Hi all!
This is my first post and you all seem pretty detail oriented, so I'll go into as much detail as I can.

I need to refill my automatic transmission.

I have a 2000 Dakota Quad Cab with a 3.9 V6 and 2 wheel drive. It has 187,000 miles on it. I don't know the specific transmission it has and I can't go look because its parked at my aunts house about 30 miles away.

My drive shaft broke and pulled out of the back of the transmission and all the fluid drained out while it was being towed. The drive shaft broke because the exhaust system came off a hanger and a clamp rubbed against the shaft as it turned and eventually cut through it about 15 inches forward of the differential.

Years ago, a mechanic told me that I should NEVER change the fluid in that transmission because the new fluid would eat away something in there (The bands or plates or something) and I would have to replace the transmission. The fluid that drained out was still BRIGHT red and had no burnt smell to it, as it has always been. To my knowledge, the fluid has never been changed (I never did it and I have owned it since 2005)

I am now afraid to put new fluid in there because I DO NOT want to have to replace that transmission (It has worked perfectly for the entire time I have had it, Including moving across the country twice towing a 7,000 lb trailer).

I would want to put Royal Purple Max ATF in it (This would be the last fluid in the entire truck that is NOT Royal Purple).

Basically my questions are:
(1) Will putting new fluid in the transmission ruin it?
(2) How much should I use?
(3) Should I replace the filter? (I heard that there are actually 2 filters in there, should I replace both of them?)
(4) How do I go about doing it? My shop manual is less than helpful about this topic.
(5) is there anything else I should be watchful for or careful about?

I have a couple of days because I'm probably going to have to have a new drive shaft custom made (No junk yards have one near me and not even the stealership can find a replacement in inventory).

Thank You all in advance!!!
-Daniel

 

1. Whoever told you that if you change the fluid in a transmission will ruin it is not a mechanic. CHANGING THE FLUID WILL NOT RUIN A TRANSMISSION IN ANY WAY. That's like saying changing the oil in you engine will ruin it. All fluids in a vehicle should be changed at some point.

2. The Service manual says that when the fluid and filter is changed the amount of fluid required to refill it is approximately 4 quarts. Also whatever brand of transmission fluid you use make sure its ATF+4 .

3. If you change the fluid you should change the filter to. After 187,000 miles I'm sure it could use it.

4. When releasing the bolts on the transmission pan, take them out so that you can release just one corner so the fluid can drain out that corner as there is no drain plug like an oil pan on an engine. If you try to drop the whole thing at once you will make a huge mess. It may be stuck on there so use a screwdriver or something similar to pry the corner loose. When the pan is removed there will be 2 or 3 bolts holding the filter to the valve body in the transmission

5. Be sure to clean the gasket surface on the pan and where it mounts to the transmission or else it could leak and use a new gasket. The filter bolts torque at 35 in. lbs and the pan bolt torque at 150 ft. lbs if you want to get it exact. It would also be a good idea to replace the rear seal where your drive shaft goes in to prevent leaks.
Thats pretty much it. I hope this helps you. If you have anymore questions just ask. Everyone on here is very helpful.