First post here, glad I got invited by the sister site. Anyway, wife bought a new car so I'm stuck with old lawn tractors, our old JD LT180 lunched the TuffTorq hydro, so I went to refurbing this 2048 that had been sitting in the back for 5 years. Had to completely go through it changed most all the idlers and all the belts, drilled a hole in the Hydro-Gear and installed a plug so I could do a complete oil change with the correct synthetic. Started mowing for a few months limping along with it until I adjusted the valves in the intek 21HP before finally getting up to full power. Now I'm at the point where toward the end of mowing my 1 acre where it starts to struggle going up slight inclines. I have learned to do the one area with a larger incline first while it's still relatively cool, then the smaller incline next. But still would like to get more out of the transaxle.
New drive belt installed correctly seems pretty tight, cooling fan is missing 2 blades out of I think 8, debris is clear off the top of the hydro. I do notice the Transmission Disconnect Rod is kinda funky, it does work but doesn't really stay in the slot at all when I disconnect the trans. Where should I look next?
Mulligans have Hydros for very good prices if you want to stump up for one for either mower.
Hydros have to be bleed very carefully to get rid of all of the air.
If it looses power when hot then you either still have air in the system or need to go to a heavier grade oil.
Must use fully synthetic as std oils burn and the debris blocks up the oil passages.
Drilling the cases is a stupid thing to do unless you do it to an empty case from the inside out.
There are magnetic filters inside to catch tiny steel wear fragments but only a coarse mesh to pull out non magnetics like alloy.
Because the swash plate runs directly on the valve chest , you should always purge them on slow idle.
Yeah now that I think about it it's rather stupid to do it that way. I used 15W50 Mobil 1 in it. I might try and finish the season with it and drop it over the winter do it up right clean the filter etc. Thanks for the info.
One of my pensioner customers is running 20W 50 in his hydro which is shot because he "could not afford to get it looked at ".
He now has to mow his 3 acres over 3 days.
It is quite hilly so he starts off with the hills the as he looses drive he goes on to the flatter bits.
"Typically, an engine oil with a minimum rating of 9 cSt (55 SUS) at 230°F (110°C) and an API classification of SL/CD is recommended. A 20W-50 engine oil has been selected for use by the factory."
I live in Louisiana, operating temps are 90-95F for 4 months of the 8 month cutting season, and is never run at temps below 60F. What would you recommend?
Yeah been looking around see who carries what, last time all I could find quickly was 15w-50. I see the auto parts stores carry motorcycle oil in the 20W-50 range, might get that.
Yeah been looking around see who carries what, last time all I could find quickly was 15w-50. I see the auto parts stores carry motorcycle oil in the 20W-50 range, might get that.
Ended up using some motorcyle 20/50 synth, drained the new oil out had shavings
floating in the oil. I have done the purge procedure 10 times , but it still starts slow and peters out after getting hot.Considering ordering a seal kit and pumgoing over the hydro hoping to get more life out of. Couple hundred in parts is worth it, but not the $7-800 range. What am I getting into?
In theory the hydo boxes are simplicity itself. a beautiful piece of engineering with few moving parts.
However if you look at the parts breakdown you will see the rotating valve chest runs against a stationary manifold plate with nothing between them to make a seal apart from some precision machining.
Similarly the pistons in the valve chest also have nothing to seal then except a close finish.
Thus any abrasive in the oil plays havock with the fine precision finish.
They are assembled in clean room conditions under positative air pressure to exclude dust.
Thus when you rebuild them you have to be anal about dust exclusion.
I do them in the bathroom after washing down the ceiling walls & floor.
Before I take the tranny inside it gets a degrease then a soad blast then a hot water wash to make shore there is no dirt on them before I pull them down.
Everything gets a bath in degreaser then the ultra-sound then goes in plastic sealing bags till they are needed for reassembly.
long rubber gloves and full painters paper coveralls complete with hood.
One set when I pull it down and a second new one when I reassemble.
I also set the video camera up on a tripod so I can review how it came apart before I put it together.
Big bits get covered with a damp fibre free shop towel.
To date only 1 I have rebuilt as failed.
Now I might be a touch anal but down here I have to warrant the job for 6 months.
Thus if I introduce grit with causes a tranny problem I am up for a new tranny.
Lots of videos which show blokes working on them on a grubby shop floor and then driving away with a perfectly working tranny.
They don't follow up in a year when the unit is totally stuffed.
Everything goes back in wet with oil and I purge the tranny with a piece of hose connecting the input shaft to a step drill in my 1/2" power drill.
If you are going to do it in your shed, wait till you are in for a week of solid rain before you reassemble it to clean the dust out of the air or if you are fog prone just after a heavy fog.
Thanks for your procedure, duly noted about the cleanliness aspect. So I'm guessing I have to tear it down see whats worn then order parts? Or is there a list of what's commonly changed out in a rebuild?
You get a pump/motor kit that is complete apart from the axel seals & oil.
It is about 1/2 to 2/3 the discount price of a new tranny depending upon where you get them from.
While they are simple in construction they are high precision machining and high precision cost a lot of money.
I have access to polishing wheels from a previous life as a metallurgist so I can polish the surfaces down to 2000 grit with wet & dry then pop them on the plate and take them down to 4 micron.
Sometimes this works, and sometimes it dosent , it all depends where the wear is.
If it is just the valve chest & manifold plate then they can be lapped if the wear grooves are not too deep but if the wear is in the cylinders then it is scrap metal.
I looked over the Hydro-Gear service manual and got a few part #'s, seal kit, 70331 10cc Cylinder Block Kit $67 (2) Hydro Gear 70477 KIT, CENTER SECTION and 50551 Thrush Ball Bearing (2) shipped for $275. Might try and pull it tomorrow, break it open and see if anything else looks bad before ordering. I don't mind dropping a bit for new pumps. But I didn't see the " pump/motor kit that is complete apart from the axle seals & oil." you mention. But didn't search any deeper than the above mentioned parts.
edit- fresh look at service manual today, didn't take hydro apart, but guessing this can be done with 2 sets of cylinder block kit, seal kit and mill down of the Center Section Assembly. Something like US160 unless other parts are damaged.
Finally tore it down just to look at it, see if it's worth putting any money in it. Looks like a new center section at the least. Still pondering what to do with it. They are $145 online, considering milling it down but it looks too far gone.
Holey Hell Batman how did that one get past Quality Control will all that porosity in the castings.
How old are those units ?
If not too old send those photos to Hydro Gear and see if they will come good with either free replacements or new parts at cost.
All those holes you can see were at one time a little bubble in the metal.
he ones that were ruptured by the machining would act as little oil reseviours which would be fine, but the ones that were just below the surface so wore through during service would yield little flakes of alloy which would grind into the working faces and drastically reduce the working life of the pump or motor.
Those really deep scores would have been caused by that happening.
In other words they are defective in materials quality.
So ask nicely and see how you go.
You might like to use a line like
" I think I need to replace these items on my ???????? transmission which failed last year and left me stranded
A friend looked at them and said the castings were defective due to excessive porosity and should never have been allowed to leave the factory
I would appreciate you opinion on replacements"
Good luck.
And don't even consider machining those as the castings are defective and can not be repaired.
When you start with an enquirey and not a demand it is amazing what some companies will do.
If it embarasses them enough to at lest give you wholesale on the new parts you are 40% ahead.
Or they might go overboard with technical help or send you a full rebuild kit at a discount or just laugh.
I have found Hydro Gear to be very helpful to me and quite supportive so it won't hurt.
The castings are definately defective I can tell you that having been a foundry metallurgist in a previous life.
They did not even need to be machined, you can see the defects on the outside of the raw sections.
So Hydro gear will also recognise that at the first glance.
Thanks for your insight this whole thread. I'm going to do just that, start it as an inquiry like you mention. Because I'm in the position of needing the mower and not having much funds right now. It's at least worth a try. Will keep you posted. I might even wait a day or two so it won't be in the pileup off the weekend.
Please find below a link to the service and repair manual for your transaxle. Replacing the center section will be needed. Attached is a schematic with part numbers. You will want to check the lower part of the cylinder blocks for scratches or scoring as well. The second link below is to our service center locator. We do not sell anything directly from our manufacturing facility so it will be necessary to work through a service center.
When you do the work please remember that these unit are mad in a sterile dust free factory so you , your working area and the box itself can not be clean enough.
FWIW I work out of a disused house.
When I split a hydro box, I degrease, pressure wash, soda blast then pressure wash the box again before taking it up to the bathroom.
They get worked on in the bath, after I have wetted down the room with a fine spray hose.
The box gets covered with a damp cloth ( old curtains ) every second that I am not working on it.
After adopting this method all my box repairs have been good.
Just bear this in mind.
A vry small amount of dust you can not see will do a lot of damage inside the box.
You see a lot of videos of people "fixing" them in open grubby workshops & "mums" dirty garage.
What you don't see is that 2 years later the box is trash again cause dust got in.
