Hello - I bought my first truck recently. It is a 1997 Ford Ranger, 2-wheel drive, 4-speed automatic transmission, with a 2.3L engine that has pushing 200K miles on it. I ran across this forum the other day when wondering around the web looking for part and what not for the truck. What brought me back is what a local transmission guy told me today that isn't making sense with what I've been told for years. I stated my transmission fluid was ugly (not a nice red color), was over full, and that I was going to replace the transmission filter and fluid. The tranny mechanic said "I wouldn't do that if I were you". When I asked why he said the detergents in the new transmission fluids will break down the tarnish inside the transmission and that can cause all types of problems. I thought getting rid of varnish was a good thing? This is a first for me, as I've always been told if the tranny fluid isn't looking right get rid of it and put new fluid in it. So, I figured I'd come to a Ranger forum to ask what other owners of the same type vehicle has to say...

This is also my first post in a Ford Ranger forum

 

Welcome to the forum

You have a 4R44E transmission in your 1997 Ranger
You have a 2.3l SOHC Lima engine, 1997 was the last year for this engine.
It was first used in 1974 Ford Pinto, so had been around for 23 years, good reliable engine.
In late 2001 Rangers got the 2.3l DOHC Duratec engine, Mazda L engine, I mention this because a Google search using "Ranger 2.3l" will have BOTH engines showing up and they are not even close to the same, only thing they have in common is they both run on gasoline, lol.

As for the transmission................varnish(tarnish?), really?
I am still hesitant to FLUSH engine oil and transmissions systems, for coolant I like it, but don't see the good of it for oil and ATF.

Change the fluid and filter.
If old fluid is burned, darker color, then transmission is slipping most likely.
So keep an eye on fluid color after changing it.

Heat is what kills ALL automatics, since the first one was made, nothing new.
Automatics have multiple clutches and Bands(brakes), these are what control the position of the planetary gears, which sets the ratio.
Fluid pressure is what holds clutches open and engaged, and what holds brakes(bands) on or off.

The Valve body of the transmission routes this pressure, around 1985(when fuel injection computers were added) solenoids were installed in automatics to route the pressure, these were more reliable and had better shift control than the old style "ball and spring" valves.
And there was a computer on board now to operate these solenoids.

But............the age old problem with automatics still comes up, leaks in valve body gaskets and valves
This lowers pressure so clutches can't hold as well and neither can the brakes, and this SLIPPING causes HEAT!!!
ATF doesn't like heat, it gets thin and burned, and you have even less pressure.

Reverse requires the highest pressure to engaged, 175+psi, slow to engage or no reverse is a pressure issue.

This is why 2nd trans coolers, in my opinion, is not an option, it is a must for any automatic, best $60 you will ever spend on a car or truck with an automatic.

4R44E valve body can be changed without pulling out the transmission, and there is a newer model valve body with bonded gasket.
Not that you are there yet, just saying.

Generally speaking 300k would be full rebuild time, the clutches and brakes(bands) do wear out, just like brakes on vehicle, or clutches on manual trans.

 

That is a lot of good information and I appreciate you taking the time to provide it. I've copied it to a text file in my Ford Ranger (1997) folder. Today I sucked out as much brake fluid as I could from the reservoir and topped it off and will rinse/repeat a couple time after use - but, it all needs to be bleed out and replaced. I also sucked out some of the tranny fluid thru the fill tube (over a court - it was over full when I got it) and topped it off with a quart of new fluid. I got a new tranny filter/gasket last night, but I'm wanting to get a new pan with a drain plug to put on it.

I'm going to have to look into the second transmission cooler. Living here in Florida we get some hot days time to time.

Thanks again for the great info...

 

The old "dont change your fluid" argument is based on the theory that the old burnt up fluid contains clutch material that is keeping the transmission from slipping. Also that the gummed up fluid is preventing leaks. Neither of these are valid arguments to not change your fluid. If your transmission is so far gone that changing the fluid causes issues, it was going to die soon anyway.

Remeber dropping the pan and changing the filter only changes about 40% of the fluid. Most of the fluid is held in the torque converter which will not get replaced. You may want to consider adding a drain plug to the pan while you have it off, this way you can easily change out a few quarts every couple hundred miles until all the fluid is "fresh".

 

I want to buy one of those transmission pans with the drain plugs on them, so I can drain the fluid a couple times (like honda says to do). However, I came across the Dorman Steel Drain Plug kits for like 6 bucks. I might try that, as I have to drop the pan anyways and I have all the tools, etc. BUT, I was wondering if anyone has tried the drain plug kits and if they are worth it or if they leak, come loose, etc.

 

I've always welded mine on but if you don't have access to a welder the plug kits made by B&M are good quality and only about 10 bucks. I would avoid the no-name brand kits.