Leaking oil near transmission oil pan

[esolejoel]

Hello! I’m having a pretty bad leak near the transmission pan, it seems to have leaked about 200ml if fluid. The colour of the oil is light brown/clear. Any ideas as to where this oil is coming from?(see pictures) And a possible DIY fix, thank you in advance. It looks like it’s coming from the drive shaft, above the transmission pan, if that helps with identifying a solution.

 

[220629]

I can't offer much.

NAG1 transmission fluid does turn from red to a brown(ish) color as service time increases. So it may very well be transmission fluid.

The electrical connector body has a history of leaking. You might check to see if the fluid is coming from there, but being carried/moved to drip off other areas.

vic

 

[esolejoel]

Okay, because I just had the transmission fluid changed about a week ago. I’ll check if the fluid is coming from the electrical connector forsure, thanks Vic

 

[220629]

Changed a week ago? The new fluid should still be red.

I don't know the implication of that.

Be certain to check that the seal is properly in place and the pan clamp blocks are properly installed.

Have you touched the drips to a tissue? Sometimes that makes oil spill details a bit easier to see.

vic

 

[koenb]

Changed a week ago? The new fluid should still be red.
I don't know the implication of that.

Assuming the fluid that was used was red then yes... Eeek.
Coolant? I know the zerex GO5 is a tan-ish brown color.... Should be able to rub the liquid between your fingers and determine if oil or coolant or smell it. Coolant is watery and has a sweetish smell. ATF has a distinct oily pungent smell to it.
An odd place for coolant, If that is the case I'd look upstream at the EGR/Aux pump/heater core coolant hoses. It could run down the top of the trans and potentially reach that area before dripping.

Also, a good first step would be grabbing a grungy scrub brush and some brake cleaner and clean all the residual grunge and oil from that area. It will help identify the leak.

 

[Nautamaran]

Who changed it, and did they measure the fluid level HOT? If they filled and measured it cold you may be looking at hot overflow? The NAG1 doesn’t like being over filled. This causes foaming of the fluid, which can then bubble out the vent on top of the casing. Also possible the torque converter drain plug is leaking?

-dave

 

[220629]

Assuming the fluid that was used was red then yes... Eeek.
...

Good point. To my knowledge the MB approved fluids are red color.

Another factor is whether the service included a TC drain as Nautamaran mentioned. A pan drain only could leave enough older brown color fluid to quickly dilute the red color of the new fluid.

vic

 

[Midwestdrifter]

That leak area looks like it might be the output shaft seal. Can you take a look around that area? Is there excessive free play at the output flange?

Confirm the fluid level is correct. Overfilled transmissions have been known to leak from odd places.

If the output shaft doesn't have excessive play, but the seal is leaking, you can replace the seal in situ. A socket is needed for the nut (and a new nut). Pry the seal out and tap in a new one.

 

[esolejoel]

I ran the van for a couple minutes and about 10 minutes in, it started leaking from this 1/4” tube above the transmission (pictures attached). It smells oily maybe even gas like. Any ideas as to where this tube is supposed to be connected ?

 

[Midwestdrifter]

Does it run to the back of the engine head? If so that's the drain for the injector valley. That would be fuel or possibly oil coming out.

 

[esolejoel]

Yeah, it does run to the back of the engine

 

[Midwestdrifter]

Okay, then you need to remove the black plastic cover over the injectors.

 

[esolejoel]

Okay, then you need to remove the black plastic cover over the injectors.

Okay Done

 

[Midwestdrifter]

Do you see leaking fuel or oil?

 

[esolejoel]

Yes I believe it’s leaking fuel, there’s a puddle of fuel in each bay, with the biggest puddle in the back and smallest in the front

 

[Midwestdrifter]

Common leaks are the rubber return lines. Warning, high pressure leaks from the metal lines can cut through skin and kill.

 

[esolejoel]

how would you test it ?

 

[Midwestdrifter]

Idle the engine and look for the leak. Use a piece of cardboard to look for leaks at the high pressure lines. Typically the leaks are on the low pressure side, the tee fittings on top of the injectors.

 

[esolejoel]

So it looks like one of the cover mount threads is cracked, probably from to much torque when putting the engine cover back on, (Previous owners doing). Might have to be welded shut, or maybe a putty can cover up the hole.

 

[220629]

So it looks like one of the cover mount threads is cracked, probably from to much torque when putting the engine cover back on, (Previous owners doing). Might have to be welded shut, or maybe a putty can cover up the hole.

Did someone say JB Weld?
It's not expensive to try. Everything needs to be EXTREMELY clean before application.

It must have taken a ham handed installer to crack the aluminum while installing the plastic cover.

vic