My corvette is a 2004 automatic with 83k miles. I plan on doing a trans service soon but I’m a little stuck. The dealer recommends a full service with a flush, and another small shop I called recommends just a drain+fill and filter change. The car is about 20 years old and I couldn’t find a record for a previous trans service so I’m assuming this would be the first time it’s serviced. What do you guys think is the safest route to take?

 

Just drop the pan and change the filter and refill with Amsoil Signature ATF (my personal recommendation) - your best bet on an automatic.

 

Yup, I agree. I changed my fluid and filter @100,000 miles. I used regular old Dexron III. I'm now at 137,000 miles, trans is still all original. OP should do as you say, and what I did....

 

Agree with the above. Drain trans, replace the filter and refill. Have done this on mine a couple of times, have 208k+ miles on the original trans.

Gary

 

No flush. Your new filter will more than compensate for anything left that a flush would provide.

 

In my 65 years of driving I have never had a transmission flush and never had any issues.. The flush is just a way for the dealer to con you out of more money!

 

No flush required. Just drain, change filter, refill following fill instructions. I would recommend a small fluid vacuum for removing most of the fluid prior to the pan drop to avoid the mess. Also, if it's still the original gasket on the pan, it may need some heat to get the material off the pan. Mine did.

 

Moved to C5 Tech for additional comments.

 

Changing the fluid and filter on a C5 A4 is fairly easy, but there are specific procedures to insure that the fluid level is correct after the change:

After replacing the filter and bolting the pan back up, fill with new fluid to the drain/ check level plug hole. Then start the engine and leave it running with the transmission in PARK.

Immediately add fluid through the drain/ check level plug hole until fluid flows out of the plug hole. It may take as much as another couple of quarts.

With your foot holding the brakes, cycle the transmission through all the gears, then back to PARK.

Go back underneath and make sure that fluid is still dribbling out of the fill/ check level plug hole. You might have to add some.

With the engine still running and the transmission in PARK, monitor transmission temperature on the DIC. When transmission temperature rises to 122 F, put the plug in the fill/ Check level hole. Keep a pan under the hole, fluid will dribble out as the transmission temperature rises.

Do NOT shut the engine down until the plug is in the fill/ check level hole. If you do, HOT fluid will gush out and the transmission will be low on fluid.

I recommend full synthetic fluid.*

Keep in mind that the above procedure drains about half the fluid in the A4. The other half is in the torque converter and other works.

You will need a small hand pump to pump the fluid into the fill/ check level hole.

*My car is at 119.000 miles, 26 road course track days so far. I have changed the fluid and filter five times, always with Red Line D4 full synthetic.