Saving a 3112V (rear end)

[Up-north55709 1]

Hi guys, I am trying to fix up a 3112V I picked up and I found a tough one. Bad news.... Cracked axle tube on the right (diff) side. Sounds like this may be a somewhat common issue, any recommendations on repair/replacement? I am going to chat with a machinist friend of mine this week. I do have a B-112 parts tractor (not sure on the condition of the transmission though).I figured nothing can be done with it in the transmission, so I took it apart to remove the tube. Everything else is in great shape, barely any wear!If I get the tube fixed/replaced, anyone know what/where I can get a T-gasket (simplicity pn 2154270). I get a lot of "no longer available". Side note, anyone know what causes the crack?Thanks in advance!

[Up-north55709 1]

Hard to tell from the pic, but it is cracked along the inside edge of the key slot, from the end to about half way to the case.

[Bill725 1,177]

My cracked at the keyway inside the transmission and ran to the outside of the case. I bought a new axle tube. Try RTV instead of a gasket but you will have to check the side clearance before final assembly and may have to remove a shim the same thickness as the original gasket.

[Up-north55709 1]

Thanks Bill, I assumed it was a design flaw with the inner keyway lined up with the outer keyway (seems to create an un-necessary weak point between the two).

Know of anywhere I can get a new tube? Another NLA...

I thought about doing RTV for the gasket, but was worried about the clearance issue...? Anyone else do this, if so, any idea what that clearance is (and tolerance?)

[720nut 4,225]

Why not just make the gasket, I'm sure everyone has a time or two.

[Bill725 1,177]

Axle tube NLA? Really. If so, I would have a machine shop make one. Not that much machining. If I remember (2) keyways (1 for gear inside case & 1 for differential), ring groove, drill & tap for grease fitting & ream the ends for bronze bushings. Check the keyway in the end of the axle shaft.

[Up-north55709 1]

Im going to search a little more for a replacement Axle tube, see what I can find. Spoke briefly with a machinist and he figured it would be quite costly to fix this one or make a new one. If I cant find a new one, figure I will try tearing the rear end of my B-112 parts tractor apart...

As for the gasket, I figure I can make one, just worried about clearance issues?? Should I be?

[Up-north55709 1]

Update:

Apparently the axle tube has a new number (that few dealers knew about) : 2164222SM (this was given by the partstore tech dept).

Most places charge between $180-$230 for this tube. OUCH.

The transmission gasket is superceded by p/n 2164234SM (also available most places $13-16)

[dhoadley 1,747]

Good to know

[1978Simplicity7016H 39]

Yep my dad is a dealer and we compltely re-built my B-10's transmission. If you can find the superceeded part numbers usually Simplicity will have them in stock.

Yes, the axle tubes are expensive. Better than finding a used one and then have it crack as soon as you put it all back together and test it.

[Up-north55709 1]

True statement Daniel.

I also found a guy on another thread that dealt with this same issue, and placed a muffler clamp on the tube. He replaced the cracked tube with a used one (not cracked), and has had many years of heavy use without any issue. Sounds like a simple fix... I will check out my parts tractor tube, hopefully it is in good shape.

[1978Simplicity7016H 39]

I found this thread VERY helpful about axle tube failure.

http://www.simpletractors.com/club2/topic.asp?TOPIC_ID=124147

Reading HubbardRA'sid="blue"> reply will tell you exactly why these tubes crack.

I have cracked two in my lifetime. One I will admit was my fault. It was in reverse and I forced it into forward, didn't go foreward. (I will never do that again)

The other one was a worn out shuttle in 1st going up a hill hauling a 48" deck in a wagon. Made it up the hill, but after that I noticed it was cracked. It had many hours on it so I wasn't surprised.

As long as you aren't hard on them with sudden movements they will last. I have seen people put a LOT of pressure on them before!

[Up-north55709 1]

Awesome. Thanks Daniel! That is very helpful. I tried searching the forums for that type of info before I posted, but I guess I didnt dig deep enough.

I hope the parts tractor tube is in decent shape, I will use that one, put a clamp on it, and let it ride. I dont do much with this old timer (yet?), so I will take it easy on her and let it ride!

[1978Simplicity7016H 39]

Your welcome!

You can work these tractors, but just remember they weren't made to be used as bulldozers.

[MikeES 458]

The muffler clamp is an idea I came up with to save the right side case when the tube fails, during pulling. It will not prevent an axle tube from cracking or splitting. It is usually caused by what HubbardRA explained and or worn keys that get rounded.Broke 2 axle tubes in 47 years. First was nephew doing wheelies with my HB212 (hydro in reverse to full forward). Second was 4th pull with pulling tractor ACE, split and broke the right side case also. After a full rebuild with very tight keys, did not break a tube again with 2 pulling tractors.

[Bill725 1,177]

When reassembling, make sure to place a plastic bag over the end of the axle tube before you slide the transmission case cover over it or the keyways and ring groove will cut the axle tube seal.

[Bill725 1,177]

The failure is due to material fatigue caused by several cycles of acceleration & deceleration forces/reversing torque due to starting and stopping. The crack starts at the stress riser at the bottom of the keyway. With continued use the crack will propagate. In my case, the crack started at the keyway inside the transmission and propagated out past the bearing and seal to the outside of the transmission. The telltale sign something was wrong was when I noticed all the transmission fluid leaked out on the floor.

[Up-north55709 1]

Still in progress, have to take the parts tractor apart and find out if the tube is any good before spending the $200 on a new one. Thanks guys for all the info, super helpful!

[Up-north55709 1]

Also good to note, the t gasket and seals were available to order through my local fleet supply (L and M supply), they were slightly cheaper and no cost for shipping (pick up in store). Took about 5 days. (They can also order the axle tube for same price as others, again free shipping).