TC33 DA Main Seal Hydraulic Leak - Spot Check My Repair Plan Please

random2708 · Jun 13, 2013

So we have been in the middle of a landscape project at the home acreage that has been hard work for my little TC33. Yesterday, the hydraulics became sluggish including the drive. Brought it back to the shed, it was obviously beginning to show lack of fluid. Shut it off in the yard, humped fluid out to the critter, off the bottom of the dipstick. Added fluid and brought it back in where it displayed a fast leak underneath the tractor. I apologize, but I just don't know the correct terms for the landmark parts underneath this machine . . . I have been on a couple of the parts dealer sites trying to identify them without success so far.

The first picture is looking from the left side facing slightly backwards. The forward facing mid PTO shaft is visible as well as the main drain plug for the hydraulic system. The seam between the two block components is the leak site. The bolts holding these two assemblies together are finger loose.

Here you can see where I spun out a bolt using just my fingers. This is looking up, the drain plug is lower left.

But I have another concern. Moving forward on the tractor I wiped oil away to see if there were other issues. Behind the rear mount of the stabilizer bar there is a small threaded hole in the casting. Above the hole on the side of the casting there is an oil line entering the casting with a 90 degree fitting. This hole had some dirt/debris in it, was not leaking oil, but I cleaned it out to see what it was, thus how I became aware that it was threaded. There is some seepage here now as well, but for the life of me I can't even deduce the purpose of this casting or this hole, nor can I see where the casting was ever filled with fluid. At least none that I have been topping off.

So here is my request for help:

The bolts that secure the castings where hydraulic fluid is leaking appear to have a grey coating on the ends. I am going to remove the bolts one at a time, clean the bolts, lock washers and the casting faces. I am going to reinstall them. I am presuming that the grey coating is the Grey Loctite/RTV sealant type compound. Designed to hold the bolts but remain flexible and endure higher temperatures.

Do you agree - should I use grey loctite?

Any help on tightening the bolts? I presume they need torqued . . . Can anyone provide the torque settings?

Finally, can any one tell me the purpose of the forward casting in the last picture and suggest what should be done with the small threaded hole?

Thanks in advance and with warmest regards,

Random

jinman · Jun 14, 2013

You will have to base your torque on bolt size and material. The head of the bolt has both size and hardness for metric fasteners. Use those numbers and look up the wet torque values.

To my knowledge, Grey Loctite is a gasket material, not a thread type locktite. The chance of any locktite doing a good job in that application is also probably slim because you'll never get all the oil off the threads as long as there is seepage from the reservoir. I think I'd tighten to torque specs to see if the seep stops. Then recheck often to make sure the bolt stays tight. You might want to use a new lockwasher to help hold the bolt.

Sometimes oil gets into recesses when it is being blown by the engine cooling fan. That threaded hole needs to be spotlessly cleaned with a good degreaser and maybe some carburetor cleaner to ensure all the oil is out and rechecked to make sure it is seeping before doing anything. It too might be a seep you just have to live with if it is very small. Very few tractors don' have some type of drip or seep. A drip pan on your garage floor under the tractor may be the only solution if it is a very slow seep. If it is coming out fast, then you might have to drain the reservoir dry to even be able to attempt a repair. Of course, if the hole is deep enough, you might put a short bolt in it with a fiber washer under the head, but you have to be very careful and not bottom out the bolt because it could cause your crack to become even worse if one exists.

random2708 · Jun 14, 2013

jinman said:
You will have to base your torque on bolt size and material. The head of the bolt has both size and hardness for metric fasteners. Use those numbers and look up the wet torque values.

To my knowledge, Grey Loctite is a gasket material, not a thread type locktite. The chance of any locktite doing a good job in that application is also probably slim because you'll never get all the oil off the threads as long as there is seepage from the reservoir. I think I'd tighten to torque specs to see if the seep stops. Then recheck often to make sure the bolt stays tight. You might want to use a new lockwasher to help hold the bolt.

Sometimes oil gets into recesses when it is being blown by the engine cooling fan. That threaded hole needs to be spotlessly cleaned with a good degreaser and maybe some carburetor cleaner to ensure all the oil is out and rechecked to make sure it is seeping before doing anything. It too might be a seep you just have to live with if it is very small. Very few tractors don' have some type of drip or seep. A drip pan on your garage floor under the tractor may be the only solution if it is a very slow seep. If it is coming out fast, then you might have to drain the reservoir dry to even be able to attempt a repair. Of course, if the hole is deep enough, you might put a short bolt in it with a fiber washer under the head, but you have to be very careful and not bottom out the bolt because it could cause your crack to become even worse if one exists.

Was bumming with no replies first thing morning, but didn't worry because I knew that Jinman would be along to help me out! Thanks brother!

To keep oil from running any more on mother's garage floor I tightened up the main transmission housing bolts last night. I pulled them out, wiped them down, a couple I cleaned in the parts cleaner. They all had some sort of permaseal or the like on the threads, I presume it was squeezeout from when the two castings were initially assembled. Put a little medium blue loctite on the bolts going back it, just because it made me feel better. Just tightening the first one stopped the drip. I got the bottom four all back in. There are at least two more that were relatively loose up high (they come in from the back). Not sure how I am going to get in there on those yet. Not sure how I can torque all the bottom ones either as I required 4 different combinations of sockets/extensions or wrenches to get them where they are now.

No leaks at all from the joint that was the main culprit.

Still not sure what the front casting is for and why there is a threaded hole in the bottom. I just can't tell. I thought at first that the drips were hydraulic oil that had migrated forward somehow and was coming out here after collecting in the casting above, but I can't see that there should be a path would allow this.

I'm just going to watch it for now, but I sure wish I knew what part of the drive train that was . . .

I also read a fair amount about the frame breakage's that have occurred in the NH TC series when the loader was being overused. That is absolutely what I was doing, using the loader hard because the skidloader was at a jobsite. Wondering if that led to the bolts loosening up on the transmission casting?

Regards,

jinman · Jun 14, 2013

I don't know if your hard use loosened the bolts, but loose bolts absolutely lead to broken castings. All bolts need to be tightened to spec so that the entire load is shared by the entire casting. That's the real danger in having loose bolts between major components of the running gear. It sounds like you are on top of the problem and doing all the right stuff in my opinion.