D6E transmission-torque converter overheating

[DanielG]

I am having problems diagnosing the cause of the torque converter or transmission overheating. I changed out the torque converter and scavenger pump thinking it was malfunctioning. But apparently that was not the problem. I have check the pump pressure and inlet and outlet pressure. All seem to be in the correct ranges. Tried stalling in 3rd gear to see it the drive shaft would move, it doesn’t. I still need to verify that the parking break is releasing all the way. Not sure how to do that. I took off the oil cooler and made sure the water jackets were not stopped up, they are clean. Is there anything else that maybe I am missing?
Any suggestions would be appreciated.

 

[BigWrench55]

What gear are you pushing in when the overheat happens? Do you have dirt rolling over the top of the blade? You can’t push dirt in 3rd gear. Also if you have dirt rolling over the top of the blade and your tracks are slipping then you will overheat the transmission. I’m not familiar with the D6E if it’s a high drive then the parking brake takes priority over the transmission. So if your park brake clutches are leaking by then it’s taking more oil from the transmission to keep the parking brake released. That will cause slippage in the clutch packs also creating overheating. Good luck and I hope this will help.

 

[DanielG]

The D6E is very similar to the D6D. It’s not a high track machine. We are not moving dirt on the current project. Clearing cedar and yopaun brush. Pushing in 1st gear as you can’t see due to the density of the brush. Tracks are not slipping at all That we can tell. The tractor operates just as it’s supposed to except for the torque converter temp gauge indicating that’s it’s getting up to 240 with the engine being 190.

 

[Mobiltech]

You need to start with pressure checks. Trans pump pressure and torque outlet pressure very important.
You could have a trans pump failing , plugged screens or something leaking in the steering and brake system
You may want to also check brake band adjustment if you suspect brake drag. Under the fuel tank at back of machine you will see two small triangle covers with 3 3/8 bolts. Under these is the adjustment screw. Tighten each one clockwise and then back off 9 or 10 clicks.
Also check that the park linkage is releasing under the seat.

 

[DanielG]

The pressure on the pump is 380 at high idle in neutral. The out put pressure is 42 at high idle stalked in 3rd gear. ( cat technical support suggested procedure to check)
I appreciate the tip on checking the brakes.
How would you go about checking for leaks in the steering or braking system?

 

[John C.]

Before I would plumb any gauges into anything I would check that the radiator was clean on both the outside fins and the inside. An infrared temp gun is cheap and the potential savings are huge. You can find them in hardware stores and cheap tool places for less than fifty bucks.

Possible sources for heat problems in torque converters can be plugged radiators, oil slugging in the torque converter housing, plugged torque converter oil coolers, excessive leakage in the torque converter itself. A bad torque converter shows up as excessive leakage between impeller, turbine and stator inside the torque converter. It will usually show up in an oil sample with very high aluminum content in the oil. The other bad news about a bad torque converter is that the transmission is usually standing on weak legs as well and should be considered for removal and rebuild.

 

[DanielG]

We put in a new radiator and have kept it clean so I don’t think that would be the issue here.
I changed out the torque converter thinking it was the problem as well as the scavenger pump. I really didn’t know how to trouble shoot it properly before it was changed. Thinking it was wasted money now. I took the oil cooler off and checked the water jackets, they are clean. I didn’t know how to check it on the oil side though.

 

[379Pete]

Bad Gauge?

 

[DanielG]

Changed it

 

[379Pete]

Probably low oil flow though the transmission oil cooler. Like someone else said, may have internal leaks somewhere upstream. Start with machine cold and stall converter for a few minutes then feel the tube from converter to cooler, should be hot the whole length of tube. Check it with machine hot too. Pretty simple problem, locating the cause, not so easy.

 

[DanielG]

Thanks I will give this a try. I also plan on removing the top cover and looking for internal leaks but am not sure what I am looking for.

 

[Nige]

First up, post a Serial Number. It makes finding information a heck of a lot easier............

Your 42psi TC Out pressure in 3rd speed stall sounds low to me (I'm used to a minimum of 60psi), but without specs to work with I'm guessing. If the Cat House gave you the procedure did they give you the specs also..?

Do you know if this tractor has had a transmission failure/repair in the recernt past..? If this was the case and the cooler was not changed I'd bet money the oil side of it is partially blocked.

 

[DanielG]

SN 2MJ01776

I have owned the tractor for 5 years and have not done anything but oil and filter changes. I don’t know if the previous owner had done any work to it. The oil was very black when I bought it but has been good with regular oil changes. (Transmission )
Is there a way to clean the oil side of the cooler?
The spec the gave me was 42 +or -5. We had 42 but it will drop to 30 in 15 or 20 seconds. Not sure if that’s normal or indicative of a problem.

 

[Nige]

TC outlet pressure should stay bang on the same value for as long as you keep the machine stalled in 3rd gear. The fact it falls is indicative of a problem.

How many hours on the machine BTW...?

There is no reliable or economical way of cleaning the oil side of a power train cooler.

Could you get into contact with the previous owner and ask about transmission repairs..?

 

[DanielG]

It has high hours I believe it’s close to 14,000. I bought the tractor from Southwest Machine in Atoka Oklahoma and not sure where they got it from. I will start by calling them to find out if they remember the transaction.

 

[Shimmy1]

SN 2MJ01776

We had 42 but it will drop to 30 in 15 or 20 seconds. Not sure if that’s normal or indicative of a problem.

Will it hold 42 for 10 sec, and then drop to 30 in the next 10 sec, or does it start dropping as soon as you begin to stall it? Will it level off at 30 and stay there, or would it continue to fall?

 

[DanielG]

It starts dropping soon after it reaches 42. It seems to level out at 30. I will verify this tomorrow.
I did not try it in any other gear except 3rd.

 

[Shimmy1]

You want to use 3rd so you don't spin the tracks.

 

[379Pete]

Thanks I will give this a try. I also plan on removing the top cover and looking for internal leaks but am not sure what I am looking for.[/QU don’t know if you checked it, but make sure the transmission magnetic screen is clean. If you pull the transmission cover and run it, if you have a leak, it’ll be obvious to you.

 

[Nige]

What he said ^^^ - look at the power train suction screen.