Broken Drive Shaft - Design Flaw Warning!!

[Klorinth]

Morning All,

So my T2334 drive shaft from the engine to the HST has broken... No drive shaft means she sits in the pasture unable to move.

After a bit of searching I found multiple discussions in the TYM forum about this problem. According to them it is a flaw in the design of the shaft. TYM has upgraded the shaft twice to correct the problem. The shaft now uses U-Joints because of the slight angle from the engine to the HST which adds extra strain on the shaft/HST connection. Sounds like it is the splines that eventually break which can lead to a very expensive repair to replace the HST stub.

I will try to get a few pictures once I take the shaft out. It is going to be ackward to do though. May require cutting a hole in the floor. Or cutting the shaft in half.

Anyone have suggestions on where I might get a new shaft???

 

[milligjg]

Might try these folks. They have a pretty good inventory of Montana parts.

Diamond R Equipment available in Missouri » Diamond R Equipment

 

[Klorinth]

Diamond R said they have one they can ship.

So I opened up the tractor and pulled out the shaft. The snap rings were a real pain to get off. Took longer to do that then anything else. Hate those things.

Cut hole in the floor.

Remove snap rings.

Pop out the ball bearings.

Slide the spline sleeves back and out it comes.

So it looks like the rough start was causing the balls and splines to bang constantly. Half of the splines are worn off. Not broken. Prices of the shaft have broken against the ball bearings. The splines are worn only on the HST side not the engine side.

Very frustrating that this has happened.

 

[SPYDERLK]

Diamond R said they have one they can ship.

So I opened up the tractor and pulled out the shaft. The snap rings were a real pain to get off. Took longer to do that then anything else. Hate those things.

Cut hole in the floor.

Remove snap rings.

Pop out the ball bearings.

Slide the spline sleeves back and out it comes.

So it looks like the rough start was causing the balls and splines to bang constantly. Half of the splines are worn off. Not broken. Prices of the shaft have broken against the ball bearings. The splines are worn only on the HST side not the engine side.

Very frustrating that this has happened.

Youre either going to have to replace that trans input spline, or else do something very special to prevent any more of the motion that caused that wear. ... Preferably both.

 

[timbatrader]

I am no expert so I would get a second opinion before following this advice
The spline that has worn is the one that has been sliding when there is movement between engine and HST you might get a bit more life out of that spline if you locked it up with plastic metal/locktight etc as long as you allowed the spline at the other end to take up the movement There are some very good speciality lubes available for the spline that you allow to move I have chopped out lots of splines on my Yamaha ATV regular lube with the right lube has extend the life of the splines compared to assembled dry or even using standard grease

 

[Bud Soda]

Your splines are just fine. The new shaft can slide up farther than than the old one and it is held tight to the output shaft with locking bolts on both ends. The two bolts don't come with the shaft but can be picked up at a auto parts store.

 

[SPYDERLK]

Your splines are just fine. The new shaft can slide up farther than than the old one and it is held tight to the output shaft with locking bolts on both ends. The two bolts don't come with the shaft but can be picked up at a auto parts store.

Thats trans input. Reduced wear area ... wobble issue ... much faster 2nd failure.

 

[Bud Soda]

Thats trans input. Reduced wear area ... wobble issue ... much faster 2nd failure.

The old shaft would wobble as it was loose on the trans shaft and the pump shaft. The new design clamps tight on both ends and does not slide or wobble.

 

[SPYDERLK]

The old shaft would wobble as it was loose on the trans shaft and the pump shaft. The new design clamps tight on both ends and does not slide or wobble.

Sounds good. Is the engine mounted rigid wrt trans to preclude thrust issues?

 

[Bud Soda]

Sounds good. Is the engine mounted rigid wrt trans to preclude thrust issues?

No. These tractors have a lot of frame twist, but the new shaft has U-joints on both ends and it is made in two parts that slide together giving it about three inches of forward and backward motion. This is the way it should have been designed the first time.

 

[RickB]

The old shaft would wobble as it was loose on the trans shaft and the pump shaft. The new design clamps tight on both ends and does not slide or wobble.

In theory. I don't expect those worn splines to grip any kind of clamped yoke squarely, or last much longer than it takes for the check to clear.

 

[Klorinth]

In theory. I don't expect those worn splines to grip any kind of clamped yoke squarely, or last much longer than it takes for the check to clear.

Rick, you may be right. It may not last as long as the original. That is fine with me. Spending $250 and an hour of my time is much better then having the tractor hauled to a repair shop, split in half, and the input shaft replaced in addition to the front shaft.

I just wish I had heard about this issue sooner. I would taken the shaft off and checked it. There is discussion about this in the TYM forum but I rarely ever looked there. Hopefully Montana owners will see this and check theirs before the damage is done.

 

[Coyote machine]

Frame twist, that seems like a real problem in itself, not to mention the poorly designed shaft and it's method of connecting the engine to HST. It there some sort of center bearing, with housing to give additional support and alignment aside from the 2 u-joints?
Are there any current ideas on how to reduce frame twist?

 

[Bud Soda]

Frame twist, that seems like a real problem in itself, not to mention the poorly designed shaft and it's method of connecting the engine to HST. It there some sort of center bearing, with housing to give additional support and alignment aside from the 2 u-joints?
Are there any current ideas on how to reduce frame twist?

I repaired my frame twist problem. There is a post about it in the TYM forum( http://www.tractorbynet.com/forums/tym-owning-operating/299636-273-broken-frame.html). I got 700 hours out of the old shaft. The new shaft will last much longer. It is made like one on a chevy truck front x-fer case to front axle. It will outlast the rest of the tractor. Now the front driveshaft will give problems I am sure because it is built like the HST one.

 

[SPYDERLK]

Rick, you may be right. It may not last as long as the original. That is fine with me. Spending $250 and an hour of my time is much better then having the tractor hauled to a repair shop, split in half, and the input shaft replaced in addition to the front shaft.

I just wish I had heard about this issue sooner. I would taken the shaft off and checked it. There is discussion about this in the TYM forum but I rarely ever looked there. Hopefully Montana owners will see this and check theirs before the damage is done.

IF it will clamp tight on the worn part of the spline Id stay on that part so that the splines mate evenly. ... But I would use # 638 Loctite in that socket to worn spline fit to fill voids as you clamp, and stabilize. Clamp it tight. With no movement it should last "forever".
,,,larry