D6R modulating valves repeatedly sticking

[ZacharyMartin]

There are. It’ll take me a couple of days to come up with the info because I’m away from base at the moment.

Maybe time to invest in a service manual.?

I bought the one you had linked earlier, I'll search through it and see what I find

 

[ZacharyMartin]

Here is a video with the noise it was making when parked

 

[Nige]

Do you have, or can you get hold of, an infra red temp gun.? If you can then run the machine the same way again and shoot the final drive temps with it.

If you post a photo of the dash I can identify which gauge is which for you. Best I can do when I can’t get into the system. Thinking about it you really should get hold of an Operation & Maintenance Manual which covers the basic operating & mtce tasks.

Sorry forgot you bought one already. Maybe a but of reading to familiarise yourself with gauges, warning lights, & controls might be in order.

 

[ZacharyMartin]

Do you have, or can you get hold of, an infra red temp gun.? If you can then run the machine the same way again and shoot the final drive temps with it.

If you post a photo of the dash I can identify which gauge is which for you. Best I can do when I can’t get into the system. Thinking about it you really should get hold of an Operation & Maintenance Manual which covers the basic operating & mtce tasks.

Sorry forgot you bought one already. Maybe a but of reading to familiarise yourself with gauges, warning lights, & controls might be in order.

Yeah definitely need to look through it more, I should be able to get a temp gun and run it again, but the final drives themselves weren’t overly warm, I could touch them all around no problem it was just around where the spindles mount to the frame. I’ll try and find a good spot that’ll let it slowly roll while I’m neutral and test it cold and hot and see if I feel any resistance from the brakes. I saw another forum where they mentioned doing a stall test to see if service brake will hold, it seems to work fine but if it is dragging and getting a bunch of heat in it I imagine there’s a chance it’ll slip once it’s really hot. Might try that aswell. Any thoughts to what that sound might be? Can’t imagine that’s normal

 

[Nige]

Any thoughts to what that sound might be? Can’t imagine that’s normal

Off hand no but it’s not normal IMO. If it was a hydraulic system it almost sounds like a relief valve dumping every couple of seconds.

 

[HarleyHappy]

Listening to it a few times, is it possible that it’s the filter bypass tripping?

 

[Nige]

Listening to it a few times, is it possible that it’s the filter bypass tripping?

I don’t think so, because generally a filter bypass will open and stay open if the filter plugs with debris.

 

[HarleyHappy]

Yep, fully understand that and have heard one go into bypass before but the way it’s clicking, almost sounds like it could be about to or getting ready too.
Just a thought.

 

[Nige]

A look at the filter might help to confirm or deny the possibility of the bypass valve being the source of the noise.

 

[ZacharyMartin]

I put my hand on the top of the bypass switch because I had the same thought, it seems like it’s coming from the top of the transmission, almost sound like it’s under my right joystick from the cab. Might actually pull the floor out when it starts again and see if I can physically feel it in any lines or valve blocks

 

[pittsburgh cat man]

I think if it was me I would put a couple gages on it and see if there is any fluctuations in pressure

 

[ZacharyMartin]

Well I tried to warm it up to do some tests, started throwing datalink errors I believe, serv code 30 248.02. Gauges were kicking off and on and losing gear indicator and tax. Then it started making an awful noise going into reverse. I sent the video I sent last to a mechanic buddy and he said it sounded like the priority valve kicking off and on. I think I’m gonna bite the bullet and get him to check it out and see what he thinks.

Here’s the reverse sound

And my started wiring decided it wanted to try and do some welding, something tells me this thing just wants to die lol

 

[Nige]

Any update on what you found.?

 

[ZacharyMartin]

Okay little update, the sound going into reverse was the modulating valve freaking out. It was holding about 10 psi when not engaged which was the dragging, and when shifting into reverse it would shutter and the pressure would fluctuate like crazy. I put in a new cat modulating valve and it would drop pressure to zero and not shutter. But the new valve was only getting 200 something psi when engaged when the ****** Chinese one was getting over 400. Just drained the final drives and transmission yesterday, all the fluid was disgusting, black and too shiny for my liking. Pulled the magnetic scavenging screen and it’s covered in metal and has tons of the filter media from the larger filter in it. Torque converter scavenge is missing the screen completely. Rear transmission scavenge wasn’t too bad although I did find some black pieces sitting in the bottom of the orifice that were black and flat. Sure seemed like friction material to me.

 

[ZacharyMartin]

Here’s a video of some of the material on the magnetic screen. Some small chunks the size of the ones I show that aren’t magnetic either. I don’t know how much you’d expect to see on the magnets but I would assume you’d only want a small goopy consistency of regular wear from the gear train.

 

[ZacharyMartin]

Only other thing I can think to mention is that it did feel like a little more hesitant to turn left than right as I stepped off the decelerator while already steering, but I don’t know exactly how a diff steer machine works and if it could cause that material. From what I think I know it does share the transmission fluid.

 

[Nige]

Do you know how long is it since that magnetic screen was last removed & cleaned.?

Either way I think the next step is to pull the transmission. There is far too much metal in that screen for my liking.

 

[ZacharyMartin]

I was told that the pump was removed and checked when the first replacement transmission was installed, definitely grimey enough to know it hasn’t been done in a long time. Had to break chunks of shut off the plate to remove it and with it supposedly having a new transmission 50 hours ago either someone’s lying or not taking any of the proper steps. What are your thoughts on the possibility of failing steering clutches. I’ve been looking through the diagrams and it appears there’s a stack of clutches behind the final drive. I find it hard to believe there’s been 3 bad transmissions in a row. And I’ve heard of it having previous steering related failures. I might put the old oil back in and try and do some pressure tests or see if I can feel some heat coming from one side or the other

 

[Nige]

What are your thoughts on the possibility of failing steering clutches.

It’s differential steering isn’t it.?

 

[ZacharyMartin]

It’s differential steering isn’t it.?

That’s what I keep getting told, I’m not positive how either work. But I have the vin in on the cat app and a diagram showing clutch disks behind the finals and the flanges seem to match what’s on mine.