations, but you're still operating with only half a drive train, even if you don't put much extra stress on it.

 

[mikester]

Bad gear or pinion not shimmed and torqued properly? How are your bearings and seals?

 

[Yooper]

I see a crack in the carrier casting where the pin for spider gears is. Pretty much seals the deal for trying to rebuild it. I would run it like you suggested and keep my eyes open for a used differential.

 

[R-400]

Bad gear or pinion not shimmed and torqued properly? How are your bearings and seals?

I think it was probably assembled properly, just too much torque for a weak diff. I only drove it for about 2,000 feet after it broke so other than the pinion and spider gears showing some damage I think the axle bearings should be ok. Once I get the pinion and a spider removed I'll check for smooth operation, I really don't want to disassemble everything unless it feels rough. The seals didn't leak when it sat for 3 days.

 

[R-400]

I see a crack in the carrier casting where the pin for spider gears is. Pretty much seals the deal for trying to rebuild it. I would run it like you suggested and keep my eyes open for a used differential.

That's the plan, as long as the backhoe is working it's still valuable to me, eagle eyes, lol