NAG1 transmission fluid change

[Bailey28]

2013 Dodge Charger R/T 75,000 miles on it. PO never changed the transmission fluid and I was having a mild shudder issue in higher gears.

I used a Vevor 6.5L fluid pump to pump out the transmission pan prior to removing it. The Vevor worked well, great suction and the fluid came out with no problem. The Vevor came with long nylon hoses however no measurement scale listed in Quarts/ounces. You get half liter graduations only. I made a scale and marked the side of the cannister to help my brain process liters to quarts.

After I drained just over 3 quarts out I removed the pan and filter. I had to support the rear of the transmission with a jack then remove a crossmember to access the rear two pan screws. Out came the pan and filter, about another 3/4 of a quart of fluid too.

All went back together well, no issues. Torqued the pan to 71 in/lbs, filled the transmission with 120oz. of new ATF+4 fluid. The shudder was almost gone. I have since changed out another 3 quarts, then another 3 quarts again via the Vevor pump from above over the past week so I think 'most' of the fluid has been changed at this point.

Napa has ATF+4 for $6.99 a quart right now, says 'engineered by Valvoline' on the bottle.

 

[demarpaint]

It sounds like a job well done.

 

[meep]

NAG1 / WA580 IMO is one of the best transmissions of all time. Certainly one of the best I’ve owned. You didn’t catch the fluid change too late, but it is old enough to expect to feel a difference.

 

[Bailey28]

Sooooo... the torque converter shudder is still there in the higher gears, 3, 4, and 5. Got a P0741 code for the torque converter performance clutch circuit stuck off.

I need to remove the valve body and replace the conductor plate and the TCC solenoid. This is the fix most online sources are saying will fix the shudder.

Edit: A few weeks ago I added one 2oz. tube of Lubegard shudder fix. I did instantly feel the shudder reduce by about half.

I'll admit it is easy to add a tube of mechanic in a bottle and be done for a while but I would rather address the problem itself.

 

[meep]

If you’ve done your homework and theres good info out there, bottom side work probably isn’t that bad if you get everything set up, go workspace and all that. NAG1 is worth the effort.

 

[Bailey28]

Update: I pulled the valve body and replaced the conductor plate as well as the TCC solenoid. I used the Dorman part 917-678 which looked the same as the original part coming out. The plate came with the wiring harness connector and O rings. No O rings were included for the solenoids. I bought a supposedly 'oem' Mercedes TCC solenoid, It had the Mercedes logo and part number stamped and engraved on the body of the solenoid same as the old one.

The valve body was heavier than expected. After changing over the solenoids and cleaning two mesh screens I reassembled everything. No leaks, and the car drives much better. Torque converter lock up is smoother and with no to minimal vibration.

The only time I feel a very slight vibration is in 4th and 5th gear when slightly accelerating when the ECO light is on. I am thinking this is the HEMI MDS cylinder deactivation I am feeling. It feels like a slight buzz coming from the rear of the car.

 

[Bailey28]

Still some minor shudder... Drained and filled another 3.5 quarts from the pan. Refilled with Valvoline ATF+4 to the proper level.

I have read these transmissions are very sensitive to moisture content in the fluid. I did not see obvious signs of water contamination upon collecting the old fluid although it makes sense that each time I change out a little fluid the shudder is reduced by a small amount.

I believe the car has the transmission cooler integrated into the condenser, thus no engine coolant could get into the fluid.

If there is water contamination in the fluid from the car sitting for a few years perhaps a few more drain and refills will solve the shudder issue totally.

 

[Bailey28]

At this point, would I be better off sending of a sample of the fluid to get an analysis of what the concentration of water is in it, if any? ATF+4 is expensive to keep changing out. Anyone know if there are DIY kits to test for water content?

 

[meep]

you’ve eliminated so many variables that point away from oil and controls. There’s a chance maybe that the clutch material could be somewhat abused by the P.O. Since you’ve replaced the fluid, consider another small or partial dose of lubegaurd and just drive it for a while?

Are there adaptive for this transmission? Can they be reset?

 

[Bailey28]

It has stopped throwing the P0741 code after replacing the TCC solenoid and conductor plate. It really shifts well both up and down, no complaints on going into gear, no noise, runs at 163*F max. Aside from mild shudder at light throttle the transmission is just smooth.

I really would like to reset the TCM or find a way to do that without bringing it to a dealer.