D6H transmission overheating

[Pralhad Birdi]

I would say so. That diagram I posted earlier (Post #75 above) showing Section G-G with the "orifice-plug" in one hole and what appears to be an empty hole right next to it would suggest that is the correct arrangement.

I would be interested to hear what others think.

Have you got the transmission cooler off yet.? What did it look like inside.?

Okay.
Yes I took the cooler off and sent it off to get cleaned. They put a flushing agent through it and whatnot, but nothing major came out, just a bit of sludge.

 

[Pralhad Birdi]

I would say so. That diagram I posted earlier (Post #75 above) showing Section G-G with the "orifice-plug" in one hole and what appears to be an empty hole right next to it would suggest that is the correct arrangement.

I would be interested to hear what others think.

Have you got the transmission cooler off yet.? What did it look like inside.?

So this essentially means that the control valve didn’t really have any issues? So what else do you think I can check?

 

[Pralhad Birdi]

And I genuinely appreciate everyone’s time, patience and help with this.

 

[Nige]

Did the screened orifice show up yet.?
Try blowing through the old one and the new one. Can you detect any difference.?
Install the new orifice, reassemble the control valve and reinstall it would be the next step.

Before you crank the engine up I suggest that you replace the transmission filter. Take note of the Part Number that you remove, it might not be the correct one. Also cut it open and look for material in the pleats of the filter media.

Depending what you find in the filter, a look inside the priority valve and the steering/brake control valve might be the next step.

The filter P/N should be 1R0741 along with two O-Rings 6D9157 and 2K4472.

 

[Pralhad Birdi]

Did the screened orifice show up yet.?
Try blowing through the old one and the new one. Can you detect any difference.?
Install the new orifice, reassemble the control valve and reinstall it would be the next step.

Before you crank the engine up I suggest that you replace the transmission filter. Take note of the Part Number that you remove, it might not be the correct one. Also cut it open and look for material in the pleats of the filter media.

Depending what you find in the filter, a look inside the priority valve and the steering/brake control valve might be the next step.

The filter P/N should be 1R0741 along with two O-Rings 6D9157 and 2K4472.

So the screened orifice is not available locally, so we’ve ordered it in from America. That’s probably a few days out atm.
I’ll open up the filter and have a look, and then steering control valve as well.

Thanks

 

[Nige]

I’ll open up the filter and have a look

This VIDEO might help if you haven't done it before. Yes I know it's an engine oil filter but the principle remains the same. Squeezing the oil out of the media is key to being able to see what's lodged in it.

 

[JAJ]

Hi guys I’m a bit late to the party here so sorry if I’m asking questions that you have answered earlier and I have missed them reading though everthing.

When you tested pressures at the start did you test all the pressures and if so what were they? As I say I might have missed it but I can’t find them.

Also is this a steering clutch/brake machine or diff steer?

I think there might be a problem in the T&A doc that Nige gave you, it looks like it’s missing the pressures for power shift transmissions, I think it only has direct drive pressures. This a power shift machine you have I think?

My machine is a D6H series 2 diff steer and this same T&A manual comes up for it. They also have one listed for it that says for diff steer machines and it lists the full test pressures for power shift transmissions. I think these would apply to all power shift machines not only the diff steer ones. Nige might be able to check and make sure I’m correct on my thinking here please?
It lists pump pressure (on top of filter housing) as 495psi +-25psi high idle.
Priority pressure at 420psi low idle +-20
So your pressure is still high but maybe new pump, cold oil, blocked filter could account for a bit too.
I have attached a screen shot of the pressures I’m talking about.

Anyway a have had a very long day so I hope I haven’t misread your thread and wasted everyone’s time with a very long post that isn’t relevant. Let me know if I have and I’ll try again after some sleep.

 

[Nige]

I think there might be a problem in the T&A doc that Nige gave you,

Yes it was the wrong one. I sent him the correct one later, along with the applicable SysOp & Specifications for a machine equipped with a powershift transmission.

By the sounds of it every man & his dog had been in that transmission before the OP got turned loose on it.

 

[JAJ]

Yes it was the wrong one. I sent him the correct one later, along with the applicable SysOp & Specifications for a machine equipped with a powershift transmission.

By the sounds of it every man & his dog had been in that transmission before the OP got turned loose on it.

Ah ok awesome I thought you would have rectified it already! I just wanted to make sure it wasn’t leading the poor guy down the wrong rabbit hole.

Yeah sure sounds like the OP got left with the pineapple.

So probably won’t be just a stuck valve or something easy your thinking?

All the easy stuff checked?
Other pressures?
Cables adjusted correctly?
Doing it in all gears?

Anyway a very interesting thread to keep following. I hope he finds the issue!!

 

[Nige]

Back to the old adage - "believe nothing, trust no-one, check/measure everything at least once or preferably twice, and have all your findings & measurements cross-checked by someone else."

 

[Pralhad Birdi]

Hi guys I’m a bit late to the party here so sorry if I’m asking questions that you have answered earlier and I have missed them reading though everthing.

When you tested pressures at the start did you test all the pressures and if so what were they? As I say I might have missed it but I can’t find them.

Also is this a steering clutch/brake machine or diff steer?

I think there might be a problem in the T&A doc that Nige gave you, it looks like it’s missing the pressures for power shift transmissions, I think it only has direct drive pressures. This a power shift machine you have I think?

My machine is a D6H series 2 diff steer and this same T&A manual comes up for it. They also have one listed for it that says for diff steer machines and it lists the full test pressures for power shift transmissions. I think these would apply to all power shift machines not only the diff steer ones. Nige might be able to check and make sure I’m correct on my thinking here please?
It lists pump pressure (on top of filter housing) as 495psi +-25psi high idle.
Priority pressure at 420psi low idle +-20
So your pressure is still high but maybe new pump, cold oil, blocked filter could account for a bit too.
I have attached a screen shot of the pressures I’m talking about.

Anyway a have had a very long day so I hope I haven’t misread your thread and wasted everyone’s time with a very long post that isn’t relevant. Let me know if I have and I’ll try again after some sleep.

Just tested the pump pressure at the top of the filter housing, which I thought was oil cooler inlet pressure, and ran with it lol.
So we’ve had the oil cooler out and cleaned, we’ll change the trans filter and then once everything is back together, test the pressures again.
But like Nige said, trust nothing and no one, so I’ll just take everything apart bit by bit and hopefully find whatever gremlins are hiding in this thing!
Thank you for your post mate!

 

[Pralhad Birdi]

Yes it was the wrong one. I sent him the correct one later, along with the applicable SysOp & Specifications for a machine equipped with a powershift transmission.

By the sounds of it every man & his dog had been in that transmission before the OP got turned loose on it.

Literally every man and his dog!

 

[Pralhad Birdi]

Ah ok awesome I thought you would have rectified it already! I just wanted to make sure it wasn’t leading the poor guy down the wrong rabbit hole.

Yeah sure sounds like the OP got left with the pineapple.

So probably won’t be just a stuck valve or something easy your thinking?

All the easy stuff checked?
Other pressures?
Cables adjusted correctly?
Doing it in all gears?

Anyway a very interesting thread to keep following. I hope he finds the issue!!

So apparently the cables were changed and adjusted, but I’m going to do that again as well!
Here’s hoping!

 

[Nige]

So apparently the cables were changed and adjusted, but I’m going to do that again as well!

Specifications - Page 16 onwards. Make sure you look at the parking brake linkage as well, it is right after the control cable settings.

 

[Pralhad Birdi]

Specifications - Page 16 onwards. Make sure you look at the parking brake linkage as well, it is right after the control cable settings.

So I’ve just opened up the plate on the end of the control valve. There’s 3no. 1.4mm shims, 1no. 0.9mm shim and 4no. 0.25mm shims.
Does that seem largely normal, having so many shims in?

 

[Pralhad Birdi]

 

[Mobiltech]

That sounds about right for shims.

 

[Nige]

I know the parts manual states "Use as Required", when it comes to the shims but I would assume the quantities quoted there would be the starting point for the Test & Adjust procedure.

The quantities quoted are 1, 1, & 3 respectively. You have 3, 1, & 4.
TBH for a starting point I would suggest to remove 2 of the 1.58mm shims and just leave 1 in there. Then leave the 0.9mm and 0.26mm shims as they are right now.

In your OP you mentioned that the transmission pump had been changed. I wonder if at some point in the dim & distant past someone tried to put additional shims in the control valve to try to jack up pressures to compensate for a worn pump.?

According to the chart in the T&A document removing 2 of the 1.58mm shims behind the load piston should drop P1 Initial Pressure by around 28psi.

It shouldn't be hard to reinstall shims as necessary, but personally speaking I would prefer to start with pressures on the low side and increase them rather than start high and have to reduce them.

 

[Mobiltech]

D 5h has 1 thick 1 medium and 2 thin shims.

 

[Pralhad Birdi]

I know the parts manual states "Use as Required", when it comes to the shims but I would assume the quantities quoted there would be the starting point for the Test & Adjust procedure.

The quantities quoted are 1, 1, & 3 respectively. You have 3, 1, & 4.
TBH for a starting point I would suggest to remove 2 of the 1.58mm shims and just leave 1 in there. Then leave the 0.9mm and 0.26mm shims as they are right now.

In your OP you mentioned that the transmission pump had been changed. I wonder if at some point in the dim & distant past someone tried to put additional shims in the control valve to try to jack up pressures to compensate for a worn pump.?

According to the chart in the T&A document removing 2 of the 1.58mm shims behind the load piston should drop P1 Initial Pressure by around 28psi.

It shouldn't be hard to reinstall shims as necessary, but personally speaking I would prefer to start with pressures on the low side and increase them rather than start high and have to reduce them.

View attachment 299194

They did seem a bit excessive tbh. I’ll reduce them to what you’re saying and then measure the pressures again once I’ve put everything back.
Thanks!