Hydraulic cavitation/low transaxle fluid question

I bought a used JD 155 and have put 1 hour of mowing time on it twice, so about 2 hrs total. I noticed that after 20 to 30 minutes of mowing that the hydrostatic drive would become slightly more noisy. Last night I found the cooling fan blades worn down to the hub. No problem I picked one up for less than $5 at the local JD store. While I have the wheels off I decided to pull the fill plug and see where the level is and color of the fluid. I can't find any!! I used a siphon hose to see if I could suck some up. Yes, I got a dribble in the hose, but that was it. Clean with a few sparkles of metal in the teaspoon that I was able to get. And yes, I know that free floating metal is bad in hydraulics.

The total capacity of the drive is 2 1/4 qts and I put in a whole quart before it was full!

My question is how badly have I damaged this drive? Am I looking at a rebuild in less than a year from now, or could it possibly be okay with just a slightly more pronounced sound from the pump. It sounded like a power steering pump squeal prior to messing with it. I thought it was fairly common sounding and only started looking around when it got hot and would hesitate to back up.

It seems to have good response now and only groans when I push the fwd pedal down fast. If I take off at what would be considered a "normal" speed it only whines slightly - again, normal sounding, but quieter than before. Backing up is only slightly more noisy. The pedals are at least twice as firm as they were before and I have bleed the system by having the rear jacked up and going back and forth between fwd and reverse.

If it makes a difference the hydrostat drive is a K51b made by Tuff Torq. I will probably give Tuff Torq a call tomorrow as well. I know the repair parts can easily exceed the $300 mark, but I paid $800 for the tractor and 42" Freedom deck.

Sorry for being so long winded, but it's hard to describe sound with only a few works.

Thanks in advance.

I don't think anyone can tell you how much damage you did but we know you didn't do it any favor running it low on fluid.

This points out how important it is to check things when you buy a used mower before using it.

Yes, you are right Bart, and I'm old enough to know better too. The salesman said that it had been through the shop and I didn't ask to see the work order. I just took his word.

Always, always, always check your fluids.

I just got off the phone with Tuff Torq. They too say that I didn't do the transaxle any favors. This I knew. They suggested that if it's not slipping more than likely it will be okay.

The good news is that if I do need to rebuild, the low fluid cavitation (if present) is confined to the pump, motor, and center housing. So, the casing should be undamaged. It will still be a minimum of $300 for these parts which I can handle due to my own foolishness.

I also asked about upgrading internals to the K57 and they said it would depend on my serial number as to whether they would fit or not. It sure would be nice to have that locking diff...

In any event, after mowing season I will pull the transaxle and dump the fluid, split the case, and clean the magnets. I can inspect then for signs of wear and decide whether to rebuild or not. My thoughts at the moment are to save the $$$ for when it is really needed. But someone has already been inside this thing once so I have to wonder if they really did anything other than short me a qt of oil.

Thanks Black Bart for your insight.

honestly?.....dont waste your time...just buy a good used one...you dont want to know how much it costs to rebuild that:thumbdown:..i would change the fluid again and again until those metal particles are gone

TerryD said:

Yes, you are right Bart, and I'm old enough to know better too. The salesman said that it had been through the shop and I didn't ask to see the work order. I just took his word.

Always, always, always check your fluids.

Click to expand...

Sounds like a mower salesman and a used car salesman are related.

Heck, I'd change the fluid out periodically (one of very few times I wouldn't reccommend synthetic lube) and run it until it breaks. Have another used unit, in known good condition, and put it in when the time comes.:thumbsup:

Update: I've returned the mower to the dealer with a list of issues and told them to either make it right or keep it.

Thanks everyone for your responses. We will see how it goes.