cockshutt 30/e3 differential swap

OK so ill try to make this easy to understand, I have a bad ring and pinion on my E3 so I purchased a parts tractor that is a few years older (not sure on exact, frame was too rusted to read numbers) Mine is a 1950 SN 26,843 which should put it at a 1950, it has open steel brakes at 2-5/8 wide. The parts one I'm assuming to be a 46-47 with the closed brake system.

after swapping the ring and pinion and bull drives I found that the bull drives are too small in diameter, so my brake drums don't go on all the way without hitting the bolts behind them that hold the flange. I dry fitted my Original bull drives and they fit but hit the back of the ring gear barely due to the design.

All in all it looks like I just cant use a mix of old or new, but also cant use the band/enclosed brake bull drives/ring/pinion with my newer open shoe type.

My question is. There is a guy in MI who has generously offered me parts at a fair price, His aret he open type, but the narrower steel (not cast) brakes... If I get his whole setup will that work in my tractor WITH THE FACT that I just need to order narrower brake shoes?




this is the one I installed from the parts tractor, see how it has the ribs cast into it, the bull pinion shafts just barely touch the castings.

Notice the depth difference, the one on the right is the original, the one on the left is from the loaner and went with the ring with the castings in it. the only other difference is the end that the brakes go on is about 1/8" larger in diameter with the threaded hole also slightly larger.

this is the original, see how its deeper and smooth.

sorry for so many posts, Im not sure how to use the photo add, the first one was by luck and it wouldn't work from there.

So with that said, what recommendations do you have? I thought about just grinding a little of the casting away, BUT my bull pinions are bad anyway (chipped teeth) So until I find the correct parts I don't want to do any modifying.

There is a break at serial number 27689 and different thrust washers were used to set the thrust. If you use the washers that are with the doner it should work. Try to get a parts manual that shows both set ups, it only shows one differential gear. The one I looked at is from a 1955 parts book. See if you can check the backlash in the bearing which should be in the service manual. I hope this helps

Chris, I tried to help you once before but you seemed to move on to others. You seem to be getting into a mess so I will try again. At ser# 10000 they changed tranni/rear end casings and was the first change in brakes. That was mid 1948. then there was bigger changes in mid 1950 at ser# 27689 which included the differential, brake pinions, bull gears, brakes again and some other pieces. There were some other changes at ser# 36240. Needless to say most of these parts you are working with are not interchangeable. Long story short you need parts from the same ser# ranges.

(quoted from post at 17:52:34 04/16/14) Chris, I tried to help you once before but you seemed to move on to others. You seem to be getting into a mess so I will try again. At ser# 10000 they changed tranni/rear end casings and was the first change in brakes. That was mid 1948. then there was bigger changes in mid 1950 at ser# 27689 which included the differential, brake pinions, bull gears, brakes again and some other pieces. There were some other changes at ser# 36240. Needless to say most of these parts you are working with are not interchangeable. Long story short you need parts from the same ser# ranges.

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I will give this new one I bought a try, it's just a bit newer than the 27689 but all measurements seem correct. And mine is just a bit older, i got the whole trans and cast case, minus bull gear and axle tubes. So basically if new be I will use the newer housing, trans, ring, pinion, planetary, and bull pinion shafts. And use my older (but same year) axle tubes and bull gears.... Will let everyone know how it works, irv I'm not sure which time I spoke to you and appreciate the help, but I've ha lots of folks say that they could get me parts or help me, or they stock them only to not give me a price or answer the phone. Not sure if it was you or not and mean no harm. I'm just wanting to get this straightened out. It's costing me a lot of money and time, did 475 miles today to get some parts and would be upset if they were not good.

The one I picke up today was 27,7xx so I hope that it will work, mine is 26,84x
I do know, the bull pinion shafts are correct, and the whole assembly is there. Fingers crossed

So far things are looking good, I do need to use the complete pinion, ring, planetary, bull pinion, and large brake keeper screws. Looks like the only difference is the shaft that the ring gear rides on is longer and therefore needs the shorter nuts. I may end up driving it out and using my original ring shaft and bull pinion bolts. But again I'm not so sure why I would go through the trouble.

Irv, do you sell parts? I can't get Phil to respond and I'm ready to move forward. I am going to need some engine parts soon (complete piston/cylinder/ring kit, main bearings, ect. Maybe valve guides, cam bearings and a few other odds an ends.