rmgny44

Noticed tiny bubbles on the dip stick when I checked my auto transmission fluid today. Fluid is nice clean red. Should I be worried?

DUB

I assume you checked it correctly.

The transmission needs to be HOT..thus means you need to drive it to get it hot....then...have it on level ground...in park with the engine idling.

You did not state if the level was correct.

I personally would not worry about it but I do not know how many bubbles you saw because you did not state that also. 2, 4 or 100 bubbles? Where the bubbles high on the stick at the top of the level???

DUB

rmgny44

Check was done correctly. Trans hot, level ground, in park, engine idling. Fluid was to the upper full level on the dipstick. Bubbles all through it from bottom to top.

Big2Bird

Foaming is usually caused by too low a level. Foam is NOT a good lubricant.
I do not claim to know what would cause that when full.
What fluid do you use, and any additives?

rmgny44

Fluid was changed in July 2015. Service record does not indicate what type fluid was used but the work was done by a reputable shop, the Corvette Center in Colorado Springs. 2,600 miles put on the car since the change.

rmgny44

No additives !

fishslayer143

bubbles on the stick can also be from too much fluid in the transmission. are you sure your dipstick is correct one? or sucking air around filter o-ring . Air bubbles do not lubricate.. you need to find cause

DUB

Contact who worked on it last and voice your concerns. I also can not add any more to what can be causing this carbonation of your fluid. But I do agree...I would have to find out what is causing it.

Possibly contact someone like Bowtie Overdrives and ask them and see if they may know...along with any local transmission shop in your area and get a consensus of what they all fell it is.

As like what 'fishslayer143' mentioned....Air leaking past the seal of the filter is a VERY PLAUSIBLE cause.

I assume this is a TH400..and if my memory serves me correctly..the filter is screwed in place with a thin paper gasket.

DUB

7T1vette

"Bubbles" on the dipstick are not necessarily a cause for concern. Your transmission has a vent on the main housing. When you turn the engine off, the transmission is hot. As it cools down, outside air is drawn into the main housing, and if it is moist, it can condense some droplets of water in with the oil. But, as you know, water and oil don't mix. But, that's no big deal. When the trans gets to operating temperature the next time, most of that moisture will evaporate and then the process will start all over again. No biggie.

Now, if ANTIFREEZE had gotten into the transmission oil, that would be a very big problem. Antifreeze (ethylene glycol) doesn't mix WELL with oil...but it does mix SOME. It forms a nasty emulsion which can turn into a gummy goo; bad for the engine if it happens there---equally bad for the transmission if it happens there.

But, you don't have a foamy pick emulsion going on--you just have some water droplets on your dipstick. Situation "normal".

usmilret

Excessive bubbles can be a sign of an internal leak.

rmgny44

Thanks for all the replies. I found a new shop in town that comes highly recommended by the local Corvette Association. The car is going in next Tuesday for a general check-up!

7T1vette

The only possibility of an "internal leak" would be from the engine's cooling system (radiator tank cooler for the tranny). But, the transmission's cooling lines (that run from the trans to the radiator) have much higher pressure on them then what is in the radiator; so the "leak" would be trans fluid into the engine's coolant/radiator.

Also, if you have anything other than plain ol' water in the cooling system, you wouldn't see ONLY water beads on the dipstick.

rmgny44

Thanks for all the replies! It turned out to be too much fluid in the tranny. All is good again!

cardo0

Thx for the follow up. This can help us all.

fishslayer143

now, where did I see that...hmmmm.... gad you got it resolved.. now enjoy

rmgny44

Good call Fishslayer!

vbgod1

If you want to see this, Google 'Stawberry Milkshake' on Toyota 4Runners. I managed to save it with a 6 gallon flush of coolant and a 8 gallon flush of Trans fluid, a new radiator, then having a shop power flush both systems. Don't want to ever see this again.

mikem350

Coolant in trans oil is a sure way to destroy the transmission clutches.

vbgod, you are very lucky!