Changing automatic transmission filter and fluid.
Regular Vehicle Maintenance:

Changing Automatic Transmission Fluid And Filter In A 1993 Dodge Dakota

May Apply To Full-Size Dodge Trucks And Vans

 

In This Article:

After the vehicle is raised and placed on jack stands, the transmission pan is removed and the fluid allowed to drain. The filter is replaced. The pan is cleaned and installed with a new gasket, and new automatic transmission fluid is poured in the dipstick tube.

Related Articles:

Skill Level: 2-3 (Basic to Intermediate) Time Taken: About 2 Hours
Just Looking For Numbers? See Specification Summary near the bottom of this page.

By Bruce W. Maki, Editor

Start:

Everybody knows that it's important to regularly change the oil in their car, but many people are not aware of the other fluids that need to be changed periodically, such as coolant, differential fluid, and automatic transmission fluid.

Why does automatic transmission fluid (ATF) need to be changed? ATF is a very complex product designed to move the many hydraulic valves, apply numerous "wet clutches", and lubricate all the moving parts inside an automatic transmission. And the fluid itself actually transmits mechanical power in the torque converter, which is the device that lets the engine keep running when your car is stopped while in Drive or Reverse.

Read Fluid Change Interval at the end of this article.

Truck raised up on jack stands.

I jacked up the truck and placed it on jack stands.

When draining the transmission fluid, it's probably best if the vehicle is level, so I raised the rear and placed jack stands under the axle.

 

This is the automatic transmission pan, viewed from the rear.

Note the exhaust crossover pipe just in front of the pan... this pipe comes from the driver's side exhaust manifold. The engine is in front of this pipe... you can see the engine oil drain plug at the bottom of the picture, just below the exhaust pipe.

Automatic transmission pan, Dodge Dakota.

 

Front bolt locations, transmission pan on Dodge truck.

This picture is taken from the front, from just below the engine.

The exhaust pipe runs beneath the front of the transmission pan, but all of the bolts are accessible.

Note the brownish-looking bolt near the upper-right... that's the engine oil drain plug.

 

To catch the fluid, I placed a large plastic tub beneath the transmission pan.

At first I thought I might re-use the fluid, since my real reason for removing the pan was to see if I can fix the broken detent mechanism in the shift linkage.

The trans fluid still looked good: Nice cherry-red color, fresh "fruity" aroma (!). I last changed the fluid about 30 thousand miles ago.

Drain tub to catch fluid from transmission.

Normally I would just use a large oil drain pan to catch the fluid, letting the old tranny fluid mix with old engine oil.

Removing bolts on transmission pan, 1993 Dodge Dakota. I used a 1/2" socket and an extension to remove the bolts in the pan.

 

For some of the bolts near the exhaust pipe, I had to use a 1/2" box-end wrench, or the ratchet without an extension. Removing difficult bolts on tranny pan.

 

Draining transmission fluid, Dodge truck.

Red Rain:

I removed all but one of the bolts on the left (driver's) side of the pan, but I left two bolts in the right side to keep the pan from falling.

Then transmission fluid started dripping all over the place.

 

Fluid Quality:

Be on the lookout for dark, brownish transmission fluid. If the fluid is dark or smells burned, that's a sign of transmission overheating at some point in the past. Burnt ATF is often a death sentence for an automatic transmission.

Burnt fluid can be caused by "severe service", which includes things like towing a trailer or using the truck to plow snow. (More on this at the end of the article.)

Of course, every car owner should be checking their transmission dipstick once in a while, inspecting the fluid quality (color and smell) and the level.

 

When the fluid had slowed, I removed the other bolts and carefully lowered the pan while pouring the fluid into the catch basin. Chrysler automatic transmission with pan removed.

 

Transmission pan after removal, Dodge.

This is the automatic transmission pan after removal.

There was a black rubber gasket around the mating surface.

 

This is interesting... I found this little ball stuck to the magnet in the transmission pan.

Finding this little metal ball in the pan was like finding gold for me... about a year earlier the gear shift detent mechanism broke, which made it kinda tricky to drive the truck because it was easy to bump the gearshift out of gear.

I figured that this ball must be part of the detent mechanism.

Detent ball found in transmission pan.

 

Removing transmission filter, 93 Dodge Dakota.

Using a T-25 Torx bit, I removed the three screws holding the filter to the bottom of the transmission.

These screws are long... about 3 inches.

 

I removed the middle screw last, and when it was unthreaded, the filter came right off. Transmission filter being removed, Dodge truck.

 

The transmission without the filter.

All I need to do now is clean up the pan so it can be re-installed with a new gasket.

Dodge truck transmission without pan and filter.

If I was just doing a simple fluid change, I would install a new filter at this point, but I have more extensive repairs to make.

 

Cleaning The Transmission Pan:

Cleaning magnet in automatic transmission pan.

I removed the donut-shaped magnet from the pan and wiped off the sludge with a paper towel.

 

Using a small garden sprayer, I sprayed some mineral spirits (paint thinner) into the pan and brushed it with a parts cleaning brush. I drained the dirty solvent into my oil drain basin.

Then I sprayed some brake cleaner in the pan and wiped it clean with a paper towel, making sure there were no bits of paper towel left behind.

If the gasket area was even slightly dirty or rusted, I would buff the gasket surface on a wire wheel. A wire brush also works, but takes much longer. A clean mating surface is critical for the gasket to seal properly.

Cleaning transmission pan with solvent.

I put the magnet back in the pan so I wouldn't forget it when it's time to re-install the pan.

 

Adjusting The Rear Band Clutch:
(Optional)

There are two band clutches in the Chrysler 42RE and 46RE automatic transmissions. The front band (also called the kickdown band) holds the ring gear when the transmission is in second gear. The front band adjustment is outside the transmission case, just above and in front of the manual lever shaft.

The rear band, which is applied in first gear and reverse, is adjusted from inside the oil pan, so when changing the fluid it's a good opportunity to adjust this clutch.

Location of rear band clutch, Chrysler 42RE transmission.

The rear band is located at the back of the transmission pan, on the right-hand (passenger) side of the transmission.

Note that this picture was taken while lying on my back, so it's upside down from how you'd see it if the car was on a hoist... but this is the way you might see it if you were crawling under the vehicle.

 

The band is adjusted by loosening the locknut and turning the screw.

The nut requires a 9/16" or 14mm wrench, and the screw requires a 1/4" wrench or socket.

Rear band clutch adjustment screw and nut, Dodge truck.

 

Loosening locknut on rear band clutch, Dodge Dakota pickup. I used a 14mm wrench because it fit tighter. While holding the screw with a socket adapted to my long-handled 3/8 drive ratchet, I loosened the locknut and backed it off 5 or 6 turns.

 

Then I turned the screw until it got tight. Just for kicks, I counted the number of turns. At about 4 complete turns the screw began to get tight.

My Chrysler factory service manual says to tighten this screw to 72 inch-pounds, which is 6 foot-pounds. I don't have a torque wrench that goes that LOW, so I just estimated the torque.

Then, following the shop manual, I backed off the screw two full turns, and I tightened the locking nut (a lot more than 72 inch-pounds, I'll say).

Adjusting rear band clutch, Dodge Dakota pickup.

Estimating torque on something important like a band clutch sounds risky, but there are ways to be accurate. 6 foot-pounds of torque (rotational force) can be obtained by applying 6 pounds of force to a wrench where my hand is one foot from the center of the screw. Estimating 6 pounds of force becomes the next challenge. Consider that a gallon of water weighs about 8 pounds, so 6 pounds is as heavy as 3 quarts of water. Three quarts of oil would be a close approximation. I had some tranny fluid in a shopping bag, so I just lifted 3 quarts to get an idea of the weight. I tried to apply that force to the wrench.

I'm guessing that getting the torque exact isn't a big huge deal, because when that screw got tight, it got tight fast, and it turned about one-twelfth of a turn from snug to my estimate of 72 inch-pounds.

Considering that the screw went 4 turns inward and then 2 turns out, the net change is 2 turns in. In other words, the rear band clutch has worn a little, which is no surprise for a truck with 183,000 miles on the odometer. But the transmission shifted fine before I did this maintenance, so I guess that if I had to estimate the torque, I'd prefer to estimate too low, so the band would be just a bit looser than when perfectly adjusted. If the band is too tight it might cause problems such as a harsh upshift... I don't have enough expertise in automatic transmissions to predict exactly what would happen.

 

Re-Installing The Filter, Pan and Gasket:

Transmission filter and gasket kit, Dodge/Chrysler.

I bought this filter and gasket kit at my local NAPA auto parts store for about $14. There was a second gasket in the kit (top of photo)... sometimes these kits include multiple gaskets so all available transmissions on the vehicle are covered by one kit.

Here I've arranged the filter and gasket as they would fit on the vehicle, as viewed from above.

 

I installed the filter and tightened the screws. Be careful, these screws are threaded into aluminum, so it's easy to strip out the threads.

The service manual says to tighten these screws to 35 inch-pounds.

Installing filter screws, Dodge Dakota pickup.

 

New tranny pan gasket installed with pan bolts.

I cleaned the mating surfaces of the oil pan and the transmission case with brake cleaner. Then I laid the gasket on the pan and inserted the bolts through the gasket. (Earlier I cleaned the bolts with solvent to remove any dirt.)

The holes in the gasket are designed to be a bit too small, so the bolts will stay in place.

Then I installed the pan on the transmission, making sure that every bolt was started in its hole before tightening ANY bolts.

I tightened the bolts with a 1/2" socket and a 1/2" wrench. I needed the wrench at the front where the exhaust pipe blocks access. Actually, I found it easier to lay under the front of the truck and tighten the bolts, because I could use the wrench on the bolts that were in tight quarters, and it was easy to reach all the other bolts with a ratchet and extension.

As always, I tightened the bolts in a cross-pattern, starting at the center of one side and alternating to the center of the opposite side and working around the pan. I tightened the bolts gradually, snugging-up all the bolts in the cross-pattern, then doing them again, and again, before the final tightening.

The shop manual says to tighten the pan bolts to 150 inch-pounds, which is 12-1/2 foot-pounds. I didn't use a torque wrench... I don't have one that goes that low. Remember, these bolts thread into aluminum, go easy. It's a good idea to re-check the bolt tightness after the transmission has warmed up.

 

Refilling The Transmission With ATF:

Location Of Transmission Fill Tube (Red Arrow):

On my V6 Dodge Dakota, the trans fill tube is on the passenger side, near the back of the engine.

Location of transmission dipstick and fluid fill tube, Dakota.

 

Adding automatic transmission fluid, Dodge Dakota truck.

I placed a long-necked funnel in the filler tube and poured in new automatic transmission fluid.

Even though the Chrysler service manual says to use their own fluid (Mopar ATF Plus type 7176), I used Dexron III transmission fluid.

The manual says that Dexron II can be used to "top up" the transmission, but that when used for a fluid change Dexron II can cause clutch chattering.

This is the third time I've changed the fluid in this transmission, and I've always used Dexron II or Dexron III. I've never had a problem.

(Note that Dexron III supercedes Dexron II and can be used wherever Dexron II is specified.)

 

How Much Fluid:

I measured how much fluid I caught in my big plastic basin and it came to 6 quarts. I also spilled some fluid on the floor, and caught some fluid in a smaller dishpan when I removed the valve body (the reason I dropped the pan in the first place).

Normally I would start by adding 5 quarts and then running the engine for a few minutes, while shifting the transmission through all the gears. Then I check the level and add more as needed.

When checking the automatic transmission fluid level on Chrysler vehicles, the engine should be running and hot and the transmission should be in Neutral. Many other vehicles (such as GM) are to be checked with the transmission in Park, but every vehicle I've worked on needs to have the engine running to check the trans fluid level.

NOTE: Only Part Of The Fluid Actually Gets Changed: When the pan is dropped, only about half of the transmission fluid will drain out, the rest of the fluid is trapped inside. Some of the fluid is hiding in the hundreds of internal passageways, but the bulk of the trapped fluid is inside the torque converter. The total capacity of most automatic transmissions is often double (or more) of the volume of fluid that exits when the pan is removed.

 

Fluid Change Interval:

The Dodge Dakota factory service manual (the books used by dealer mechanics) has two service schedules:

Schedule A - Normal use. Chrysler recommends changing the automatic transmission fluid and filter every 37,500 miles.

Schedule B - Severe service, which includes vehicles that often tow heavy trailers or plow snow, and several other factors like frequent short trips, extended engine idling, driving at high speeds in hot weather, driving off-road, driving in dusty conditions, etc. Under these conditions Chrysler recommends changing the automatic transmission fluid and filter every 12,000 miles. Personally, I suspect that it's mostly the trailer towing or snow-plowing that truly subjects the transmission to "severe service".

 

I haven't been quite so disciplined with my vehicle maintenance... I changed the transmission fluid for the first time around 80,000 miles, and again around 150,000 miles. Now the truck has 183,000 miles and the transmission still works great. I wish the engine held up as well.

 

Disposing Of Used Transmission Fluid:

I normally let the transmission fluid drain into a large oil drain pan, allowing the old ATF to mix with old motor oil.

When the drain pan gets full, I pour my old oil-based fluids into gallon jugs and take them to a local garage that has a furnace that burns used motor oil.

Some auto parts stores, such as Advance Auto Parts, accept used automotive fluids such as motor oil and transmission fluid. Apparently they sell the stuff to companies that refine the fluid into usable products.

 

More Info:

Tools Used:

  • Ratchets, 3/8 Drive, 1/4 Drive
  • Extensions
  • Sockets: 1/2", 1/4"
  • Wrenches: 1/2", 14mm
  • Torx T-25 Bit
  • Oil Drain Pan
  • Dish Pan
  • Parts Cleaning Brush
  • Floor Jack
  • Jack Stands

Materials Used:

  • Transmission Filter and Gasket Kit, NAPA Part 1-7957
  • Automatic Transmission Fluid, Dexron III, About 6 Quarts.
  • Mineral Spirits (Paint Thinner)
  • Brake Parts Cleaner

Specification Summary -
Chrysler 42RE Fluid Change:

  • Fluid Type: Dexron II or III, (Mopar ATF Plus type 7176 preferred)
  • Fluid Amount: 5 to 6 Quarts
  • Pan Bolt Torque: 150 inch-pounds
  • Filter Screw Torque: 35 inch-pounds
  • Rear Band Clutch: Tighten screw to 72 inch-pounds, then back off 2 turns.

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© Copyright 2009 Maki Media Group LLC

Written April 20, 2009