It was good, until it stopped.

[SimpleMan]

Needing some help getting pointed in the right direction diagnosing a problem with my 1997 Sovereign.

Was moving a gravel pile using a homemade 'johnny bucket' and been at it for a few hours when I lost all drive, forward and back.  Prior to it happening I noticed a bit of lag (for lack of a better word) when I would move the hydro lever into forward, or reverse, but not noticing odd noises, paid no heed to it.  Shortly after that it all stopped moving.  Here's what I've noticed so far, and done:

- It is not locked up and I can push the tractor by hand.

- I have made doubly sure that the free wheeling lever was in 'drive' mode.

- With the back end off the ground and engine off when I rotate one tire by hand, the other moves in the same direction, at the same speed.

- The drive belt from the gearbox to hydrostatic pump is intact and rotates just fine.  There are no odd noises when the tractor is running, and the hydrostatic is in 'neutral'.  (Moving hydro lever forward or back results in nothing.)

- When I rotate the right tire back and forth there seems to be a lot of slop in the differential.  I have removed the differential for inspection and am wondering if anyone has had one of these apart.  What should I be looking for? 

- With the rear wheels off, and the differential assembly removed, I can easily rotate the axle tube by hand.

So, before I start tearing the entire back end of the tractor apart (something I hope I don't have to).  Does anyone have suggestions of things I should be looking into?

Thank you in advance for the responses.

 

 

[Brettw]

59 minutes ago, SimpleMan said:

- With the back end off the ground and engine off when I rotate one tire by hand, the other moves in the same direction, at the same speed.

This would make me believe it is likely a sheared axle key, or broken gears.  Generally there would be enough resistance from the driveline (even if the relief valves are activated) that when you turned one wheel, the differential would cause the other to turn in the opposite direction.  So it sounds like there is a disconnect from the pump/transaxle to the axle itself.  

[Tarheel]

 If it were mine, I believe I'd pull the pump and make sure the gear on the spline/d gear on the output shaft wasn't stripped. (The splines themselves more so than the gear teeth) May save the headache of taking down the whole rear.  It is something I have seen before.

[SimpleMan]

8 hours ago, Brettw said:

This would make me believe it is likely a sheared axle key, or broken gears.  Generally there would be enough resistance from the driveline (even if the relief valves are activated) that when you turned one wheel, the differential would cause the other to turn in the opposite direction.  So it sounds like there is a disconnect from the pump/transaxle to the axle itself.  

If I'm offered the choice, I'll take the sheared axle key.  Either way, does the transaxle have to come apart?

[SimpleMan]

3 hours ago, Tarheel said:

 If it were mine, I believe I'd pull the pump and make sure the gear on the spline/d gear on the output shaft wasn't stripped. (The splines themselves more so than the gear teeth) May save the headache of taking down the whole rear.  It is something I have seen before.

Good advice, and I may just look into this.

[PhanDad]

You may want to review this current post about a similar problem:

https://simpletractors.com/forums/topic/68752-help-t-16-gearbox-shift-lever-not-engaging/

Since it sounds like your issue is internal to the case, you should view the "axle tube replacement DIY" to see what might be happening inside the tranny case - final drive gear to axle tube keys, a common axle tube failure area.  The DIY is for a Vickers hydro, but the Sundstrand is similar (but doesn't have the removable left rear hub).   

These pics shows the suspected failure area:

 

[SimpleMan]

Pretty sure I found the culprit. Removed hydrostatic pump and found this gear loose and freewheeling on it's shaft.  Pretty sure it is not supposed to. (It meshes with the gear on the hydrostatic.)

Does it work to access the right side of the transmission to get at it without removing it from the tractor?

[PhanDad]

On 5/4/2024 at 11:19 AM, SimpleMan said:

Does it work to access the right side of the transmission to get at it without removing it from the tractor?

It's a lot easier to work on tranny on the bench.  But if you check out the axle tube replacement DIY post, even though it's a Vickers tranny, you'll get the idea of what's involved.

https://simpletractors.com/files/file/316-axle-tube-replacement-do-it-yourself/

 

[SimpleMan]

Heeded the advice and pulled the transmission. Thank you and glad I did.

Found the cause of all the grief. Key broke on the brake shaft causing the gear that meshes to the hydrostatic output gear to become loose. Does not appear to be any other major damage, that I can tell. 

Bought some key stock to make a new one.  Omce I have the repair complete I plan to reseal the transmission with rtv gasket maker instead of having to wait for weeks for the factory gasket. 

What  I am wondering is what is the correct 'sealer' to use when reinstalling the hydrostatic to the transmission.  Repair manual states to add a 1/8 inch bead of gasket eliminator on the transmission side and spraying the hydrostatic side with LocQuic primer NF.  Needing to know what these are so I purchase the right things.

[ShaunE]

Me personally, I would wait for the gasket. In addition, I was told by Simplicity Tech Support to use a specific Loc-Tite. 515 or 510. Can’t remember. The reason given to me was because the painting/e-coat finish was in the same building & there was an issue with any Silicone based sealer effecting the adhesion of the coating. I promise I’m not making this up.

As for the gasket eliminator, I use the Permatex Aviation gasket eliminator.

Edited May 9, 2024 by ShaunE

[PhanDad]

6 hours ago, SimpleMan said:

instead of having to wait for weeks for the factory gasket. 

sepw.com had the gasket in stock a couple of years ago; shipped it quickly.  

 

[Bill725]

11 hours ago, SimpleMan said:

Bought some key stock to make a new one.

FYI, the OEM key, P/N 2166014SM is a hi-profile key and still available. Not a standard square key.

[SimpleMan]

Took a while but got the workhorse up and running again. Thank you for all the advice, suggestions and support.

Oh, and as for my gravity defying tractor. I can't for the life of me figure out how to rotate it the correct way. (It is oriented correctly on my phone.)

[SimpleMan]