1994 Explorer trans leaking into oil

[Mike G.]

Here is a wierd one.

My daughters 94 Explorer 4.0L leaks about 3 pints of tranny fluid every week to 10 days, and as near as I can tell, it is getting into the oil.

The oil level gradually rises about the same amount that the tranny leaks.

I'm stumped.

Any ideas? Id appreciate it.

Mike

[Mike G.]

I know one of you has a guess or something!

The other wierd part is that oil doesn't leak back into the tranny.

Please help so I don't spend a bunch of money taking it to a shop.

[shorod]

When you say the tranny leaks, do you just mean the tranny level drops, or does it actually leak to the outside (puddle on ground)? How do you know it's leaking 3 pints and that the engine oil is increasing about 3 pints? The transmission holds a lot more oil than the engine, so going by the level on the dipstick for the two is not accurate.

There's no passage between the transmission and the engine oil system. None. Unless someone has mis-routed transmission and engine oil cooler assemblies.

Does the engine oil have a normal appearance to it, just a higher level?

The more details you can provide the better chance someone will have for helping you out.

-Rod

[way2old]

If it has a modulator valve, check it to see if it is sucking transmission fluid through the vacuum line.

[Mike G.]

Originally Posted by shorod

When you say the tranny leaks, do you just mean the tranny level drops, or does it actually leak to the outside (puddle on ground)? How do you know it's leaking 3 pints and that the engine oil is increasing about 3 pints? The transmission holds a lot more oil than the engine, so going by the level on the dipstick for the two is not accurate.

There's no passage between the transmission and the engine oil system. None. Unless someone has mis-routed transmission and engine oil cooler assemblies.

Does the engine oil have a normal appearance to it, just a higher level?

The more details you can provide the better chance someone will have for helping you out.

-Rod

Tranny fluid does NOT leak on the ground. it is NOT leaking from the pan; I changed the filter and used RTV silicone. No leaks from there, and none visible anywhere else.

The tranny loses about 3-4 pints (1 quart) a week or so, and as I stated above, the oil level in the engine increases by the same amount. I tracked this a couple of months ago, and I'm about to empty the oil pan again this weekend, as it is over full. I measured the amount of oil I drained from the pan last time, and it is over full by the same amount of tranny fluid I have added.

I have changed the rubber transmission cooler lines, and followed the steel lines back to the transmission. No problems there. It has a seperate transmission cooler, so no misrouted lines.

The engine oil does have normal color. That is what initally got me wondering.

Thanks.

[way2old]

There is a little vacuum valve on the side of the transmission. The hoses should be dry inside. If there is transmission fluid in it, replace the little valve.

[Mike G.]

Originally Posted by way2old

There is a little vacuum valve on the side of the transmission. The hoses should be dry inside. If there is transmission fluid in it, replace the little valve.

Thank you.