Transmission fluid reading is wonky (increasing)
 

Wonky = Not right.

There is something not right with my transmission fluid dip stick readings.

I found 2 months ago that my fluid was high. (see previous post: "What really happens when the transmission has too much fluid (oil) in it?") I ended up draining down the fluid to the correct level and have experienced no adverse side effects. After the drain down I checked the fluid multiple times - while the engine was warm and after doing and hour of driving - and the fluid level was inside the Hot mark range as prescribed.

Recently I checked my transmission fluid and it is way over the high marks.

I checked it on different days with the engine warmed and after driving and even cold after sitting over night and it is consistently over the hot level up over the twist in the dip stick.

It is my understanding the dip stick goes into the fluid pan of the transmission. Is that correct? Can it hang up on something?

How could the fluid level go UP if not due to the heat of the fluid ?!!

What might be causing a fluctuation in transmission fluid level readings on the dip stick?

Thank you

There is only one way to check tranny fluid.....the right procedure for checking the fluid level is to warm up the transmission by driving, park on a level spot, leave engine running, set emergency brake, move the shift lever from Park through all the gears and back (letting each gear engage), leave in Park, pull dipstick and wipe clean with fingers, then reinsert, pull again and read.

Your response makes me suspect I have the wrong idea about how the trans fluid level changes depending on how it is measured.

I was of the assumption that the fluid expanded when Hot and that is what raised the level.
But based on warming the engine and coating all the gears that would take fluid out of the pan - lowering the level.

Would the fluid taken out to coat the gears still be compensated for by fluid expansion to raise the fluid level?

There is an inch on the trans fluid dip stick between Cold and Hot. That strikes me as a lot of difference.

What exactly does the dip stick fit into when it measures fluid level?

Also - how the fluid is measured does not account for why the level is rising without adding fluid - Hot, Cold or otherwise.

That is my point. Because of the expansion of fluid during operating range, you only check it the one way. Use that check to adjust fluid level and ignore all other fluid readings. Unless its frothy or smells burnt, you should almost never need to add tranny fluid.
I would recommend taking it to a tranny shop for a new fluid and filter service if it has not been done in the last 45000 miles. Then you have a good place to start. Its worth the 120 bucks or so.....

No one is answering the questions -

Why doesn't the transmission fluid level change between Cold and Hot readings?
or
What could make the fluid level go UP if not due to the heat of the fluid?

There are just way too many factors to give you accurate answers..


The trans fluid travels through the torque converter and trans cooler (if you have one). It all depends on how much fluid settles in those places and how much settles in the pan... I will guess that this varies based on driving/hot/cold/incline etc.


Its not as simple as checking your engine oil, where most of it drains back into the pan.

So is this another case of chevrolet designers on crack?
They design a fluid level check that can't possibly work because the fluid never settles in the same place twice. (?)

It sounds like I'm stuck with just making sure the dip stick is wet and the transmission has not burnt up "yet" as a service check.

......

If its "increasing" in level you may need to check that your not getting anti-freeze into the transmission from a leaking transmission cooler...

Would that not show right away with foamy strawberry coloured fluid on the dipstick, and also fluid in the coolant overflow reservoir?