[StarCaller]

changed the differential & tranny fluids to mobil1 today.
now I think I might have overfilled the tranny:
I jacked the drivers side up & opened the fill hole to see how much is in. the old fluid was slightly dripping out.
then I drained the whole thing through the drain plug & refilled it through the fill hole that it just started dripping again. so far so good...
what makes me nervous now, I put the old fluids in an empty 5 quarts pennzoil container, & the container didn't even get full to the brim.
the differential took about 1.6 quarts & the tranny around 4½, so I think the container should have been full to the top.
but then, on the other hand, if I put just enough in to start it dripping again, how could it be overfilled?

btw, didn't notice any difference while driving; neither with the tranny nor with the differential...

edit: was reading Xman's post here
http://www.gtoforum.com/showthread.php?t=6731
& the one from teamgs here
http://www.gtoforum.com/showthread.php?t=8195

they all put in 4.6 quarts, in opposite to gtore62's 3.8 .......
http://www.ls1gto.com/forums/showthread.php?t=60837

& now I'm getting really confused...

 

[Subdriver]

Couple thoughts and questions.

According to the AMSOIL Online Product Application Guide the 2005 GTO transmission takes 4.65 quarts and the diff 1.7 quarts.

Is it possible the 5 quart container can hold more than 5 quarts? Do you have another one you can use to pour a known quantity in?

It seems to me that if the fill hole is on the driver's side (same as on my Vette) and you are jacking up the driver's side, your fluid level won't be at the correct spot. Doesn't the car have to be level to determine the fill level at the fill hole? If the drain hole isn't at the lowest point then all the old fluid wouldn't come out. This may happen if the car is on a slope, even a small one.

 

[StarCaller]

I tried to explain it further in this post here
http://www.ls1gto.com/forums/showthread.php?t=85264

so would you suggest to just level the car, open the fill plug & let it drain til it's even with the hole?

 

[Subdriver]

I tried to explain it further in this post here
http://www.ls1gto.com/forums/showthread.php?t=85264

so would you suggest to just level the car, open the fill plug & let it drain til it's even with the hole?

That is the procedure for the Corvette, but I have a service manual for that. Can't confirm that is correct for the GTO. I was hoping someone more knowledgeable might chime in for you.

 

[Xman]

The amount of fluild the GTO manual transmission requires was a big issue that went round and round back in late 2004 and early 2005. The GTO M6 takes 4.6 quarts of fluid. How much drained out of yours is not realavant. If you jacked the car up on the driver's side only and used the fill plug, you still have to measure the amount of fluid inserted just like you would if you filled it from the back-up switch on the passenger side with the car level. If you refilled the tranny with 4.6 quarts (plus or minus a couple ounces) you will be fine.

 

[StarCaller]

yep, that's what I did, put in 4.6 quarts.
but, actually I expected to feel some difference.....

 

[Subdriver]

... How much drained out of yours is not realavant. ...

Its not relevant if he got all the fluid out, but if he didn't get all the fluid out then it is relevant as he may have too much fluid in there now. For example, if he had 4.6, drained 3.6, then added 4.6, he now has 5.6 in the tranny. Not sure how likely this is, but if the drain plug wasn't the low point in the tranny when he drained (such as if the car isn't level) then I'd think it would be possible to have some residual fluid in the tranny.