2005 Chevy Malibu Sealed System On Transmission

I want to add some type of transmission additive to the transmission. I have two questions,

First, this is a sealed system, however you can still twist off this cap under the hood and it looks like pour something into the transmission. From the best of my knowledge, on a sealed system, the car has to be cranked to even check, and or add transmission fluid.

Second question is, is there anything for high mileage cars that works as a stop leak that I can pour into this?

I don’t want to be screwing up my transmission, I don’t even know if its possible to add stuff like that to a sealed system on your own.

Thanks for the help!

The transmission does have a screw cap in the engine compartment. The level is checked from a plug under the car, while it is, level, running and fully warmed up. Hard to do without a lift, or at least 4 jack stands.

Or course you can add to a "sealed " system because there really is no such thing. You should not over fill the trans, however, so any additive you pour in may overfill thentrans.

But why do you think you need to add something?

I have a minor transmission fluid leak.

Stuff like Trans Medic might work but depending on where the leak is, it might be an easy fix. Drive axle leaks are easy to repair. An input shaft leak is another matter. In any event, you likely will need to drain a quart out to pour a quart in.

Yeah Im thinking I’m just gonna go pay to have it checked and give it to a mechanic to add. I don’t like messing with the transmission on this thing at all. First sealed system I’ve ever had.

Again… not sealed. There is a filler cap on it and a level port.

I’ve had success doing a few drain/refills on my sisters Cruze by making sure tranny is warm (like, for real warm 185 sitting in stop and go
warm), parking on a level surface, turning the wheel in a way that allows maximum access, and removing the fill level access plug. It takes just a square 3/8 inch socket driver if I recall. Just take the cap off and fill with Dexron VI until it starts to trickle out. It is worth a try. Just make sure its nice and warm. Obviously, if you remove the plug and stuff starts to trickle out just immediately replace the plug.

Sorry. Thanks!

Thank you!