The transmission on mine has always made noise from day one, but it never slips. With nothing to compare it with, I always took this noise as normal seeing I bough it new. Also I don't know how much noise yours is making?
Thanks for answering my post. My unit whines, not a sound I would equate with internal mechanical parts fighting with each other. It also does not want to go up-hill - meaning a gradual slope nothing too steep. I have run 20-50 multi grade motor oil in it by the recommendation of a mower mechanic who knew about the Ferris hydro. M ine is about a 1995-6 model year as best as I can tell.
Rob
Thank you again for coming back to the conversation. No Where have I seen a blow-up showing the internals of the hydro unit nor a shop manual on this hydro-drive. I would surely like to have one as this is a somewhat blind adventure on my part. [fools rush in where angels fear to tread] I have posted more photos if you are interested. I paid $350 for this machine knowing it would need an engine before long. It did, and rather than take it apart and tie up the machine for a long time, I chose to buy a good used motor and transferred the carb, governor mechanism, and exhaust muffler. I believe there is a spark retard circuit that is not hooked up right because the newer engine had a different wiring harness than the older Kohler 22HP. Good to hear the newer machines have a different hydro unit.
I am sure Ferris didn't make the hydro system. Maybe find out who made it and get information from them? The Kohler came with what they called Smart-Spark ignition system is what I think you are calling spark retard circuit. This Smart-Spark system was built internally in the engine itself and would nothing to do with the external wiring to the chassis. The only wiring that may be different would be to the charging and starter systems. The only wire to the ignition system is the wire to ground out the coils in which go's to the ignition switch.. The Kohler electrical systems I have worked on in my shop and in more then in just the brand of Ferris mowers.
Looking at your photos you will see wear grooves between the intake & discharge ports.
This plate has to seal against the rotor, however there is no seal there.
Thus it requires that the plate and the rotor are mirror finish smooth & flat.
If that is not the case the pump can not pump.
Yours looks rather like an Eaton 751.
Ferris do not make pumps , gearboxes or transaxles they are all bought in.
Eaton have all their manuals as an free download on line otherwise I can send you the 751 I got a while back to do a job.[/QUOTE
This gives you a good start. :thumbsup:
Don't use Lucas.
You can go to heavier oil 30w 50/ 30W 60 etc.
Using a heavier base oil is a lot better than trying to thicken up a light base oil.
If it looks like the friction plates are excessively worn, most clutch & brake relining factories should be able to replace the friction material.
If those wear groves are bleeding off pressure you can get them refaced but it won't be cheap.
After taking the unit apart and looking for obvious worn parts in addition to not getting any material leads on the GeRotor pump nor the two clutch discs, I am going to put it back together and live with the noise and hill climbing weakness. Inside the axle hubs, where the the reactor plate is located, I don't see enough wear on that plate to condemn its functionality. There is a little bit of scoring in the casting under the GeRotor pump assembly but that cannot be remedied without a new hydro-static transmission. Eaton closed the parts supply chain for the 751 series in 2011.
I am replacing one of the outboard bearings and seal on the right side (short) axle shaft. With that, and new 20-50wt. oil, I will conclude this endeavor of fixing the Hydro unit.
Thanks for the advice. Rob
I just discovered something that I believe is significant in this trans-axle. The ball pump rotor does not have springs behind the 5 balls.
Photos included >>
No idea about the springs in the pump unit but as it is spinning quite fast centrifugal force should force the balls out and I expect the cam pushes the balls in creating the pumping effect.
If you have not lapped the plates then I doubt the tranny will work.
The volume of oil pumped is very very small so given the chance of passing between the two oil galleries via the scoring or driving the wheel motors, the oil will follow the path of least resistance.
Now it could be nothing more than at those speeds all the oil passes through the scoring and when spinning faster, enough oil passes through the engines to get them to work.
In your last photo you can see the slots for the oil flow and the wear between the slots,
The oil that the G rotor pump is pumping is passing along the grooves rather than going to the motor.
Like anything under pressure the oil will take the path of least resistance so on level ground 90% might go through the motor and 10% goes through the wear grooves.
Going up hill the motors are a higher load than the wear grooves so 90% of the oil now escapes along the grooves between the intake & discharge ports or strait out under the sides leaving you with 10% to power the motors.
The groaning you can hear is the sound the oil makes as it escapes from places where it was not supposed to.