Transmission fluid change advice needed!

[Cole94]

So I did the pan drop with the filter about 5k ago, and the fluid was dark, thin, and I don't know what burnt tranny fluid smells like but it reeked. There was hardly any metal shavings, but there was a bit of black sludge.The transmission fluid was last changed before 200k probably and we are at 260k.

I have heard the horror stories about flushes, but would the method described here where you have the transmission pump out the old fluid and you add new fluid to the filler tube damage the transmission? It shifts fine, at about 2500-3000 rpm and smoothly, but there is a half second delay when putting it into drive or reverse.

Going on a long trip and I need the x in good condition. Thank you in advance for any input.

 

[gmanpaint]

Half fluid/filter changes with "about" 6 months/12k between (avg mileage) is the best way. New fluids have fresh detergents that can break free lodged crud. A little at a time is best so it gets to the filter, and not block a passage. If your real concerned, and you have some good miles put on it since the last change, then do another pan drop, filter change, and fill it back up.

There might be some blockage already in the valve body if it's hesitating into gear like you said, or it could be something else like a solenoid. Check your vac line to the modulator to make sure it's on good, as that can also cause a hesitation into gear.

The black sludge concerns me tho. That might be clutch materials that have burned up. Once those are slick, it's time for a rebuild. Heat and bad/low fluids will cause that to happen.

 

[Roadrunner777]

I'll tell you what I did... it was pretty easy and there were no problems. I ran a tube down the dipstick pipe, sucked out all the fluid I could, and then filled it with new fluid. Then I drove it for a few weeks and repeated the process. I think I ended up doing that 6 times and I calculated that would get me back to about 90% of new fluid. The fluid l sucked out looked better each time. The original fluid was almost clear with tiny black specs.

Oh, do not trust the car parts place to recommend the fluid. Use Mercon V.

 

[BrooklynBay]

Adding an external filter is recommended.

 

[VA7LFD]

Are there any diagrams on where to add an external filter?

 

[gmanpaint]

Inline filters can be placed near the front, close to the cooler, using the coolers rubber line.

 

[BrooklynBay]

Place the filter on the cooler's return line.

 

[Maniak]

Are there any diagrams on where to add an external filter?

I found an old picture of the external filter on our Explorer.

Trans filter, top view by maniak_az, on Flickr

The pressure on the in and out side of the transmission cooler (heat exchanger) in the radiator is close enough that IMHO it doesn't matter which side you plumb into. That is just a remote oil filter mount for an FL1A type filter (same kind used on the 1st gen explorer engine) with rubber transmission hose. I've seen remote filter mounts with 90 degree fittings and other are vertical like what you see in my pic.

I change that filter every oil change which also changes out 1 quart of trans fluid too.

~Mark