d6h series ii

[4730]

have a 1989 d6h and the darn thing works perfect for an hour or more but after that the trans temperature get real hot. it pushes great till oil heats then things start to happen . when your switching from forward to reverse sometimes you put leaver in gear and it will do nothing? we have changed transmission filter and cleaned screens and the screen was full of rust but cleaned put together but no difference.

 

[gary808]

Did u check the oil cooler ? I have seen a trans cooler get plugged up with gunk on the water side and not cool.

 

[4730]

with a heat gun the cooler does seem to work but that being said I have not taken it apart . I did clean suction screen for transmission pump and it was dirty. there suppose to be a screen on TC but I have not found we're it is

 

[gary808]

It's worth checking. I've seen one plugged up with sludge and silicone from repairs ro the water system. Caused the trans to heat up.

 

[4730]

so getting at tearing apart cat and this is the valve that lets oil to trans oil cooler does it matter that it looks like this?

 

[rmllarue91]

How hot is it getting does brake pedal come all the way back up?

 

[4730]

ya brake comes all way up. the transmission oil will go to 210 easy after hour of working it . engine temp stays at 170

 

[rmllarue91]

Yeah that's hot need to take some pressures to check oil flows check temp on trans cool from back to front and water temp going in and out will give you a good idea of cooler efficiency. Would to a stall test put blade into a pile with brake on rev machine in high gear and watch torque out let pressure.

 

[4730]

well that was fun taking off god what a job ! Don't think it was ever taken off before plugged solid I think . coolant side is clean . oil side is plugged solid is say I blew it out a bit before picture . can a guy press that cooler out?

 

[rmllarue91]

Lots of rust in system drain bevel gear case and flush try off road equipment or costex tractor parts for a cooler

 

[Nige]

It would cost more to attempt to clean it than a replacement is worth. Use the old one for a boat anchor and find a replacement from somewhere.

 

[4730]

going to put new one in 770 bucks not to bad it's suck a bear to get out and in it better be new

 

[4730]

so I did try to blow air through oil part and it would go through at all so i am hopping that is a major part of what was causing the heating problem

 

[4730]

wouldn't go through.

 

[4730]

picture didn't go through before sorry

 

[gary808]

Looks ugly in there, hope that's the root of your problems.
What's the service history on the trans oil and filters? The cooler valve looked pretty scorn up in the early pics.

 

[4730]

we bought at a rb sale so guess we didn't luck out this time but hopefully can get it running properly learning lots about dozer that forsure

 

[4730]

is there any kind of cleaner to put in oil to clean whole system? Was even thinking about putting diesel in oil and run for a bit no load of course and change it couple times.

 

[gary808]

Not sure about diesel, haven't tried it personally. When we did our d7 we did a few cans of hydra tune from seafoam with new filters and ran it for a few hours to warm it up then drained it. It was milky from a bad trans cooler.
After that we drained and put new cat trans oil and filters.
The oils been crystal clear after that.

 

[d9gdon]

I have run straight diesel in a crankcase for a couple of minutes on 2 or 3 pieces of equipment to flush them before without any trouble. Drain and refill with oil. I usually only ran them a couple of hours and then changed the oil yet again and good to go then.

Let's just say that two of them went for a swim as the reason for flushing.