520-H Pulling hydro Problem Help

[Dennis 0]

Hello

This is my first post here. I have a Wheel Horse 520-H garden tractor that I purchased new in 1989. It's been a great mower and overworked on many occasions and approaching 1000 hours. I'm having a problem (I think)with the Hydrostat. Whenever I get the tractor on a relatively steep incline or in a heavy strain it shutter and jumps and produces a grinding sound and stops pulling. I'm also getting a hydro over temp warning light. It has fresh oil and filter. If necessary I can rebuild the pump but if there is something I can do that can get me through the mowing season I would appreciate any tips. I need a good source for the rebuild kit if need be. Thanks, Dennis

[nylyon-(Admin) 7,120]

Hi Dennis and welcome to RedSquare. A couple of questions. Did the temp light come on at the same time which the rear started to make noise? Here are my thoughts which may or may not be correct

1. I know on my 416-H grass will collect all around the hydro unit and needs to get cleaned off all the time. Be sure that the pump is cleared of all debris. You may need to remove the seat and fender to get it all.

2. Did you use a Wheel Horse hydro filter? Some cross referenced filters may have a bypass valve which a Toro filter does not.

3. Check the axle hubs to see if perhaps the woodruff key is sheared. If the rear axle is spinning inside the hub, you will lose power and it would probably make a bad noise.

If none of the above, you may want to use caution on using the hydro until you it is diagnosed. You don't want to do more damage, these hydros are really expensive to repair.

Again and I hope this gets resolved quickly.

edit: I moved this topic to the Wheel Horse main area.

[Dennis 0]

Hi Karl

Thanks for the welcome and reply. The hydro temp warning has been coming on for a while now (months) after an hour or so running. I'd stop to let it cool then mow some more. The pump fins are clean and the cooling fan is operating properly. The filter is Toro/Wheel Horse from the local dealer and I'm using 10-w30 oil in the transaxle/pump. It feels like the fluid is bypassing in the pump. On level ground it seems fine but when it gets in a strain it acts up . Is there a rebuild kit available? Dennis

[nylyon-(Admin) 7,120]

Before looking into a rebuild kit, you will want to check the keyway in the rear axles. It is not uncommon to break the woodruff key, and the cost is less than $2.00. An easy way to test this would be to mark the hub and axle with marker, hilighter or what have you, then when you hear the noise, stop and see if the parts are still aligned.

You can also try to pull the hubs off and check that way, but sometimes the hubs will be seized onto the shafts, in that case it is probably not slipping. I don't know of any rebuild kits for these, but check the links section, there are some shops which specialize in these items. Again, hydro work can be quite costly > $1000.00 so check the simple stuff first.

[illinilefttackle 399]

:WRS: Dennis-Welcome- I also have a Hydro-so I feel your agony. Beautiful pieces of machinery until they cause you grief-One obvious question-sometimes its hard to notice it-but- is your drive belt slipping slightly? It can cause over heating, loss of power, and the stuttering you mentioned-When I got my horse, the belt was streched just enough to cause problems.

Karl had good advice-check it all if you can.-AL :whistle:

[kj4kicks 151]

Hi Dennis, and WELCOME !

I'll throw my 2 cents in the piggy bank here also.

When you mow, how much throttle are you giving it? You should be running around 3000 rpm's when working it.

Years of running it at low throttle may be taking it's toll on the hydro

They like to be run at the higher rpm's to assure pump pressure and flow. Anything less, and it oil starves the hydro.

Otherwise I would check the drive belt idler pulley, as well as the shaft that it is attached to (the one that goes through the frame). I have had several with about 1000 hours where the bushing was shot, and the shaft was worn out. For whatever reason, WH only used a bushing on the pulley side (where most of the load is), the left side only rides in the frame rail :imstupid:

[Dennis 0]

Thanks for the pointers. I'll check for the worn/broken key and belt slippage when I get home from work. I was hoping for some kind of additive that I could put in with the oil that would help A 1000, 00 bucks! Ouch. I hope that's not the case but if it is I can't replace the tractor for that and have anything worth having I guess.

[kj4kicks 151]

Dennis, Forgot to add this. At the risk of assuming anything, there should also be a tensioner spring on the drive belt pulley assembly. Make sure it's there / not broken or missing.

[kpinnc 10,718]

Dennis,

Eldon, Karl, and Al definately gave some good pointers for you to check on. If you find after looking it over, that it is the pump, don't get too upset about it. Yes, they are very expensive to repair. You'll probably be much better off looking for a replacement.

The 520H uses the Eaton 1100 series CCW pump, and they are also used in many other tractor manufactuer's machines. Ford, JD, Lawn Boy, etc... Point being, there are replacements available, even though Toro dosen't carry them anymore. The biggest thing you'll need to be sure of is that you find one with the same shaft type on both sides that your 520 uses. It's keyed on the input side, and splined on the output.

There are also a few companies on the internet that "refurb" the pumps. They will sell you a refurbed one for MUCH less than a new one, and take your shot pump as a trade in. They usually come with a warranty as well.

I have seen the Eaton 1100 series pumps sell new for around $450 online, but it was some time ago.

Point of all this being, they are still out there. You may have to look around a bit, but they are still available.

A 520H is an awesome machine, and if you find a good pump (if it becomes neccesary), you'll easily get another 1000 hours out of it!

Good luck!

Kevin

[Dual Wheels 2]

I don't know how far away you are from me but if it is practical and it ends up you need one, I have a complete pump and rear-end I just changed on a 520H. I know it works good, just needs cleaned up painted and new axle seals in it. The PO left it sit outside I had a new one here so rather than repairing it I replaced it. If you ar interested , let me know I live in Western Pa.... :whistle:

[Dennis 0]

Hey All

I just got the chance to check out everyone's suggestions. The main drive belt to the pump isn't slipping (dang it) that would have been an easy fix. All of the keys are ok. What I ended up doing was draining 3 quarts from the Transaxle and putting in straight 50 weight oil. The tractor now pulls the hills ok but still overheats.

I've come to the conclusion that if I can limp by this mowing season the way the horse is now; I'll put a new pump on over the winter. I'll also do an overall refurb while I'm at it.

The local Toro/Wheel Horse dealer told me that there are no rebuild kits available for the Eaton Model 11.

Also I was wrong about the hours. It's got 1441 Hrs on the tractor and around 300 on the engine.

I think maybe I should not hang around here (just kiddin) . I've caught myself looking at vintage horses on eBay. I'm kinda getting the itch to buy something to overhaul.

Kevin, could you send me the names of the refurb companies your mentioned in your post? Thanks :whistle:

[kpinnc 10,718]

Kevin, could you send me the names of the refurb companies your mentioned in your post? Thanks

I'll have to dig around a bit for it Dennis, and you may want to look online as well. The place I'm looking for took a "core" trade for a refurb pump. Since I had two bad pumps to trade, and refurbed one was only gonna cost me $160...

That was about 2 years ago...

I'll see if I can find some of the e-mails when I get home from work.

Kevin

[nylyon-(Admin) 7,120]

Check the links section, there is BJ Hydraulics, they do this kind of work.