Is it possible to over fill the automatic trans?
Thread Starter
Racer
Joined: Mar 2019
Posts: 302
Likes: 51
From: Northern NV
Is it possible to over fill the automatic trans?
Curious if it can be done. I thought they are filled at a hole on the top side of the tranny and when the ATF runs out it is full. So i dont think it can be overfilled.
Le Mans Master
Joined: May 2006
Posts: 5,747
Likes: 224
From: Hillsboro Oregon
Thread Starter
Racer
Joined: Mar 2019
Posts: 302
Likes: 51
From: Northern NV
So you cant overfill it then. you could under fill it if you did it cold but the fact that the fluid runs out of the fill hole when it is full means you cant over fill it. Right?
I ask because when a brought home the car after I bought it and parked it in the driveway, the next morning there was a small amount of ATF on the ground. The same the next day after I drove it. The outside temps were around 70 and the trans temp was up to 210 (a little high for me). I cleaned up the area and put a drip pan under it. No more drips. So I took it back to the place I bought it from and they took it to a mechanic. It did not drip again the morning I dropped it of. The mechanic cleaned up the area and did not observe any other drips. The mechanic thinks the trans was over filled and the ATF found a way out? Not sure I buy it. I drove it a bit yesterday and could not get the trans above 185 deg. But this morning no drops on the ground or under the car that I could see.
I planned to take it to a local trans shop Monday to have the trans drained, filter replaced and refilled. I will have that mechanic take a closer look at that time also.
I ask because when a brought home the car after I bought it and parked it in the driveway, the next morning there was a small amount of ATF on the ground. The same the next day after I drove it. The outside temps were around 70 and the trans temp was up to 210 (a little high for me). I cleaned up the area and put a drip pan under it. No more drips. So I took it back to the place I bought it from and they took it to a mechanic. It did not drip again the morning I dropped it of. The mechanic cleaned up the area and did not observe any other drips. The mechanic thinks the trans was over filled and the ATF found a way out? Not sure I buy it. I drove it a bit yesterday and could not get the trans above 185 deg. But this morning no drops on the ground or under the car that I could see.
I planned to take it to a local trans shop Monday to have the trans drained, filter replaced and refilled. I will have that mechanic take a closer look at that time also.
Le Mans Master
Joined: Mar 2006
Posts: 5,775
Likes: 585
From: Texas
So you cant overfill it then. you could under fill it if you did it cold but the fact that the fluid runs out of the fill hole when it is full means you cant over fill it. Right?
I ask because when a brought home the car after I bought it and parked it in the driveway, the next morning there was a small amount of ATF on the ground. The same the next day after I drove it. The outside temps were around 70 and the trans temp was up to 210 (a little high for me). I cleaned up the area and put a drip pan under it. No more drips. So I took it back to the place I bought it from and they took it to a mechanic. It did not drip again the morning I dropped it of. The mechanic cleaned up the area and did not observe any other drips. The mechanic thinks the trans was over filled and the ATF found a way out? Not sure I buy it. I drove it a bit yesterday and could not get the trans above 185 deg. But this morning no drops on the ground or under the car that I could see.
I planned to take it to a local trans shop Monday to have the trans drained, filter replaced and refilled. I will have that mechanic take a closer look at that time also.
I ask because when a brought home the car after I bought it and parked it in the driveway, the next morning there was a small amount of ATF on the ground. The same the next day after I drove it. The outside temps were around 70 and the trans temp was up to 210 (a little high for me). I cleaned up the area and put a drip pan under it. No more drips. So I took it back to the place I bought it from and they took it to a mechanic. It did not drip again the morning I dropped it of. The mechanic cleaned up the area and did not observe any other drips. The mechanic thinks the trans was over filled and the ATF found a way out? Not sure I buy it. I drove it a bit yesterday and could not get the trans above 185 deg. But this morning no drops on the ground or under the car that I could see.
I planned to take it to a local trans shop Monday to have the trans drained, filter replaced and refilled. I will have that mechanic take a closer look at that time also.
Thread Starter
Racer
Joined: Mar 2019
Posts: 302
Likes: 51
From: Northern NV
That's a possibility. I am not driving it until I take it to get the trans serviced. Going to get the Diff fluid drained and refilled also.
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Its just about IMPOSSIBLE to over fill the A4if you follow the service manual procedures to drain and fill. Its VERY POSSIBLE to under fill it..
To correctly fill it, you have to fully warm the engine drivetrain put the car level on a lift "CAR LEVEL",
WITH THE ENGINE RUNNING remove the fill plug on the drivers side of the trans. You add fluid till it runs out of the fill hole. Reinstall the plug "WHILE THE ENGINE IS RUNNING!!!".
IF,,,,,,, SOMEONE REMOVES the plug without the engine running, the trans will puke out a LOT of the required fluid fill and it will be low enough to damage the trans if operated for a long period of time.
I guess if you lifted the car at a steep angle from the drivers side, you COULD force in more than it needs but, that's about it.
BC
To correctly fill it, you have to fully warm the engine drivetrain put the car level on a lift "CAR LEVEL",
WITH THE ENGINE RUNNING remove the fill plug on the drivers side of the trans. You add fluid till it runs out of the fill hole. Reinstall the plug "WHILE THE ENGINE IS RUNNING!!!".
IF,,,,,,, SOMEONE REMOVES the plug without the engine running, the trans will puke out a LOT of the required fluid fill and it will be low enough to damage the trans if operated for a long period of time.
I guess if you lifted the car at a steep angle from the drivers side, you COULD force in more than it needs but, that's about it.
BC
Thread Starter
Racer
Joined: Mar 2019
Posts: 302
Likes: 51
From: Northern NV
Its just about IMPOSSIBLE to over fill the A4if you follow the service manual procedures to drain and fill. Its VERY POSSIBLE to under fill it..
To correctly fill it, you have to fully warm the engine drivetrain put the car level on a lift "CAR LEVEL",
WITH THE ENGINE RUNNING remove the fill plug on the drivers side of the trans. You add fluid till it runs out of the fill hole. Reinstall the plug "WHILE THE ENGINE IS RUNNING!!!".
IF,,,,,,, SOMEONE REMOVES the plug without the engine running, the trans will puke out a LOT of the required fluid fill and it will be low enough to damage the trans if operated for a long period of time.
I guess if you lifted the car at a steep angle from the drivers side, you COULD force in more than it needs but, that's about it.
BC
To correctly fill it, you have to fully warm the engine drivetrain put the car level on a lift "CAR LEVEL",
WITH THE ENGINE RUNNING remove the fill plug on the drivers side of the trans. You add fluid till it runs out of the fill hole. Reinstall the plug "WHILE THE ENGINE IS RUNNING!!!".
IF,,,,,,, SOMEONE REMOVES the plug without the engine running, the trans will puke out a LOT of the required fluid fill and it will be low enough to damage the trans if operated for a long period of time.
I guess if you lifted the car at a steep angle from the drivers side, you COULD force in more than it needs but, that's about it.
BC
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
YEP! LOL!
If it were ME, I would clean the entire bottom of the car/drivetrain. Take the car for a drive and then reinspect and see if there are any leaks.
There is a portion of the torque tube bell housing to differential housing where the fluid can leak out. Take a special look in that area, If it leaks ATF there, the trans output rear seal is leaking
Bill
If it were ME, I would clean the entire bottom of the car/drivetrain. Take the car for a drive and then reinspect and see if there are any leaks.
There is a portion of the torque tube bell housing to differential housing where the fluid can leak out. Take a special look in that area, If it leaks ATF there, the trans output rear seal is leaking
Bill
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Melting Slicks
Joined: Jan 2009
Posts: 3,275
Likes: 739
From: Miami FL
Make sure they are aware of the correct fill procedure. Some transmission shops have never worked on a C5, or might not be familiar with the correct procedure.
Thread Starter
Racer
Joined: Mar 2019
Posts: 302
Likes: 51
From: Northern NV
Melting Slicks
Joined: Jul 2006
Posts: 2,332
Likes: 31
From: Silver Spring MD
You can overfill the trans but you probably have a leaky line
You should fill the AT when it is hot and not cold. Instructions elsewhere on the forum. I had a leaky line going from the trans to the cooler in the radiator, If ATF is not leaking at the trans it could be leaking from one or both of the lines to the radiator.
Thread Starter
Racer
Joined: Mar 2019
Posts: 302
Likes: 51
From: Northern NV
Other than not having it level when you out the ATF in it, how do you overfill it?
Instructor
Joined: Jul 2018
Posts: 226
Likes: 39
From: Fall Branch, TN
Based on the directions above, doing that procedure with the trans cold would result in it being over filled.
I’ve never dealt with one of these. But I’ve filled countless transmissions through a dipstick tube. Same concept as far as temperature.
I’ve never dealt with one of these. But I’ve filled countless transmissions through a dipstick tube. Same concept as far as temperature.
