D6H transmission overheating

[Pralhad Birdi]

The oil is sucked from the inside to the outside of the screen as shown by the arrows.
Therefore anything interesting, metallic or otherwise, will be found either on the inside of the screen or stuck to the magnets.

View attachment 298713

 

[Pralhad Birdi]

The oil is sucked from the inside to the outside of the screen as shown by the arrows.
Therefore anything interesting, metallic or otherwise, will be found either on the inside of the screen or stuck to the magnets.

View attachment 298713

 

[Pralhad Birdi]

Poke a piece of wire or similar down each hole in turn. Can you determine if one or other of them has no outlet.?

You'll have to open the control valve up to clean it internally at some point. That point may just as well be now. It will also enable you to compare the parts and their orientation/assembly inside the valve with the parts illustration you already have. Attached is the D&A procedure for the control valve.

Thank you for the document.
I’ve got the control valve apart, and both the holes are right next to each other, through and into the same cavity at the bottom. There’s nothing blocking oil flow through either one, so even once the orifice is installed, the other one will be open through right next to it.

 

[Pralhad Birdi]

 

[Pralhad Birdi]

 

[Pralhad Birdi]

So both holes have what appear to be machined seats. So the top one is where according to the diagram the orifice is meant to go. The bottom one is the one that I can’t figure out.

 

[Pralhad Birdi]

 

[Pralhad Birdi]

And that’s the bottom of the body, showing where the holes come through right next to each other.

 

[Nige]

First things first. The screen & magnets don't look too bad at all, especially if they were not cleaned after the supposed recent "transmission failure". I've seen them totally solid with burned clutch material. Clean them well, blow off with compressed air, and they can be reinstalled.

BTW is the oil from the photo of the magnets what came out of the transmission.? That is absolutely horrible and should be junked if it has not been already.

 

[Nige]

Now on to the orifice. Looking at your photos I am of the opinion (and I stress it is only an opinion) that one of those holes, I think the lower one, should have been plugged or had a ball bearing or similar pressed into it in a similar way to the one on the top right. It's a common thing with valve bodies, there are passages that have to be closed to make everything else work as it was designed to do. I just hope someone else can comment on that.

As I said previously I think when you receive the orifice it will be obvious which of the two holes it fits into.

 

[Nige]

So both holes have what appear to be machined seats.

And if you look closely you can see what appears in the photo to be the remains of a cap/plug/whatever that is totally separate to the valve body. I have indicated it with an arrow. I think this somewhat confirms my theory that the lower passage should have a plug in it.



And if the photo is enlarged, even though the resolution is poor, you can clearly see the broken edge of what was a blanking cap that was at one time pressed into that passage to close it off.

 

[Pralhad Birdi]

First things first. The screen & magnets don't look too bad at all, especially if they were not cleaned after the supposed recent "transmission failure". I've seen them totally solid with burned clutch material. Clean them well, blow off with compressed air, and they can be reinstalled.

BTW is the oil from the photo of the magnets what came out of the transmission.? That is absolutely horrible and should be junked if it has not been already.

All cleaned and being reinstalled.
Yes that’s what came out of the bottom when we took the strainer off, so definitely going to sack that off.

 

[Pralhad Birdi]

I

And if you look closely you can see what appears in the photo to be the remains of a cap/plug/whatever that is totally separate to the valve body. I have indicated it with an arrow. I think this somewhat confirms my theory that the lower passage should have a plug in it.

View attachment 298772

And if the photo is enlarged, even though the resolution is poor, you can clearly see the broken edge of what was a blanking cap that was at one time pressed into that passage to close it off.

View attachment 298773

That makes a lot more sense now!! Thank you!
So let me find something to blank this off with again, and then install the orifices as soon as I get them, and put the whole thing back together.

 

[Nige]

You should really remove the remains of the broken cap from the hole first, then measure the hole diameter and use a piece of suitably-sized round bar to make a new plug. When you install the new plug it should need to be lightly driven into place with a hammer.

 

[Pralhad Birdi]

And if you look closely you can see what appears in the photo to be the remains of a cap/plug/whatever that is totally separate to the valve body. I have indicated it with an arrow. I think this somewhat confirms my theory that the lower passage should have a plug in it.

View attachment 298772

And if the photo is enlarged, even though the resolution is poor, you can clearly see the broken edge of what was a blanking cap that was at one time pressed into that passage to close it off.

View attachment 298773

Also, awfully sorry to be a bother, but do you think there might be a part number for the blanking plug?

 

[Pralhad Birdi]

You should really remove the remains of the broken cap from the hole first, then measure the hole diameter and use a piece of suitably-sized round bar to make a new plug. When you install the new plug it should need to be lightly driven into place with a hammer.

Sorry just seen this. I’ll machine one out of round bar.

 

[Nige]

Also, awfully sorry to be a bother, but do you think there might be a part number for the blanking plug?

There might be a Part Number but it is not visible in the system. Your best bet is to make something to fit.

 

[Nige]

Another thought. After you install the plug use a centre punch to make a couple of dots at the interface between the plug and the valve body to ensure that it can’t move.

 

[Dave Neubert]

from what I can remember there should only be the one hole for the orifice I don't remember having to figure where the orifice went. I know that with out it you will have major high pressure. I had a customer that his filter housing blew apart from the pressure

 

[Nige]

While you have the control valve body apart I suggest to check closely for a small circular disc of metal with rough edges that will correspond to the missing piece of the plug. It must be somewhere and you don’t want it to get stuck somewhere that could cause chaos to the clutch oil flows. I would hazard a guess that it’s very likely still somewhere in either the valve body or the manifold that fits directly under it when it’s installed on top of the transmission.