corvettelvr73

About every 3000 miles when I change the oil I check the tranny level (with the engine running and in nuetral) after about 10-15 miles of normal driving. Every time it is about a pint or so low. Everytime i add a little and check it again untill it is between the hot marks. What could be happining with the oil. It doesnt drip a drop and the underside of the runner is clean (no oil).

gwhayduke

How long has this been going on?

Could it be that the last time you swapped out the tranny fluid, you didn't get the torque converter filled up?

What's the underside of the tranny and vehicle look like? Any sign of fluid being thrown?

mt_goat

The only thing I can think of is maybe it's leaking into the transfer case. Have you also checked the level in it? They both use ATF and are integraded together with I believe just a seal between them. I'm guessing that the reason Toyota uses ATF in the auto tranny transfer case is just for that reason (the possibilty of fluid sharing at some point).

corvettelvr73

It has happened since ive had it for a year. But it really never goes below 1 pint or so. Even if i go 6000 miles it only looses a little bit. The underside is completely clean of oil. That is the first thing i checked. I havent checked the transfer case yet though.

TechWrench

One possibility is the radiator. It is not that unusual for the coil in the bottom of the radiator to develop an internal leak. If this happens, trans fluid will slowly leak into the radiator and mix with the water/anti-freeze. If this happens, you will usually see a frothy pink/red mix in the overflow bottle. If that isn't it, then you might be blowing some out of the breather vent when the trans gets hot. This could explain why you only loose about a pint before the loss stops.

AgRunner06

Well I'm pretty sure you are supposed to check the tranny fluid with the vehicle in Park. So that could account for your different level. If you keep adding too much to it then it is possible that it is coming out of the breather.

corvettelvr73

I wasnt sure about checking it in park or neutral so i checked it in both numerous times and it is always the same level. WHere is that breather at anyway?

shovelhead

Park and neutral are essentially the same gear (or lack there of ) with park having a pawl that engages the output shaft through mechanical connectors

mt_goat

That's a good point about the radiator, since the ATF cooler is incorperated with the radiator.

I think the breather is on top of the tranny, but I would expect to see an oily mess somewhere if that was blowing ATF out of it.