520H Trans Overheating

[BigR 3]

I recently purchase a 1993 520H and used it this weekend for the first time.  I was mowing with the bagger/vac attached to pickup the leaves and after 45 mins to an hour the forward speed started to noticeably slow down.  Not long after the hyrdo high temp light came on.  I let everything cool down for a while and check the fluids.  The trans oil looked very clean and didn't have any burnt order.  I did notice the trans could use a cleaning with some caked on oil and dirt from over the years.  However, I wouldn't consider it terribly dirty.  I have not taken a look at the cooling fan as of yet either.  (Not really sure where that is located.)  After it cooled I tried again and everything worked fine for a half hour and then the forward speed started to lag again.  The reverse never seemed to slow down, which I thought it was unusual.  Eventually the high temp light came on again and at that point I parked it for the day.  

I'm planning to take the seat pan and side covers off and pressure wash the trans to get all the caked on oil and dirt off.  I also want to find the cooling fan and see what condition that is in.  The guy I bought it from also had an extra hydro filter which I thought I could change too.

My main concern is the loss of forward speed when the oil gets hot, but not the reverse speed.  I'm hoping there isn't something mechanically wrong with the hydro motor.

If anyone has any ideas on what I should look for, or possible mechanical problems please let me know.

Thanks

[slammer302 2,154]

I would take the seat pan off and give it a good cleaning and that way you can inspect it better check the belt make sure it looks good and the fan should be on the right side connected to the pulley on the pump 

[WNYPCRepair 1,875]

The fan is behind the right wheel
 

[BigR 3]

I actually had the pan off this weekend to hook up the rear lift arm and cable assembly.  I looked around for the fan but didn't see it.  Hopefully it isn't missing.

Any idea why the forward speed would be effected but not the reverse??  I also was surprised that the forward speed (with cold hyrdo) wasn't as fast as my 416-8's in 3rd high.  I figured it would be at least the same.  

All of these signs are now getting me a little concerned.

[WNYPCRepair 1,875]

I actually had the pan off this weekend to hook up the rear lift arm and cable assembly.  I looked around for the fan but didn't see it.  Hopefully it isn't missing.

Any idea why the forward speed would be effected but not the reverse??  I also was surprised that the forward speed (with cold hyrdo) wasn't as fast as my 416-8's in 3rd high.  I figured it would be at least the same.  

All of these signs are now getting me a little concerned.

Unfortunately, no, I am not much of a mechanic, but someone will be along that is and can probably answer your question. 

 

If you look above the right tire, you should be able to see the fan. The attached picture is not the correct model, but the fan is in the same spot

 

[953 nut 51,532]

 One important consideration is that the engine RPMs need to be kept near wide open throttle when operating a Hydro, that allows the cooling fan to be most effective. By design you are flowing more oil in forward than in reverse, that is why you don't notice the speed change in reverse. 

[squonk 38,844]

Those fans break a lot. still available from Toro I believe.-

[shallowwatersailor 3,213]

I bought a C-145 in Spring that only had the hub of the fan! I didn't even use it until I replaced it. There is a correct direction to install it as well.  And just as Richard said, keep the revs up on a Hydro.

The belt may be slipping as well which could lead to more heat. I would replace the belt and look at the idler's condition.

If you search for the specifications in the Manual section, you can find the top speed of each tractor. The 520-H has taller rear tires so should be equal or greater than your 416-8.

Edited November 16, 2015 by shallowwatersailor

[DennisThornton 4,769]

Very little first hand here with hydros but I have read of the fan missing.  Broken, fallen off?  Don't know, but gone.

[rokon 64]

if you had the seat pan off and didn't see the fan, its missing.

[BigR 3]

Thanks everyone for your helpful ideas.  Last night I checked again and yep...the fan is gone.  Unfortunately the bolt sheared off too.  Time to get out the drill and easy outs!!

I did notice that the input shaft for the hydro motor is recessed into the pulley about 3/4".  Is that common or should I do some adjusting.  The belt that is on the tractor is brand new so I can't tell if it is wearing unevenly. I did not pull off the side cover yet to expose the full drive belt.  

If the pulley needs to stay at that location on the shaft, should I consider "shimming" out to the edge of the pulley with a spacer or bushing?  Or will the space behind the plastic fan be okay??

Also, while I'm at it I'm going to change the fluids in the trans since I already have the filter.  What is the capacity for this unit and is 10W-30 what most are using?  (Sorry I'm being lazy, I'm sure I can dig it up online some where, but I figured someone on here would know right away)

Thanks again for all the help!!

[shallowwatersailor 3,213]

Is the belt running true? The fan hub does have a recess, if nthat is what you are asking.

Here are two pictures of what it should look like. The part number is #108393. The one is a clear view but on my 417-A that I have not done any work on since getting it earlier this year.. The other is the new fan on the C-145. Notice the direction of the blades on the C-145. Leaves get everywhere this time of season!

[BigR 3]

Thanks John!!

The pictures really help.  I now see the washer is like a fender washer that puts the pressure on the pulley OD not he ID of the pulley.  From what I can tell the belt is running true. 

I just ordered the fan from my local Toro dealer and he said it should be in tomorrow.  Hopefully this will take care of the overheating issue, but I hope the previous owner didn't do to much damage already.    

[lynnmor 6,762]

You said that it would be pressure washed.  No way would I ever take a pressure washer to the trans, the seals will allow water and dirt inside.  I pull the seat pan every year, after the leaf season, and clean with engine cleaner and a garden hose. Then I oil the moving parts as needed.

I have had the bolt holding the fan work loose.  Use some thread locker on that bolt.

Check the idler pulley and mounting hardware while you are in there.  I found a replacement pulley that didn't cost an arm and a leg like the Toro one.  I can't find the part number, but it was exactly the same and must have come from the same factory.  Hopefully someone can chime in with a source.

[shallowwatersailor 3,213]

Differing schools of thought on pressure washing. I wouldn't oil the linkage as oil attracts dirt.

I use Mobil 1 10W-30 Synthetic in my hydro tractors. I buy the 5 gallon jug as it will take 4.5 quarts in the 5xi and almost 5 quarts for the Classic Wheel Horse. Fill the filter about half full and install it loose. Then pour the oil and the air can escape by the filter. When it reaches that point, tighten the filter and slowly add the remainder. Some members loosen a bolt for air relief.

[WHX?? 46,693]

 guys  but I do pressure wash my horses but I have a pressure reg that I can dial down as needed. Why does a guy need to leave stuff loose like that John? Don't these trans.  bleed themselves out like hydraulics?  My new 520H is packed with crap in the hydro motor...will get it out though. 

Looks like that 417 needs a good cleaning John...want me to help?..?.OK I will send the Mrs over.....

[BigR 3]

To late on the pressure washing of the trans, I did it yesterday morning before you posted.  I'm not too concerned though, because the pressure washer was an electric style with not a lot of pressure.  Plus I'm going to replace the fluids and filter right away, so if anything did get in it should come out with the service.  Hopefully the new fan will be in today and I'll be running her through the paces this weekend.

[shallowwatersailor 3,213]

 Why does a guy need to leave stuff loose like that John? Don't these trans.  bleed themselves out like hydraulics?  My new 520H is packed with crap in the hydro motor...will get it out though. 

Looks like that 417 needs a good cleaning John...want me to help?..?.OK I will send the Mrs over.....

There are different methods for "burping" the Eaton 11 when doing a fluid change. It is a slow process unless you use one of the different methods to speed it up.

Some members put a small hose down the middle of the fill tube. Others remove one of the bolts into the trans (I never figured that one out.) I just leave the filter loose by a couple of threads and then tighten it when the oil gets to that point. It slow for the last bit then. After running it for a while, it is a good idea to let it cool and check the level again.

The 417-A will be a project for next Summer.  This year I didn't accomplish as much as I had planned.

[Duramax7man7 505]

Good reading so far as always on this site. Just wanted to put my 2 cents in on the bolt to loosen on top of the trans. 

 I figured out that the bolt to remove is the rear lift cable conduit brace bolt. Remove that bolt and fluid pours in like your filling a canyon. Perfect! Just make sure not to get anything in that hole and into the trans. It's probably best to clean that are well first by wiping of any dirt or using air pressure to blow out that area then proceed.

 

 Good Luck.

 P.S. I noticed that after filling my case (the axle seals were both leaking and I replaced them) that after a couple of short runs around the lot that if it sits for a few days, I have to increase the RPMs after initially starting and letting warm up before the tractor will move forward. Do I need to put more fluid in or is this normal for the trans to need to build up pressure first.

[Jerry77 1,218]

Manual calls for 10w30 motor oil.....I remember someone saying that you might have some leaks if you use the synthetic on an older system.....figure WH knew what was needed - don't know why synthetic would be better..

[Duramax7man7 505]

I always heard that using oil with detergents in older engines would cause leaks as it would clean sludge away from seals and allow seepage through weak areas. But all oils these days have detergents in them I thought.

 

And like others have said, synthetics are better especially at the end of the duration of oil change intervals and in cold weather.  

 Here is a video that I found a while ago explaining it.

 

[Jerry77 1,218]

18 minutes ago, Mastiffman said:

Here is a video that I found a while ago explaining it

Very interesting - thanks for sharing..

[Duramax7man7 505]

My pleasure.

[BESTDOGEVER 218]

Just a quick thought on pressure washing anything only use enough to do the job  (cleaning engine & parts  about 1000 psi)stay off seams &openings you should be okay did this professionally for 15 years and never tore up anything 

 

[Duramax7man7 505]

Yep I used a 1500psi pressure washer on my entire tractor with not a single adverse effect except removing flaking paint. ha ha.