Jump to content
graywolf1939

How long should hydrostatic Xmission fluid last ?

Recommended Posts

graywolf1939

I have a 1988 H518 that has never had the hydrostatic transmission fluid changed. "Theoretically" I am told, it should never need changing. Well, we all know that brake fluid gets contaminated with moisture (water) and brake specialist/mechanics will tell you that they change the brake fluid every 3 years. So what makes Hydrostatic transmissions any different ? 33  years seems like far too long for this fluid to last in a tractor that is kept outside in a New England winter.

    Shifting has been very erratic, and slow, even though I have adjusted the transmission per owners manual with rear wheels jack up, etc etc.. Tonight, I ran the tractor after some maintenance, new tires, oil and filter change, new fuel lines and filter, and it ran Ok for about an hour, then just as I was about to stop, I could not shift the transmission at all, forward or reverse. So, I am going to drain and refill the hydraulic fluid before I go any further. Have any of you experienced similar behavior, or, have some words of wisdom on hydraulic oil ? Remember, 33 years same fluid.

 

Edited by graywolf1939
typo

Share this post


Link to post
Share on other sites
 
oliver2-44

Definitely time for a transmission oil and filter change.  While hydro's are less prone to get water in them,33 years is a long time for condensation to build up.  Since its stored outside, see what the fluid looks like.  If it looks black or worse milky grey/brown, it might be worth a 2nd change after its run a little while.   

If its been awhile since the center tin and seat tin has been pulled and the top of the hydro and and  the shift linkage cleaned, that would be a good place to start.  With the tins off verify the linkage moves smoothly with no slack/play in the connections. 

  • Like 1
  • Excellent 1

Share this post


Link to post
Share on other sites
 
gwest_ca

The North American 518-H got an Eaton 700 hydro with no external filter.

The exported models got the 1100 Eaton with external filter.

 

Garry

Share this post


Link to post
Share on other sites
 
peter lena

@oliver2-44 totally agree with you on your insight into that hydro oil change and its possible second change redo . that first change is years over do , and after the flushing action of new fluid , I  personally would keep an eye on it , and change it , due to disturbing, long varnished surfaces . would also detail all and every related linkage point with needed lubricant or enhancement for smooth action. pete  

Share this post


Link to post
Share on other sites
 
Handy Don

I'm not sure the manual writers for these anticipated 30+ years of use. But, given that it is such a gol-durned PITA to do on a 700 (the drain plug is practically inaccessible between the pump/motor and the transaxle), I'd opt for something like an every 6-8 years or 300-400 hours.

You can tell a lot from the condition of the oil in the expansion/reservoir tank (black screw off cap accessible under the seat). Use a clean, long-handle cotton swab to sample any sludge on the bottom of that tank and look carefully. If little or none and no metallic stuff, and you can still see through the oil, I'd say you are still good.

Edited by Handy Don

Share this post


Link to post
Share on other sites
 
shallowwatersailor

Change the transaxle fluid and put in fresh 10W-30. I would recommend synthetic motor oil which will run better. For the transmission pump, get a turkey baster and draw off as much as you can and refresh with 20W motor oil. Put a few hours of use on it and repeat. Repeat as many times as you feel is necessary.

  • Like 1

Share this post


Link to post
Share on other sites
 
graywolf1939

Thank you for the replies to all. When I got to checking out the problem this morning, I was met with the motion control rod out of it's hole in the side frame, the transmission drive pulley was off the rear pulley, the transmission fan had lost 3 of it's blades, and the transmission disengage rod was out of its hole in the lift control rod. Good Lord !! My guess is that when the motion control rod fell out of its hole in side frame, all the other damage was done.

 

Now the big problem guys !!! I ordered a new fan, but trying to get the old bolt off is not working too well. Seeing that the crank shaft is CCW rotation to drive the transmission and the fan, I am guessing that the screw is a CW removal as opposed to normal CCW removal like most threaded bolts ??? I have the bolt well lubricated for another crack at this in the morning. 

 

Is this cooling fan bolt a CW removal bolt ??

 

Thank you in advance guys 

Dick

Share this post


Link to post
Share on other sites
 
Handy Don
14 hours ago, graywolf1939 said:

Is this cooling fan bolt a CW removal bolt ??

Curious myself. Does the Eaton service manual give a hint?

Following.

Share this post


Link to post
Share on other sites
 
graywolf1939

I will have to research that Don, I was hoping that someone on the Forum had to change the fan and had first hand experience.

 

Share this post


Link to post
Share on other sites
 
gwest_ca

Should be a regular bolt.

If you held the bolt and turned the pulley CCW it would tighten the bolt.

So the natural direction of rotation will keep the bolt tight.

 

Garry

Share this post


Link to post
Share on other sites
 
Handy Don
15 minutes ago, graywolf1939 said:

I will have to research that Don, I was hoping that someone on the Forum had to change the fan and had first hand experience.

 

My 1100 manual IPL has this for the fan bolt:

Eslok Bolt 1/4-20 X 5/8

 

I'm pretty sure that if it was LH thread it would say so. It makes sense to me that it'd be RH thread, since the air resistance on the fan from the turning pulley would cause a RH thread to tighten

 

Edit: I see that @gwest_ca got here just ahead of me!

Edited by Handy Don

Share this post


Link to post
Share on other sites
 
mrc

i changed the fan on my fiends 312H (eaton 1100 equipped) quite awhile ago.  i do not remember anything out of the ordinary. so i'm saying it is a regular bolt.

best of luck

mike in mass.

Share this post


Link to post
Share on other sites
 
graywolf1939

I soaked the bolt with Kroil to help gets the threads lubricated. What Garry said makes sense to me also. The belt turns CCW, of that I am sure. So if the head of the bolt were held with a wrench and the belt were turned by hand in the CCW direction, the bolt would certainly tighten. The only thing that goes against this thinking is that once the bolt is tightened, and tractor is running, the belt of course is turning CCW, therefore if the bolt were to become loosened, it could back right out with enough time because there is nothing holding the bolt head itself. I am going to try backing the screw out turning it CCW, standard removal direction for 99.9% of bolts, and post my results here on the Forum for info for all to have in future.

 

Thank you to all for taking the time to answer my question. Have a great day everyone.

Share this post


Link to post
Share on other sites
 
WheelhorseBob

I changed the oil in both of my hydro’s last year. I think it was original in both. 1978 C161 and 93 520H. In both it was clean with no evidence of water intrusion. I put Pennzoil Platinum 10-30 full synthetic. I won’t be changing it again for a long time unless a seal or something fails.

  • Like 1

Share this post


Link to post
Share on other sites
 
graywolf1939

The hydrostatic transmission cooling fan is OFF !! The thread was STANDARD, CCW to remove the bolt. The bolt is long and it appear s to me that lock-tite, or some other thread locking paste was used to prevent the screw from backing out with CCW rotation of the drive belt

 

  • Like 2

Share this post


Link to post
Share on other sites
 
graywolf1939

I found out WHY the 518 had all the issues when it failed. There is an "E" washer that sits in a tiny groove on the end of the rod that controls the disengage feature for the hydrostatic transmission. That is the handle on the right side of the control panel as you sit on the tractor. The rod runs from the left side body frame to the right side where they is a linkage connected to the lift rod on the control panel floor. When the "E" ring broke, it took some time, but somehow the rod on the left end slipped out of the hole in the body frame, and this allowed the right side to float free and ride out enough to interfere with the drive belt and the cooling fan blades which were all torn off.

 

    So gentlemen, as you can see, ONE tiny "E" washer can cause a lot of damage when it gets old and tired like me, and breaks.

 

Wheel Horse engineering in their younger days did an EXCELLENT job with their designs, however, I noticed the difference between my 1980 C1000 Special and my 1988 518H. The body and frame were still as solid as the rock of Gibraltar, but "little things" is were they decided to try to save some money, such as the darn "E" washer. They knew they could save some money over a more solid design, and they knew the "E" washer "might" last 5 or 10 years, so who gave a damn, the bean counters saved a few bucks. It is a shame because Wheel Horse made the best lawn tractors on the market for years, and has the most loyal customers base that I have ever seen. QUALITY MATTERS !! There are THOUSANDS of customers who would much rather pay extra money and get a quality machine that will LAST. However, there are MILLIONS of new riding mower potential customers that will go cheap because; either that is all they want or can afford, or, they just don't recognize the difference in quality, and what that ultimately is going to cost them in the long run for multiple repairs.

 

I am going to sell my 518H with a Commercial grade 48" mower bed, I want a new mower with features that the 518H does not have, and at age 82, it getting harder for me to take care of this Horse. I will keep the 1980 C1100 as it has a 36" mower bed and the wife can handle that far more easily. So, if anyone is interested in a 518H, please email me or let me know on this forum.

Share this post


Link to post
Share on other sites
 
Handy Don
On 8/18/2021 at 1:42 PM, graywolf1939 said:

The hydrostatic transmission cooling fan is OFF !! The thread was STANDARD, CCW to remove the bolt. The bolt is long and it appear s to me that lock-tite, or some other thread locking paste was used to prevent the screw from backing out with CCW rotation of the drive belt

 

To be clear on this topic. It is NOT the direction of rotation of the belt that would loosen the fan--it is the direction of the rotation between the pulley and the fan that matters..  The resistance to the rotation is the blades of the fan pushing air. The fan tries to turn slower than the pulley and if it did slip, its motion relative to the pulley is CW which would tighten the RH screw into the pulley. The normal screw is a Nyloc, i.e. it has nylon insert that resists both tightening and loosening, as an assist to keeping it tight.

Edited by Handy Don
  • Like 1

Share this post


Link to post
Share on other sites
 
Handy Don
20 hours ago, graywolf1939 said:

    So gentlemen, as you can see, ONE tiny "E" washer can cause a lot of damage when it gets old and tired like me, and breaks.

 

Sir, I disagree with your premise that economizing caused this failure.

I think it is unreasonable to expect anyone to make and sell a tractor that will last for in excess of 30 working years without complete regular maintenance. The owner manuals of the era specifically enjoined owners to get their machines serviced regularly at a dealer. Many owners chose to ignore that advice--some because they did the maintenance themselves and others with a false sense of economy (it ain't broke so don't fix it.)

The service manual for the 518-H is very clear that ALL mechanical joints and linkages be examined and lubricated as needed on no less than an annual basis. For someone uncertain or unable to fully perform these steps, seeking professional help makes sense. 

I doubt any new ZT, even a $10,000 professional commercial model will state in its owner manual "check and lubricate all linkages and moving parts every 30 years".

Edited by Handy Don

Share this post


Link to post
Share on other sites
 
graywolf1939

I agree Dan. But my 518 was regularly maintained by me. I worked in equipment maintenance for over 30 years and know full well the value of regular maintenance. I also have seen the results of "false savings" by going cheap on parts to save a few bucks to stay competitive in a tough market. That rod that I refer to should have had either a clevis pin, or other means to keep it in place because it takes considerable punishment. I lubricated that point every spring and fall before sending it to bed for winter. If the failure were limited to just the "E" washer, no big deal, but when that rod can drop out it's hole in the chassis and cause all sorts of trouble, then a "what-if" analysis would have shown that an "E" ring was not a good design.

Share this post


Link to post
Share on other sites
 
graywolf1939

BTW Dan, thank you for taking the time to point out the info on the fan and rotation. Hopefully, this will be of help to other owners. Real good info !

  • Like 1

Share this post


Link to post
Share on other sites
 
Handy Don
28 minutes ago, graywolf1939 said:

I agree Dan. But my 518 was regularly maintained by me. I worked in equipment maintenance for over 30 years and know full well the value of regular maintenance. I also have seen the results of "false savings" by going cheap on parts to save a few bucks to stay competitive in a tough market. That rod that I refer to should have had either a clevis pin, or other means to keep it in place because it takes considerable punishment. I lubricated that point every spring and fall before sending it to bed for winter. If the failure were limited to just the "E" washer, no big deal, but when that rod can drop out it's hole in the chassis and cause all sorts of trouble, then a "what-if" analysis would have shown that an "E" ring was not a good design.

Thank you for your replies

I accept all but one of your points--that a clevis or other retainer was dictated due to a 'what-if" analysis.

 

The cross-chassis shaft supporting the drive pulley idler does indeed take a lot of punishment, especially since the force on it is asymmetric due to the tension spring on the drive pulley side. Yet I find it very hard to believe that neither the e-clip nor the shaft showed visible signs of wear within one year of failing unless there was some other aggravating factor. Lubrication is not inspection (and I freely acknowledge that removing the side panels on the 500-series units to permit visually examining all the cross-chassis linkages is not a quick or easy task).

 

That said, IMHO a properly-sized, well seated, and lubricated E-clip is an amazingly strong way to retain a shaft. It distributes the longitudinal load (which is very small for this shaft) evenly over three flat sections of the circumferential groove in the shaft and the clip itself--a cotter or clevis would apply all the force to only two points and then to the side of a cylindrical fastener. It offers a truly perpendicular flat surface for handling rotational friction.  It also permits a much closer tolerance for endplay on the shaft compared to cotter+washer installs.

 

As for "what if" failure analyses, most engineers, again IMHO, will focus on areas that can result in injury or death to an operator or other nearby person or that can cause catastrophic damage to the equipment. A busted cooling fan, even adding a possibly ruined drive belt, doesn't rise to this level. The failure is surely aggravating, and a PITA to fix but those are different standards.  

 

Edited by Handy Don

Share this post


Link to post
Share on other sites
 
graywolf1939

All good points Dan, you certainly know your mechanics, if I didn't know better, I would think your were a Wheel Horse Engineer in your day ! 

Share this post


Link to post
Share on other sites
 
Goofey

i think i saw somewhere that the interval was 100 hrs?

 

Also saw Skipper had great result with 0w-40.

Edited by Goofey

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

×
×
  • Create New...