BX2200 Transaxle leak

[weldguy]

My 2001 BX2200 has developed a leaky transaxle. I just CANNOT find the source of the leak and I'm about out of patience. The cooling fan tends to spread it around which isn't helping.

I've replaced the input shaft seal, front drive output seal and front PTO drive seal. All bolts are tight. While it was on jack stands, I removed the fan, added dye and ran it under load for five minutes at 3,000 RPM laying under it with a black light. I eventually saw a drip forming on the bottom, but could not see where it originated. Nothing seen on either side or at any line fittings.

After shutting it down and eating lunch, there was my two to three inch diameter spot on the floor. Again looked with the black light and only found fluid on the bottom.

How likely is it that I have a bad gasket, possibly between the finned casting and main body of the transaxle? I have 1200 hours on it and it has never leaked a drop anywhere until now.
Anyone else run into this frustrating problem?

 

[ehenry]

I know its a different tractor but I have a B7300 that had a hydraulic oil leak that I hugged hell trying to track down. It turned out to be the housing where the mid-pto housing mated to the transmission. There is no gasket there. Only a sealing compound.

I cleaned the area really well where the two housings were bolted together with brake cleaner, put a clean piece of cardboard under the tractor and it wasn't a couple hours later there was a drip on the cardboard. I ran a finger around the pto housing where it mates the transmission and it was wet with oil but the transmission housing was dry. I drained hydraulic oil, pulled and resealed the pto housing and haven't had a leak since.

 

[weldguy]

I'm crossing fingers and anything else I can cross...
I was able to ask the Service Manager at the local Kubota dealer if he had any educated guesses where my leak was coming from. Without even taking a breath, he asked if I keep it in an outbuilding, which I do. He then confidently said mice have chewed on the trans return line mounted between the transmission and fuel tank - totally invisible and inaccessible.

I'll need to remove the ROPS, floor, fenders and fuel tank to get to it. He said he has seen it a lot. I hope he is right... it's a ton of work.

 

[tinkerwitheverything]

Before you get to carried away I had a Massey GC 2300 that did the same thing.The rear PTO seal was the culprit. It would seep just enough that you couldn't see it. The oil would always show up at the botoom of the trans. I to thought it was the cases leaking. The oil traveled down along the seem of the two halves and would show up on the bottom. Drove me nuts trying to find the leak.

 

[D2Cat]

Check with your John Deere dealer, and see if they have some dye you put in your hyd. oil to make it easier to read on the dip stick. They have some that can be seen with a black light. That would make finding the leak easier. Clean the area with a power washer and see what you find.

 

[weldguy]

Yes, I added dye, but couldn't see the source.

 

[whitetiger]

Did you check at your axle shaft seals? It is very common for them to leak and the oil runs down to the center and drips on the ground.

 

[weldguy]

Yes, I looked everywhere, including the axles. My drip ends up on the bottom of the pump housing near the front. Thats why I originally replaced the input shaff seal, the mid PTO output seal and front drive output seal.

As for the return line that the Service Manager suggested, , lots of work for another dead end. No signs of a leak there.

Yet another surprise from Kubota... While I had the fuel tank out I wanted to replace the fuel sending unit gasket. I remember reading there was a later part number that sealed better.
SURPRISE... can't buy the gasket ONLY. It comes with the later sending unit for $124. I will just continue to stop just short of filling the tank, thank you.

 

[weldguy]

VICTORY - AT LAST

The hydraulic leak was getting pretty serious... had to add 10 to 12 ounces every time I mowed my 2.5 acres. The only thing left to check out was the HST pump. I began my tear down at 9:15 am and finally could get to the pump bolts at 5 pm. The next morning I removed the pump from the transaxle and began cleaning the outside. As I was using a rag and screwdriver to clean out the allen head bolts, I noticed five of the eight bolts holding the pump halves together were FINGER TIGHT or looser!!! Not a speck of Loctite on any of them.


After several trips to the dealer for a gasket and O-rings (he finally got them all right) I reassembled the pump and mounted it on the transaxle. Then it was figuring out where all the linkage pieces went putting everything else together. LOL.

NO LEAKS!!!

I asked the Service Manager for a ballpark figure on that repair. He thought a bit and said, "About $1300 labor."

 

[ipz2222]

Too late for you but maybe can help others later. Clean everything off good the dust with baby powder, or any talcum powder. Most containers are plastic and have the lid with holes in it. Just a couple of quick squeezes will push the powder out and against whatever is leaking. Then run it and look. The powder will quickly change color when it gets wet.

 

[lugbolt]

severe loading on the HST can cause the bolts to stretch, then the halves will develop a leak. "Severe loading"--meaning, among many things, deadheading the HST, such as trying to bulldoze trees, pull stumps, that kinda thing, also--have seen where excessive and FAST directional changes can cause it too. Such as, trying to ride a wheelie-but that's most common on zero turn mowers. Yes I've seen it. I saw one actually blow the halves apart and break some of the bolts off.

The amount of force on the HST halves under a big load is pretty mind-boggling. There's 10 pistons I think in these, 5 on the fixed displacement pump and 5 on the variable displacement motor, each piston is roughly 5/8" diameter, and whatever the high relief is. Say the high relief is 3500 psi. That'd be somewhere in the 22,000 lb of force range, OTOH.