2003 NV5600 gear shift leak

[rjgamfarm]

I noticed a couple oil spots on the garage floor, so i washed the underside off and found the leak was at the top of the transmission. Next I pulled the console out and lifted the shift cover off, I saw the oil and thought loose bolts, but could only get 1/4 turn max on the 4 torx heads.

I wiped and blew the extra oil away and let the truck run for a few minutes.

The oil is coming up through the center of the tower where the gear shift goes through. It bubbles as it comes up then seeps down the rear side of the tower assembly. The fluid isn't warm at all and the truck is just sitting idling at normal RPM



The breather is free and clear with no obstructions or kinks in the tube. I estimate that I am down at least 2 liters of fluid.



#1 Has anybody seen this problem before? I have looked back on the site here and only can see gasket or loose bolt issues. I have never had the shifter off. I have 180,000 km, everything is stock on my truck



#2 How much damage could of been done with 2 quarts missing? Lately I have mostly done highway driving with no trailers or towing.



Any help would be greatly appreciated.



Rob Johnson

 

[jelag]

I've had several of these trucks with lots of miles. . I've not seen this leak... these transmissions seems to like an extra quart of lube oil. But I'm guessing you've caught it in time...

You say your down at least 2 liters and later say 2 quarts... . have you actually re-filled the transmission and know how much you were actually down. .

 

[Prairie Dog]

I remember one other case of this here. The dealer told the owner the case was rusted through (it wasn't ). Owner sent if off to Standard transmission if I remember correctly, and they went through it and fixed the leak but I don't know what they did exactly.
You might give ST a call and ask them directly if nobody else here knows more.

 

[rjgamfarm]

Sorry. I have not re-filled it yet, the fluid is about about an inch and a half below the filler plug. I'm guessing that's around 2 liters/quarts low.
I've been using one of our other farm trucks to drive around with until I figure out the issue.
My dealership has never seen this leak, same as our farm mechanic who worked at a dealership as the "diesel guy" for 15 years.

It's got everyone stumped

 

[blacksheepdiesel]

You say the breather is free and clear. The only way I can imagine bubbles being forced out of the top of the transmission is because of pressure buildup inside the transmission. Have you installed a new breather or swapped one from a truck that does not have this symptom?

Godspeed,
Trent

 

[rjgamfarm]

You say the breather is free and clear. The only way I can imagine bubbles being forced out of the top of the transmission is because of pressure buildup inside the transmission. Have you installed a new breather or swapped one from a truck that does not have this symptom?



Godspeed,

Trent

Thanks Trent



The breather was all gunked up. I took the air hose and blew all around and under it. It appears to have solved the problem. I'm now waiting for the MTF to show up so i can swap out the fluid. How many extra liters should I add?

 

[blacksheepdiesel]

Glad it worked. Total of 7 qts.

Godspeed,
Trent