This transmission was used in all Auto trans equipped Front Wheel drive Chrysler products beginning in the late 70's until 1989, when the New A 604 Ultradrive electronic 4 speed transmission was introduced, and the 3 speed was used less and less. The 3 speed is still used today in the Neon. The transmission has been called by several different names, but they are all basically the same transmission with minor changes to the case to accept different engines as follows:

• A-404 - used with the 1.7 liter engine.
• A-413 - used with the 2.2 and 2.5 liter engine. Available with or without lockup converters.
• A-415 - used with the 1.6 liter engine
• A-470 - used with the 2.6 liter MMC engine
• A-670 - used with the 3.0 liter V-6 MMC engine, came with the lock up converter.

It appears that the V-6 and turbo transmissions have 4 clutch disc packs, Where the others only have 3 or less. (note: Ihave found the above to be only a guide line! I have found the 4 clutch pack in NA trans, and 3 clutch disc in Turbo Mini van transmissions, so, as usual, nothing is a hard and fast rule.

Quick rebuild

I have went through a few steps for "freshening up" a transmission. I would strongly recommend buying the transmission rebuild manual from:

Automatic Transmission Service Group (ATSG) 9200 S. Dadeland Blvd. Suite 720, Miami, FL 33156 (305) 670-4161 or 1-800-245-7722

This book appears to be a exact copy of the transmission section of the Factory service Manual. I think the factory manual actually includes more info than the ATSG manual, but it is also much more expense than the $12.99 The ATSG book cost! Do not buy the Chiltons book on transmission repair for all domestic cars from 84 to 89. It is over 800 pages and includes step by step instructions on all transmissions except the 3 speed chrysler. It does have a large section on the 4 speed electronic 4 speed.

Required tools:

• Chrysler uses 4 main bolt head sizes, 10 mm, 13 mm, 15 mm, 18 mm. You must have these sizes in both deep and shallow sockets and wrenches.
• You will also need a 8 mm socket for work on the transmission.
• A 32 mm socket to pull the axles.
• 2 Jack stands and a floor jack. Also either another jack, blocking, or one of those "over the engine" bars to support the engine while the trans is out.
• Regular and Phillips Screw drivers
• A set of TORX bits. I use a "Eklind" fold out set, like the hex key sets.
• Pliers, Channel Locks, Vise Grips, hammer etc.
• Electric drill and small (3" or 4" in dia) wire brush wheel for it (to clean off gaskets)
• Feeler Gauge set

Supplies:

• Several cans of Carburetor Cleaner for cleaning off parts
• 8 quarts of 7176 (ATF+3) Transmission fluid. ATF+4 fluis is also backwards compatible with the ATF+3 fluid, and can be used.
• Rebuild kit (got mine from the dealer $85 - Mopar PART NUMBER 04798215AD)
• RTV Gasket sealer

Optional parts for racing:

• 4348679 pinion gear (spider, 2 reqd) $22.50 ea
• 4659502 gear diff (axle side gear, 2 reqd) $36.70 ea
• 4659142 Shaft pin (spider gear shaft 1 reqd) $10.70 ea
• 4412521, spider gear washer (2 reqd) $1.60 each
• 4504568 washer shim kit for diff (2 reqd) $9.90 ea
• 4800059-AA Bracket, pin retainer. (2 reqd) $4.20 ea
• 4539123 or 4539124 snap ring for clutch pack, $3.00 ea

Rebuild procedures

1. Take the car to a spray car wash and really clean the transmission well. It should be almost sterile when you open it.
2. Break loose lug nuts and disconnect the battery.
3. Jack the vehicle up and place it on jack stands, preferably behind the K frame to prevent them from interfering.
4. Remove the wheels & disconnect the battery.
5. Both axles will have to be removed.
6. Drain the transmission fluid by removing the pan (10mm). Once the fluid is drained the pan should be reinstalled to avoid damage to the internal components while pulling the transmission. If the fluid is not drained it will spill out of the axle holes at the worst times.
7. Remove the 4 torque converter bolts 18 mm. You must remove the dust shield from the bell housing to gain access.
   • The flywheel bolts to the torque converter only one way. One bolt hole is off center. It is the slotted bolt hole in the fly wheel. In order to easily realign the converter to the flywheel when you put the trans back in, you should mark the two before you unbolt them. As soon as I pulled the dust cover, I sprayed some spray paint up in there on the flywheel and converter to mark them. The converter will have a circle stamped next to the odd bolt.
8. You must support the engine before you disconnect the transmission. I just put a jack under the oil pan with a board on it to keep from denting the oil pan, or build a cross bar support system.
9. Remove 2 bolts on the back of the trans below the starter (18 mm).
10. Remove the speed sensor (10 mm).
11. Remove the one 15 mm starter bolt (behind the engine, above the axle).
12. Pull the starter back out of the way. (if you havent disconnected the battery, now would be a good time).
13. Remover the 2 bolts on the front motor mount, to the trans bell housing (15 mm and 18 mm).
14. Disconnect the cooler hoses and electrical plug.
15. Remove the shifter cable and kick down cable (13 mm), it should just pop out of the arm.
16. Attach a cherry picker to the top bolt hole in the trans close to the timing window.
    • I have lowered the trans with a floor jack with a board between the jack and trans pan, but I prefer to use a engine lift crane (Cherry Picker) and lift the trans from the top and lower it down to the floor from above. Easier to lift back up into the car with picker too. By attaching the chain form the cherry picker to the bolt hole close to the timing window the transmission is at the right angle to mate to the engine.
17. Remove the 3 short bolts and one very long bolt from the drivers side motor mount (15 mm).
    • The front motor mount can be left attached to engine block (two bolts) but I had to loosen them for realignment when I put the trans back in.
18. Remove the last two bolts on the top of the bell housing (18 mm).
19. Its loose! Don't drop it!

From personal experience this procedure takes about 2 hours in a garage with normal tools. Installation is performed in reverse order. It is important to note that before the transmission should be lifted back in, the "odd" hole should be straight down and should be marked. Then the torque converter should be turned so that the "odd" hole is also straight down. If this is not done then a lot of time will be wasted trying to match up the right hole.

How it works (simplified)

The basic driving parts of the transmission that control which gear you are in consist of two "clutch packs", and two "bands" These act upon a planetary gear set which give you three forward and one reverse gear by stopping (or turning) the different gears in the planetary set. Which gear is which speed is not that important. The clutches are in "drums", and the band wrap around and squeeze the drums. If the clutch is compressed, power will travel straight through the assembly. If the band is tightened, the drum cannot turn. The drums are attached to the ring gear, and the front clutch pack is attached to the rear clutch pack. Difficult to explain, but the point is, through different combinations of clutch and band engagement, the gears are shifted.

In drive:

1. In 'first" gear, The rear clutch is engaged, everything else is loose.
2. In "second" gear, The rear clutch stays engaged, but at the shift to second, the front band tightens on the front clutch drum. While in second gear, the rear clutch and front band are tight. At the shift to third, the front band loosens, and the front clutch tightens.
3. In third gear, both clutches are tight, both bands are loose.

In reverse: The rear band tightens, along with the front clutch.

The only time the rear is "engaged" is when the shifter is moved to D. It remains engaged in all forward gears. If yours is slipping in all forward gears this could be the problem. I would guess this is the "neutral drop damage clutch". A loose 1-2 shift could be a loose front band (adjusted outside the case). A loose 2-3 shift could be worn front clutch disc. The 2-3 engine flare up is caused when the front band lets go faster than the front clutch engages. The clutches are not 'self adjusting", so the more they wear, the longer the stroke to tighten them. The longer the stroke, the longer it takes to shift.

Any problem can be caused by dirty fluid or a filter. I will not discuss change intervals, but before you decide on a rebuild, pull the pan, look around, and put in a new filter and fluid. You may be surprised at the improvements!

Dis-assembly

Note: the following is a guide to replacing the clutches and setting them up. This is a normal rebuild. If your transmission was like mine, it shifted gears at the proper time, and in the right order, I had just burned up my clutches and it was slipping in gear. Every thing else should just be cleaned and inspected for damage, and replacing the seals and gaskets.

1. If the transmission is not clean, clean it. If you pulled the pan to drain the fluid, and it was full of metal parts or shavings, I would consider getting a new transmission. You may discover the cause of the metal, but it will be difficult to clean completely, especially the converter. This will cause shifting problems with the valve body and governor.
2. First, temporarily tighten the front band adjustment bolt. this will hold everything inside the case while you pull the front pump. The picture shows it very loose. you must tighten it pretty snug.

   

3. Pull the pump out the bell housing. I used two 3/8 bolts about 6 inches long, and pulled them out with a hammer. Two of the bolt holes a threaded so the 3/8 bolts thread into them. They are actually metric 10 mm bolts, but regular 3/8" bolts will work, just a little loose. I have went through so many transmission I "label" what they came out of and the date I put it in.

   

   The pump actually comes out pretty easy. You can almost pull it out just by grabbing the 3/8" bolts, but I used a claw hammer for a little leverage.

   

4. After the pump is out, loosen then front band bolt again so you can get out the clutch drums and the front band. When you loosen the adjustment bolt, the small "H" bar will fall out, probably into the pan.

   

   Here are the parts as they came out:

   

5. My kit did not come with replacement bands, and mine looked ok to me. I don't think they wear out too often. I just left my rear band installed. This as far as I took down the clutch and gear section of the transmission. My gears worked ok, it just slipped in gear.

   

6. The front and rear clutch drums slide off each other, and the input shaft. To replace the clutch plates, just remove the snap ring.

   

   They come out in alternating between the clutch disc and the steel. Pay attention to the order they come out in.

   

7. This is how you check the clearance. Mine was LOOSE! I could stick a 16 penny nail in the gap! The "H" bar is next to the clutch drum. You should check the clutch clearances before and after installing the new plates.

   

   The performance snap rings #4539124 are about .110 thick and # 4539123 are about .097 thick. You want about 40 to 50 thou clearance. Set the rear clutch at the low limit on the spec too. I always seem to use the .110 thick ring. Do not reuse the "wave" washer you took out.

Differential

Parts needed to rebuild a diff:

• 4348679 Pinion gear (spider, 2 reqd) $22.50 ea.
• 4659502 Gear diff (axle side gear, 2 reqd) $36.70 ea.
• 4659142 Shaft pin (spider gear shaft 1 reqd) $10.70 ea.
• 4412521 Spider gear washer (2 reqd) $1.60 each.
• 4504568 Washer shim kit for diff (2 reqd) $9.90 ea.
• 4800059-AA Bracket, pin retainer. (2 reqd) $4.20 ea.

To remove the differential, remove the stamped steel cover (10 mm socket) then the 4 long bolts on the pass side bearing support, and the 6 shorter bolts from the drivers side (image shows still installed).

All three of these items are installed with only silicone. Use normal practice to remove the cover. It will spill fluid. To remove the axle bearing supports, the supports must be twisted back and forth to work them out. To move the Speedometer side (shown loose above) I stuck a wooden hammer handle into the speedometer gear hole and used it to lever the support back and forth, breaking the silicone seal. On the drivers side, I put two of the bolts back in the holes, but made sure they did not go in far enough to keep the support from turning when I used a small pry bar to apply a twist to the housing. In the picture, I am pressing down on the bar, twisting the support. The diff. will fall out when both are loose.

Note. It is not required that you remove the differential but you MUST remove the steel cover and inspect the unit for damage. The spider gear shaft will sometimes fall out.

This one is about to damage the case! It looked like this when I pulled the cover!

The above picture to the right was taken from a friend who really liked to spin the tires. The pin came out here, can you imagine what happened inside! I have seen fluid leaking out of the bell housing where the pin came through case on the converter side!

Finally Chrysler has come up with a "Fix" for this problem, a bracket to keep the pin in: Part number is 04800059AA, cost about $3.00 each (You need two).

• Pin retainer brackets: 04800059AA
• Spider gears: 04348679AB
• Spider gear shaft: 04659142
• Shim washer kit 04504568

With these simple brackets, I leave out the little "tapped in" retainer pin completely, this allows the shaft to rotate in the case some, basically allowing the spider gears to wear on the shaft all the way around rather than in one spot (kind of like valve rotators). With the shaft rigidly mounted to the case, it always sees the force in exactly the same spot, causing wear in one spot, and it will bend. Also, the shaft is chrome plated, and once the chrome is worn through the shaft is going to chew itself up. With the abilty to rotate in the case, the gears bear on a differnt side of the shaft every time you punch it, I feel this greatly extends the life of the chrome plate and the shaft. This shaft is one year old:

You can see that it had sheared the little retainer pin anyway. This pin had a "spiral grove" cut in it to promote lubrication of the gears. It did not help.

A picture of the Future Auto Limited slip unit apart:

Valve body removal & adjustment

A "normal" valve body removal. Remove the shifter arms from the top, then the bolts marked. The yellow circles mark the bolts that hold the valve body into place. 10 mm socket. the two lower yellow circles on the left mark the park pawl retainer. I have found it easiest to remove the bolts, then swap the park rod over to the new valve body after it is out. (13 mm) The yellow arrow marks the governor pressure lines that will just pull out when you remove the valve body. The red circle marks the pressure adjustment screw. Loosen it (compress the spring) to raise the pressure! It is in the same place on the "factory" valve body also. I suggest raising the pressure a little on any transmission for a little firmer shifts.

To lower the shift points (sometimes required when line pressure gets too high), change the governor. Use the hollow "big" valve with the orange spring from a turbo trans and a solid "small" valve from a TBI trans. If you want still lower shift points, so you can up the line pressure. Lighten the big valve (hollow) a little by spinning it in a drill with the small end chucked in. Use a stone tipped die grinder and open the hole up on the big side a little.

The governor is located under (ok over) the valve body and is easy to get to. If anyone needs info on this trans get a service manual from Chrysler or for $14.99, order a ATSG Techtran manual from JC Whitney, part # 16zh7289u.

This article originally written by Paul E. Smith, was reproduced with permission from turbovan.net.