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ZF Transmission Problems

Tony Wells

Tony Wells

Senior Member
Joined
Jul 18, 2019
Messages
635
Location
Tyler, TX
Occupation
HogZilla Keeper
Doesn’t look like a good day to work outside. Been raining a while and radar models show likely rain until noon or so.
I’m supposed to meet a Volvo tech on the 250 digger this morning, but have not heard from him yet. Wouldn’t blame him for asking to delay his visit a bit. At that location there isn’t a building we could limp into. If the machine is where I saw it last, I won’t be able to drive up near it. The loaders keep that mud stirred up into foot deep mush.
We’ll see...

Bigbert, I was thinking about who built the control box. There isn’t any doubt on the t/m. Probably ZF.
 
Tony Wells

Tony Wells

Senior Member
Joined
Jul 18, 2019
Messages
635
Location
Tyler, TX
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HogZilla Keeper
OK, I was wrong. I removed the plastic skirt on the loader, hoping to be able to easily see and access the control box. As dirty as it is, what I thought was the control box wasn't. Bigbert was right...the control box is on the left side of the transmission proper. And tucked up high behind a frame rail. The shift levers, after they go through the floorboard, are simply attached to lever arms that push/pull cables that wind their way back to the control box. This can't be to complex, it's only two cables. There are a couple of electrical components, but I suspect they are pressure and temperature sensors. It's still filthy, and I have made arrangements to have it pressure washed so I couldn't really get any usable pictures. I did see something odd (to me at least) It's in the pic I will post. After moving some things around in my shop I'll get it inside where I can get some better lighting and hopefully pictures that will help. Meanwhile I'll be rounding up the pressure test materials.IMG_2951a.jpg

Obviously we can see one of the spools and linkage, but up higher there is what appears to be a fitting (some sort of hose barb maybe?). The reason that popped into mind is that there is a disconnected hose just dangling but it's a little more towards the front of the machine. However, it would easily reach this fitting and appears to be about the right size. It's open and caked with dirt and looks like it has been like that for a long time. It maybe a bleeder fitting, on the other hand. I've not searched the manual yet to see if I can spot it. Open to suggestions.

So the plan is: Washdown, pressure check, pictures if I can do better, and depending on pressure test report, some plan probably to remove it from the transmission. I'll have it inside out of the weather if it comes to that.
 
Tony Wells

Tony Wells

Senior Member
Joined
Jul 18, 2019
Messages
635
Location
Tyler, TX
Occupation
HogZilla Keeper
mg2361 said:
Neutral start switch and Reverse warning alarm switch.

Bleeder for bleeding the clutch cutout circuit.
Click to expand...

mg, there is one more hiding somewhere then, because there is a low pressure warning light on the dash. I can't see everything yet. I was tired when I was looking yesterday, so I probably just missed it. Someone has been under there already. WIRENUTS in use :mad:

Bigbert, I'll go by the Parker store today and see if they have the proper connections. Port 65 is an M10 x 1,5 (M10-1.5 over here:)) Those all ORB style? Seems the specifics were in the manual. I'll check. That map is clearer than the scan in the manual also, so thank you! My eyes (glasses) need renewing.

Must have been tired when I made that post too....that control is on the RIGHT side of the machine.
 
Bigbert

Bigbert

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Jan 2, 2016
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327
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Germany
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Consulting Engineer
Tony,
I'm not sure whether you will be able to get the M10x1.5 fitting, as these are not very common. Guess, the thread on control block is a M10x1, please check. Wondering how a M10x1.5 would look like.:confused:
However port 65 is the main clutch pressure which is distributed to clutches with the spools. So for investigation of the system the clutch pressures are relevant, not 65. All ports max. 250 PSI.
 
Tony Wells

Tony Wells

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Joined
Jul 18, 2019
Messages
635
Location
Tyler, TX
Occupation
HogZilla Keeper
Frankly, I can't see that they would use a M10 anything on a hydraulic fitting. The ID would be very small, unless that is the ID. I have spent the last hour or so looking for something in the documents that I have been provided and cannot find it. There was a list of needed test fittings, even specifying a 300 PSI gauge. There was mention of a quick-disconnect and the use of some ORB connections as well. But I cannot find it. My filing system leaves something to be desired, evidently. My solution is to go pull a line from the diagram and see what it is, I suppose.
 
Last edited:
Tony Wells

Tony Wells

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Joined
Jul 18, 2019
Messages
635
Location
Tyler, TX
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HogZilla Keeper
Nige, you are a man after my own heart. Chopping off hands has always been a favorite of mine. Hatchet works too.

OK mg, which paper had those listed? I know I have it, I just can't find it, even still attached to the PM's! I gotta slow down and take a little time on this. I feel like I am rushing.

Things went sour today. A machine caught fire, so as I was trying to wash the 544 down, I had to go dig around in the oily burnt sawdust to find what happened and fix it. It appears as though the machine has been leaking oil for months and attracting sawdust, but the op swears it was washed down less than 2 weeks ago. I don't believe that. The entire machine looks like it hasn't been washed down in 6 months. Even inside some of the control panels, there is a mix of hydraulic valves and wiring, and 4 inches of buildup of fine dust and oil. It has doors, but they aren't really sealed. But it hasn't been cleaned out. I told the owner it will no doubt burn again and maybe worse unless he starts pushing those guys to clean the equipment. It just has to be done. I don't see how they do any PM like grease or even filter changes. They probably don't. Needless to say, I did not even try to get the pressure test gear for the 544 today. Got it halfway washed, and will try to get the helper I have to soak it down with degreaser and have another go at it tomorrow. At least I can see the connection side of the control box now. Still going to be tough getting to. But have to do it.

Since suspicions are that two incorrect clutches are pressured up, wouldn't it make sense to have a couple of gauge sets on it? Or just move from one port to the other and log all the results for each gear selection?
 
John C.

John C.

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Jun 11, 2007
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12,870
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Northwest
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I use adjustable end wrenches all the time. Most of my tools are so old and worn that the adjustable one has a tighter fit. I had an old timer tell me that it was time to retire when the 11/16" end wrench rounds off a 3/4" bolt head. My 11/16" does that now, but the fit all still works for most of what I do.
 
Tony Wells

Tony Wells

Senior Member
Joined
Jul 18, 2019
Messages
635
Location
Tyler, TX
Occupation
HogZilla Keeper
I use them now and then...when I need a cheater pipe on something. I also have a tiny one to use where I can't see ahead of time to guess the size. If they aren't worn out, they have a place. They also bend sheet metal:)
 
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