D6H ll Series 2 Differential Steer

[PWR]

Have a D6H ll with differential steer. Have 10,000 hours on machine. Still in good shape but it seems like it is moving much slower in forward 1st gear. Is there something in the transmission or torque converter that would cause the tractor to move slower than normal. I have been running machine since new. Last few years we do not use it as much as we used to. I keep wondering if it is just me, but is just seems like it goes much slower in forward 1st gear.

 

[Nige]

Is the problem happening in both forward and reverse..?
When was the last time the transmission oil & filters were changed..? Did the oil smell burned..?
Have you removed the screens from the bottom of the torque converter and transmission housings to check for any contamination..?

 

[PWR]

Nige it does it in forward. Moves good in reverse. Changed oil and filters, checked everything about 2000 hours ago. Put in Cat reman engine at that time. Should have probably had the torque converter rebuilt at that time just for good measure. The oil has never smelled burned. It is still clean and smells okay.

 

[Nige]

Did the problem start (or at least since you noticed it) since you did the most recent transmission oil change..?
When you say you checked everything do you mean the checked the screens or did an oil & filter change..? Just FYI the recommended oil & filter change interval on that transmission system is every 500 hours/3months for the filter & every 1000 hours/6 months for the oil.

Personally as a next step I would drop the screens on both the transmission case and the converter and see what comes out of them before fixating on the converter. Your symptoms give every indication that the transmission forward direction clutch could be on the way out. If you find significant quantities of clutch facing material in the screen that would be confirmation. Even if you didn't find loads of clutch plate in the screen I would think a pressure test of the transmission would be the next step.

 

[PWR]

Did the problem start (or at least since you noticed it) since you did the most recent transmission oil change..?
When you say you checked everything do you mean the checked the screens or did an oil & filter change..? Just FYI the recommended oil & filter change interval on that transmission system is every 500 hours/3months for the filter & every 1000 hours/6 months for the oil.

Personally as a next step I would drop the screens on both the transmission case and the converter and see what comes out of them before fixating on the converter. Your symptoms give every indication that the transmission forward direction clutch could be on the way out. If you find significant quantities of clutch facing material in the screen that would be confirmation. Even if you didn't find loads of clutch plate in the screen I would think a pressure test of the transmission would be the next step.

No excuse for not changing but we do not use machine real often and it get neglected. Soon as we get it to shop I will check the screen in the magnetic filter. Will line up pressure check.

One more question on different machine. Cat 130G. Bought it used. Old military grader. No history on it but it does not look like it has been over used or abused. After we cleaned out area under engine and transmission we have found a lot of oil leaking under the machine. Can not see under machine good enough to determine where oil is coming from. It appears to be transmission or hydraulic oil. We have run it and brought in back in shop and a good bit of oil leaks out on the floor. Tried looking under transmission and torque converter with mirror but hard to tell source of oil. Looks like oil may be coming from where they are joined together. Do you know of any way to find leak without removing transmission and torque converter? Is it common for that machine to leak where the torque and transmission are bolted together?

Will keep you posted on D6H when we do some more checking.
Thanks for your help.

 

[Leroyb]

Good time to but a bore scope with a camera on it. Some even have videos. They have lights on them, somypu can see in places you couldn't see on these machines. Even harbor freight has one that's cheaper. But it works

 

[PWR]

Ordered camera from Harbor Freight

 

[Leroyb]

I haven't really worked on a 130, I did work on plenty of 140, 14, 16. if that 130 is similiar their is a differential lock on top of the differential case. under the oil pan. It's an electrical solenoid. has one wire attached to it. and one hydraulic hose. You can take it off and change the O-ring on the mounting . that's where these motor graders generally leak from.

 

[PWR]

Thanks Leroyb. I hope the 130 is similar to the 140. Can the solenoid be removed and repaired without having to pull transmission out? I am going to check service manual and see what I can come up with. With our limited investigation I did not see a solenoid. Are you referring to it being under the oil pan of the engine?

 

[Nige]

If you gave a S/No of the grader (or at least the prefix) I might be able to come up with an illustration showing exactly where the diff lock valve is located. The best way I can describe it is that the differential case is mounted to the rear axle housing which itself is located directly below the engine oil pan. The differential lock control is installed on top of the differential housing. The control can be removed from the housing without any other component removal AFAIK but it will be a total PITA because it will need a 3ft tall triple-jointed dwarf to get in there to work on it.......

 

[PWR]

Nige the serial number is 74V2065. Is the diff lock switch on the lower right side of the instrument panel? I assume with a solenoid it is electrical. That is the only thing I found that looked like it might be it. Just wanted to be sure I had a differential lock.
Do not have short midget but my middle son/partner is an impulse driven bull in a china closet. Reckon he will work?

 

[Nige]

This is what the diff lock solenoid valve looks like. The o-rings that might well be leaking are the ones in the passages marked 11 & 12.

 

[PWR]

Finally got back on grader leak. Did not look like the diff lock solenoid is leaking but we did find a little plug right above it that appeared to be the problem.
It was very loose and had oil in the area. Tightened it with a 3/8 inch drive. Cleaned everything and are going to give it a try. Sometimes it is the simple things that get you. Just hard to see in that area.
If we do need to remove the diff lock solenoid do you just remove the bolts and slide it out? I assume it just lets the oil flow through it. We did find the wire was unplugged. Plugged it in and it seems to be working. The light on the dash is on when it is in the unlock position. I think it has been operating in lock position.
Thanks Nige and Leroyb for your help. I really appreciate it.

 

[Nige]

Finally got back on grader leak. Did not look like the diff lock solenoid is leaking but we did find a little plug right above it that appeared to be the problem.
It was very loose and had oil in the area. Tightened it with a 3/8 inch drive. Cleaned everything and are going to give it a try. Sometimes it is the simple things that get you. Just hard to see in that area..

Which brings us back to my comment regarding the requirement for a triple-jointed midget to get in there .......

If we do need to remove the diff lock solenoid do you just remove the bolts and slide it out? I assume it just lets the oil flow through it. We did find the wire was unplugged. Plugged it in and it seems to be working. The light on the dash is on when it is in the unlock position. I think it has been operating in lock position.

You are correct, the diff lock valve just controls the flow of oil. If you need to replace the 2 o-rings the valve just unbolts and slides out. If the wire to the valve was disconnected then the diff lock was on permanently. A good job you found that otherwise you could have had really expensive diff problems in the future.

 

[DARO]

Nige is there a part number for a triple jointed midget? Sure would come in handy.

 

[CDUB]

Nige is there a part number for a triple jointed midget? Sure would come in handy.

Those are on a different forum.