[cvc 22349a]

I'm due for an AT fluid replacement, first time at 50k was drain and fill approx. 5 quarts. My question is can the torque converter be drained as well or does it have to be flushed. Is it advisable to flush the transmission or just drain and fill? I'm at 100k.

[kkasson]

Drain and fill should be fine.

If you want to be thorough you can drain and fill it once or twice without dropping the pan and then shortly after drop the pan and replace the filter. I try to do it that way but sometimes due to time constraints I just do it once. There's not a whole lot of fluid left in the torque converter, and in my experience the fluid is actually still in relatively good shape at 100k and the little bit left over will be fine.

[BashShah]

Originally Posted by kkasson

Drain and fill should be fine.

If you want to be thorough you can drain and fill it once or twice without dropping the pan and then shortly after drop the pan and replace the filter. I try to do it that way but sometimes due to time constraints I just do it once. There's not a whole lot of fluid left in the torque converter, and in my experience the fluid is actually still in relatively good shape at 100k and the little bit left over will be fine.

1+

[robthewrench]

If you are at 100K and did one service already, a drain, filter change, and fill should be fine. I would not do a flush unless you are trying to fix some issue. As others have mentioned, if you want to get more of the fluid changed, you can just drain and fill twice.

[labrador]

These torque converters cannot be drained like Mercedes. Drain and refill is good. I would do the filter too.

Are you doing your own work? Just follow the DIY.

[mweisdorfer]

Originally Posted by labrador

These torque converters cannot be drained like Mercedes. Drain and refill is good. I would do the filter too.

Are you doing your own work? Just follow the DIY.

Not true.

You can flush the torque converter via disconnecting the return line to the trans cooler. Turn on the car and let it fill a gallon jug about 3qts at a time. You do have to fill the the pan with 3 qts before you turn the motor back on.

You'll need 12-14qts of ATF in order to do this job correctly, but it can be done. I have done it.

The only specialty tool you'll need is the "key" type tool used to compress the hydraulic fitting on the trans cooler, in order to take the line off of the cooler.

You can get one on Amazon for around $14.00

[labrador]

I guess there are two parts of OP's question.

No, the torque converter cannot be drained like a Mercedes where you remove a drain plug.

Yes, you have to do the cooler line flush. However I would advise against this because the thermostat in the cooler might be open (or if closed it might drain out), leaving you under filled. It is still possible, but you will have to warm up the transmission to over 75C and then allow it to cool back down to refill the circuit.

I would recommend three drains and refills over a few days or weeks.

[cvc 22349a]

Ended up just doing a drain and fill with a new pan and glad I did. The 5 quarts that came out were black. Shifts much smoother again. Hoping to get at least 150k out of this trans.

[Big Mexican Women]

Originally Posted by cvc 22349a

Ended up just doing a drain and fill with a new pan and glad I did. The 5 quarts that came out were black. Shifts much smoother again. Hoping to get at least 150k out of this trans.

good stuff. I would recommend also changing the valve body and shift solenoids.

[labrador]

Good to hear. You can do another drain/refill to get rid of more of that old fluid. However, I'd change the filter too.

What fluid did you use?

Originally Posted by cvc 22349a

Ended up just doing a drain and fill with a new pan and glad I did. The 5 quarts that came out were black. Shifts much smoother again. Hoping to get at least 150k out of this trans.

[cvc 22349a]

Originally Posted by Big Mexican Women

good stuff. I would recommend also changing the valve body and shift solenoids.

Now you tell me I'll try to remember that. I think the valve body is what goes first? Wonder what that costs.

[cvc 22349a]

Originally Posted by labrador

Good to hear. You can do another drain/refill to get rid of more of that old fluid. However, I'd change the filter too.

What fluid did you use?

Lifeguard 6, same as the first time.

[cvc 22349a]

Originally Posted by labrador

I guess there are two parts of OP's question.

No, the torque converter cannot be drained like a Mercedes where you remove a drain plug.

Yes, you have to do the cooler line flush. However I would advise against this because the thermostat in the cooler might be open (or if closed it might drain out), leaving you under filled. It is still possible, but you will have to warm up the transmission to over 75C and then allow it to cool back down to refill the circuit.

I would recommend three drains and refills over a few days or weeks.

That's a lot of $$ for a 100k trans. I don't diy.

[Big Mexican Women]

Originally Posted by cvc 22349a

That's a lot of $$ for a 100k trans. I don't diy.

unless your're very overdue on your fluid change you don't need to worry about the torque converter fluid. what's most important is changing your solenoids while you have the pan opened up, and preferably your valve body too.

[labrador]

Understood. A shop charges arm and leg.

ZF LG8 for me is about $23/L (our Audi), so about $140 in flud each time. Much more expensive than GM Dexron VI, takes $30 of fluid each drain/refill.

Originally Posted by cvc 22349a

That's a lot of $$ for a 100k trans. I don't diy.