My R-80-820-830 differential fix

[WeirdDeere]

I've seen my problem posted on here by one other person (a few years ago) and I thought I'd post my fix for what MIGHT be a common differential problem in the R-830 series tractors.

I tore into the transmission of my 80 because the differential seemed to have WAY too much endplay. The large gear was obviously moving side to side, I measured at least .050



Instead of bad bearings, I found out that the diff gear was sliding on the shaft. It originally was a press fit against a collar on the shaft.

I talked to a few people and after considering things I realized that there isn't a LOT of torque going through the shaft and gear. The large gear will transfer all the torque to the small pinion gears. After thinking about this I got a local machinist to do some work for me, with lots of good thoughts from him too!

The shaft was machined with a keyway, 3/8 inch wide, and the length of the gear.

The gear was broached to match. This key will keep the gear spinning with the shaft.

Then the shaft was cut with a snap ring groove. The snap ring will keep the gear from sliding side to side, while held against the collar on the shaft. This snap ring is thin enough that it does not interfere with the side pinion gear.

Here's a general view of the shaft


The snap ring groove


The broached keyway in the gear


And the installed snap ring


After getting the shaft and gear assembled, the rest of the assembly of the diff continued as normal. The bearings were the hardest part!

I just started getting the diff back in the tractor, and still am getting the shims right, but I'm very confident in the fix! I hope this will help anybody else with this problem.

Oh.....

After all was done, he gave me the custom broach guide for the gear, maybe it will come in handy some day!


Brandon

 

[John Deere D]

Thanks for the Pics. Sir:

Bob..

 

[K Effective]

Curious, what type of tool is used to broach the groove inside the big gear? Here it would be series of files and a lot of praying...

 

[tim s]

Hard to believe that it wasn't keyed in the beginning...

 

[WeirdDeere]

That's what EVERYBODY said when I described it

 

[WeirdDeere]

It's actually a broach and a guide used together, similar to this set:

http://www.grizzly.com/products/Keyway-Broach-Sets-18-pc-HSS/G9774?utm_campaign=zPage

Obviously my shaft wasn't a common size and he had to make a custom guide, but then he used a standard broach and a press. Makes a very nice clean and centered keyway

 

[WeirdDeere]

You're welcome!

 

[tim s]

Here is how I made the differential in my 60C, I had to actually do away with the differential and make it solid, other wise when I would pull a steer clutch it would quit moving..I turned a solid piece out to make for a press fit, then heated the gear up to get it on, like you would for a starter gear.

 

[WeirdDeere]

Real nice work!

I was considering welding the gear and shaft together, but with one being steel and the other cast didn't seem likely it'd hold long, and then when it let go it would probably get ugly!

I had to heat my diff bearings on a grill to drop them on haha

Brandon