4T40E/4T45E -Partial fluid change via check bolt?

[clembrewer]

I've an '05 Malibu Classic.

I've been reading about how this transmission has a check bolt instead of a dipstick. Also, it has been said that removing this check bolt when the engine is not running will allow 3-4 quarts of fluid to drain out of the transmission. Seeing as how this bolt is adjacent to the oil pan plug, I thought this would be a great way to do partial transmission fluid changes every OCI!

I tried it this weekend. With the front end up on Rhino Ramps, exactly 1 quart of fluid drained out of the transmission check plug.

My question to any in the know - before I go through the elaborate process of lifting up the entire car and checking while the engine is running - Is this fluid quantity correct?

Should more fluid have drained off or no?

I'm very curious to hear from someone else who has tried this.

Thanks!

 

[bxd20]

I haven't tried this, but let me make a few observations. It will be hard for you to compare your 1 qt with anyone else. The reason is, they'd need the same Rhino Ramps, and the car would have to be on the same level (or unlevel) surface. (Then more minor variations could happen due to miles on your suspension, your tire wear, what you have in the trunk, gas in tank, etc.)

Someone who's driveway was angle differently, using a different brand of ramps, might get quite a different drain than you.

I would suggest you "get it close" with the new fluid (add about 1 to 1.5 qts) , get the car as level as possible and then open the plug with the engine running. If Nothing comes out, add until you get a dribble.

 

[cousincletus]

You can drop the pan, remove and reinstall a new filter, and refill with 7.4 quarts of fluid. Don't need to do anything other than that. Your fluid will be within 1/2 quart from where it's supposed to be.

 

[JTK]

Just add the same amount you took out. I had the same setup on the 4L30E in my Isuzu Rodeo. I used to drain and fill when it was cool. Take 2qts out, put 2 in. Always worked for me.

Joel

 

[brianl703]

If you have a floor jack, jack the rear of the car up (there's a flat place where the pumpkin would be if it were a RWD car that you can jack it up with) until it's level. It might not be going too far to check that it's level with a carpenter's level! (check the transmission pan, it's a nice flat surface to place the level. Front-to-back level is probably much more important than side-to-side level).


Then I expect you'll get more fluid out of the drain plug.

In any case in order to accurately check the fluid level with the checking plug you must have the car level.

I find that the Classic has enough ground clearance to reach the oil drain plug (and the level checking plug) without using ramps or jacking it up. You may want to see if that's the case for you, too. Then as long as the car is parked on level ground you should have no problem.

 

[clembrewer]

I haven't had a chance to look yet, but if I can reach the drain plug w/out lifting the front end I'll try that. I'm just worried that the fluid may be a little low, as less drained out than I was expecting.