Jump to content

Unofficial Home of Old Simplicity & Allis-Chalmers Garden Tractors

JohnInin

99 simplicity sovereign hydro

Recommended Posts

JohnInin

Hello,  halfway through mowing my yard a month ago, my sovereign lost forward movement. It would move in reverse but with some screeching involved.  I talked to a mechanic, he recommended switching the check valves to see if it reversed the problem.  I removed them and seeing nothing obviously damaged, I switched and reinstalled them.  This did not change anything, still a little reverse and no forward.  Checking the parts websites, few parts are available.  I have already come to terms that it may not be salvageable and time to get what I can out of it.  I know I could get more with the hydro working but no sense in sinking a grand in it if that is what it is worth.  It would make an excellent parts tractor as the engine, deck, tiller, etc are all in very good shape.  I paid about 9k for it 20-some years ago and it has been a dependable machine… up until now.  I originally purchased it to mow my Grandma’s 3 acres and till her garden patch for her.  She passed about 4 years later at 90 and since then, I’ve been using it on my half acre suburban yard.

I am open to info, ideas or suggestions as far as possibility of fixing current hydro… finding a used working hydro… selling it as is… or parting it out.

Many thanks, John.

Share this post


Link to post
Share on other sites
CarlH

Should be a lot of good used Sundstrand hydrostat units available.  They are generally pretty durable.  Might want to raise the rearend and make sure the problem isn't in the Peerless transmission.

 

  • Like 1

Share this post


Link to post
Share on other sites
CarlH

Jack both rear wheels off the ground with the front wheels securely blocked.  Start the engine and move the hydro neutral, forward, and reverse to determine where the unpleasant noise originates.  Both transmissions and hydro's are readily available if you are interested in turning wrenches.

  • Like 1

Share this post


Link to post
Share on other sites
SmilinSam

Did you check the basics?  IE fluid level,  belt tension, control linkage tightness....

  • Like 1

Share this post


Link to post
Share on other sites
Brettw
Posted (edited)

I agree with fluid and filter first.  I would be surprised if the Sundstrand failed, they are for the most part, bulletproof.  I would suspect the movement issues to be in the transaxle or keys and keyways before the Sundstrand pump.  And before I would bail on that late model Sovereign, I would also agree with the above.  Pumps, transaxles and complete rear ends are available and not too expensive or difficult to change out if you have any mechanical inclination.  Good luck!

Edited by Brettw
  • Like 1

Share this post


Link to post
Share on other sites
JohnInin

Okay, boys.  The fluid is full and the belt is tight.  I will admit to not remembering when I last changed the filter, though.

I jacked up the rear end and using a mechanic’s stethoscope, the screeching is definitely coming from the hydro and not the tranny.  With the engine off, I can spin the right tire and the left turns opposite.  Spinning the right tire yields the same but there is about a quarter turn before the left wheel “catches“.  Correct me if I’m wrong, but this also leads me to believe the tranny is in better shape than the hydro?  Any other ideas for a easy, cheap fix?

Full disclosure time… last year I push mowed for a month while tearing apart and diagnosing a sheared key in the bevel gear box so my wife is “strongly recommending” that I retire and replace it with a small rider and a walk behind tiller.  I’m tending to agree with her as it’s getting to be more of a pain at my age to swap out the deck and tiller come garden time.

How much would I be looking at for a complete rear end?  I did some checking and the sovereigns seem to be going anywhere from $1000 to $1500 asking price.  I assume that’s running condition but without a tiller.  I can wrench but I figure the cost to replace will be at least half of what I can get out of it.  How much is it worth to someone willing to part it out?

Again, thank you everyone for the replies so far and any more advice still welcome!  Mechanical or otherwise.

John.

PS  strap on seat is only for bypassing switch.

E83BA85C-8791-4D4A-8AF4-6C3E4E13D5C9.jpeg

71B4374F-8237-4CFA-8207-AE7011E76876.jpeg

Share this post


Link to post
Share on other sites
PhanDad

The reason for the "filter" question was if a new filter with "better" filtration characteristics (finer micron), is installed, the fluid flow will be restricted since the filter is on the suction side.  This can cause movement issues.

But based on your stethoscope examination the problem must be in the hydro pump/motor.  I believe they can be rebuilt but I would think it would be very expensive.  Many "parts" tractors have good Sundstrand hydro rear ends that can be swapped in.  Or you can buy just a good hydro unit such as this one:

https://www.ebay.com/itm/175039806145?hash=item28c12f7ac1:g:5HoAAOSwEoth6hk-

If you swap in either a whole rear end or just the hydro, you'll need to check if the hydro tractor had a hydraulic lift or not.  If it didn't have the hydraulic lift, you'll have to swap in the RVs from your tractor.  There are posts here describing the process.  

You have a late model Command powered PS Sovereign, a desirable tractor.  IMO, even if you decide to "downsize", it would be worth getting the tractor running before you would sell the package.  

 

  • Like 1

Share this post


Link to post
Share on other sites
PhanDad

Also if the replacement tranny is older, it might not have the side mount filter.  So you would need to use the "between the side plates" remote filter or convert it as described by @Brettw:

https://simpletractors.com/forums/topic/58385-filter-position-swap-on-a-sundstrand-update-and-pics/?tab=comments#comment-467702

And here's a few other posts to read by @Brettw about the Sundstrand hydros:  

https://simpletractors.com/forums/topic/58377-how-to-kill-a-sundstrand-hydro/

https://simpletractors.com/forums/topic/50200-dead-sundstrand-update/

 

  • Like 1

Share this post


Link to post
Share on other sites
Bill725
1 hour ago, JohnInin said:

it’s getting to be more of a pain at my age to swap out the deck and tiller come garden time.

That is exactly the excuse I used to purchase a second Sovereign. One for mowing and the second for tilling and snow blowing.

"Will trade wife for garden tractor!"

  • Like 4
  • Haha 1

Share this post


Link to post
Share on other sites
JohnInin

The “How to kill a sunstrand” topic link got me thinking….  What is the possibility of the drive gear between the hydro and tranny being my problem?  About 15 years ago, mowing around my pond’s incline one way was fine but the other way was a no go.  I can’t remember how/where I opened it up to find the problem but the bolt that held that gear in place came loose enough that it would stay engaged while tilting one direction around the pond but disengage tilting the other direction.  I remember putting red loc-tite on the bolt before tightening it back down.  Would this being loose again somehow cause the “some reverse and no forward” happening now?  And if so, remind me how I got to that gear.  I sure don’t remember removing the hydro!

Share this post


Link to post
Share on other sites
PhanDad
Posted (edited)
5 hours ago, JohnInin said:

...remind me how I got to that gear.  I sure don’t remember removing the hydro!

That's the only way to get to the gear (unless you split the tranny and remove the gears to get to it.  

First remove the two hydraulic hoses from the top left side of the hydro unit and the bottom hose to the tranny.

Then I use a harmonic damper puller to remove the pulley using the holes that attach the fan.  It it doesn't want to move, I use a pickle fork behind the pulley for some additional force:

  IMG_0155a.JPG.038a25f1dd85724e1ab9ec958b5ae274.JPG

Note: The above pic is for a Vickers hydro, but the drive pulley is the same.  

Then remove the bolts that hold the hydro to the tranny, I think there are 3 bolts, 2 on the back side and one on the front side of the hydro unit (circled in red):

IMG_4787b.jpg.4fa8623cba6e2cccb186add4c68a1e3e.jpg  

 

Edited by PhanDad
added last pic
  • Like 1

Share this post


Link to post
Share on other sites
PhanDad
7 minutes ago, JohnInin said:

Will do.  Does this sound like it could likely be causing my issue?

thanks! - john

I think it's possible. 

I'd like to hear opinions from @Brettw and others that have more Sundstrand hydro experience than I.  

 

Share this post


Link to post
Share on other sites
Brettw

One thing I recall about the bolt/lock washer/washer is that, yes, it did fall off, but the gear did not.  I don't think there was room for it to fall off the end of the shaft.  And the gear and shaft are spliced, there is no key or keyway to fail.  The only thing that caused me to find the problem at the time, was a deep dive into everything because of metal shavings in the fluid. (that is NEVER a good thing and could NOT be ignored).  Perhaps before you dive into disassembling the rear end, what makes you think the gear has fallen off?  Looking at your post in more detail, I can say unequivocally, that if the gear fell off, it's not moving in either forward or reverse.  My thinking is, something else is going on here.

  • Like 2

Share this post


Link to post
Share on other sites
JohnInin

Brettw

Just considering it because of how it acted when it did come loose.  It was loose enough to disengage depending on which way the tractor was tilted going around the pond.  I agree the gear can not come completely off the spline.  Plus, all the comments on how bullet proof the sunstrand is gives me hope it may be an easier fix.

Too hot to do anything now.  Probably take a closer look Saturday morning.

Share this post


Link to post
Share on other sites
CarlH
4 hours ago, JohnInin said:

 It was loose enough to disengage depending on which way the tractor was tilted going around the pond.

Might also want to check that the (4) bolts fastening the front frame to the BGB are tight.

  • Like 2

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


×