Rebuilding a Chrysler A-413 Transmission

Here you will find how easy it is to rebuild the Chrysler A-413 Transmission.

For information regarding how to update the A604 transmission computer, see here.

This page will show you how to rebuild an A-413 transmission.  In particular all I am really showing is how to replace the "steels," the friction plates, and the both bands.  To start out it is probably wise to have the Factory Service Manual or the appropriate ATSG manual, which some sources say is just the transmission portion of the FSM copied into another book form.

Part number's listed on this page are pulled from the 1990 FSM and may vary with your application.

For starters you need to have the transmission already out and alone.  There are several great resources to aid you in removal of your transmission.  Here are just a few:

Paul Smith's A-413 Rebuild Page

Transmission Rebuild Page (Archived Version if site down)

Kelly-Mulhern Performance--Transmission Removal and Replacement Guide

Once you have the transmission out you need to remove the oil pump.  To remove it you can thread two bolts into the oil pump and remove it however you can.  Just a note, only two of the oil pump holes are threaded to aid in removal of the pump.

I removed my pump with materials readily available in my garage:

With the oil pump removed you can see the clutch packs and the input shaft.

In order to service both the front and rear clutch packs you need to remove the front band that holds the assembly in place.  In order to do that you must loosen or remove the kickdown bolt on the outside of the transmission.

Once you start to loosen this bolt the front band will also loosen.  Holding it in place is a strut that can fall.  Make sure you are watching this strut and ready to catch it so you don't loose it.

Once you have loosened the band sufficiently you can then remove the front band.

Now you can simply remove the two clutch assemblies.  Simply pull up on the input shaft.

With this assembly removed you can simply pull up on the front clutch assembly to separate it from the rear clutch assembly.

Here is a closeup of the rear clutch pack.

Both clutches are held in with a snap ring.  Both snap rings are to be removed with a screwdriver and does not require snap ring pliers.  The front clutch is held in with a wavy snap ring.  The rear clutch is held in with a sold snap ring.  The rear clutch has a selectable size snap ring to keep clearance in spec.  To measure clearance you must measure between the snap ring and the first steel plate.

Front Clutch

The front clutch does not have a user selectable snap ring. Recommended clearance is given in the FSM but probably can only be achieved (if out of spec) by replacing the clutches and steels.  Clearance on the 3 disc clutch, measured to the "farthest wave" of the wave washer, is 2.22 - 3.37 mm.  Clearance on the 4 disc clutch is 2.29 - 3.71 mm.

Rear Clutch

For 1990 the FSM recommends 0.67-1.10 mm (0.026-0.043 in) of clearance on the rear clutch.  After replacing the steels and friction plates you must measure the clearance and choose a snap ring that gets you within that clearance recommendation.  The following snap ring sizes are available from Mopar.  The following sizes are in inches.

Part Number     Size

4269670            .048 - .050"

1942421            .060 - .062"

1942422            .068 - .070"

4130774            .074 - .076"

1942423            .076 - .078"

4130775            .087 - .089"

5224439            .093 - .095"

*4539123           .097"

2538617            .098 - .100"               

*4539124           .110"

*Part number and size listed on Paul Smith's website.  Other numbers from Mopar parts manual.

To figure out your needed snap ring size obtain the following measurements.  First measure the currently used snap ring to obtain the Old snap ring size.  Next measure the clearance between the snap ring and the first steel in the clutch pack to obtain the User measured clearance.

Step 1)    New snap ring size - Old snap ring size = Measurement 1

Step 2)    User measured clearance - Measurement 1 = Possible New Clearance

Step 3)    Is the Possible New Clearance within the FSM recommended clearance?

If Yes, use that snap ring.

If No, Select another snap ring.

You want to try to get as close as you can to .067 mm of clearance. In my case I did not need to change snap rings as the clearance was within specs.

In addition to the above mentioned clutch packs and bands, there is a rear band located at the bottom of the transmission.  This band wraps around what is called an overrunning clutch.

I replaced the one found in my transmission but it was a pain.  If you don't suspect your rear band as slipping I would not recommend replacing it.  You can narrow down your transmission problems with a "Components in Use Chart."  One such chart can be found on Russ W. Knize's Minimopar site.  Unless you suspect the rear overrunning clutch or rear band as faulty I would stop the rebuild here.

Here, below the two clutch packs, are the front annulus and sun gears.  Pictured below is the output shaft thrust washer removed.

Pictured above is Output shaft thrust washer.  With the transaxle assembled, you can measure end play on the input shaft (you know the one that extends out of the bell housing) and make sure end play measures within the FSM amounts of .19 - 1.50 mm (.008 - .060 inch).  You can do this by changing the washer pictured above.  The following sized thrust washers are available:

Part Number        Size

5224039                1.98 - 2.03

5224040                2.16 - 2.21

5224041                2.34 - 2.39

Next, you may remove the external snap ring found below the thrust washer to remove the annulus and sun gears.  This is only necessary if you want to replace the rear band.  Again I would not recommend going further because removal of the overrunning clutch is easy, but installing it is harder.

Pictured above is the overrunning clutch.  Items 6 and 7 are freestanding in this clutch and are not attached in any way.  When you remove the overrunning clutch, eight springs (item 6) and eight rollers (item 7) may fall out.  When you go to re-install this clutch the only way to keep the rollers and springs from falling into the transmission is with a heavy grease.  Avoid removing this if at all possible.