Tips and tricks for Chrysler switch valve plug testing - Transmission Digest

Tips and tricks for Chrysler switch valve plug testing

As technicians, we are often faced with build issues that can sometimes be frustrating at first. But with a little ingenuity, these frustrations can be turned around and made simple.

In 1989, Dodge came out with the first fully hydraulic electronic-solenoid shifting transmission, the A604 (no shift valves), which later became the 41TE. Originally, there were several issues that had to be worked through, but we now have entered an age in which most late-model transmissions are shifted through electronics.

Still, there are two different methods of controlling the shift, which are:

  1. Solenoids that control clutch feed oil being directed through the solenoid passageways seating switches — whether that takes the form of controlled switching from a checkball, or in the case of this discussion, separation of switch plugs.
  2. Solenoids that direct oil to a shifting “switch” valve (such as a valve or plug named 1-2 or 2-3 etc.) that directs the oil to the clutch it controls.

In this family of Dodge transmissions, switch plugs leaking can lead to issues ranging from pressure switch rationality codes—which are monitored through electronics—to burnt clutch assemblies that are being partially applied and smoking the clutches. Testing the bore fit of these plugs can sometimes be frustrating and often result in false answers when using conventional vacuum test procedures with a test plate (see Figure 1).

Figure 1.

A good friend, fellow builder and coworker recommended that this article be titled “Don’t get stiffed by the switch.” So, let’s make this simple!

An easy, effective solution is to make your own test tools (like those in Figure 2) using an OE (standard-size) plug as well as the oversized version of the plug (a larger aftermarket part installed after bore reaming to repair wear).

Figure 2.
Figure 2.

Keep in mind that there are two different sizes of switch plugs used with these units: .420-in. and .453-in. You’ll need to have one of each size OE valve handy. Here is a full list of everything needed to make test tools:

  • One standard .420” diameter OE switch plug.
  • One standard .453” dia. OE switch plug.
  • One oversized replacement switch plug being used. The one used here measures .473-in. dia. after ream.
  • A 1/8-in. quick-connect test fitting.
  • Measure the OE valve large spool diameter shown to verify which one you have (see Figure 3).

Here is the process:

  1. Using an OE plug (either a used one or a new direct replacement valve), drill a hole with a #21 drill or a drill that measures around 0.174-in. down the middle of the valve.
  2. Tap the newly drilled hole with a 10-32 thread tap to allow the use of the quick-connect test fitting (see Figure 4).
  3. Drill four holes in the oil grove at 12-, three-, six- and nine-o’clock positions in the valve using a 0.050-in. drill or smaller (see Figure 5). It is important to clean off the burrs from the drilling. It is not recommended to file the burrs; instead, use a simple scraping method (see Figure 6).
  4. Plug the open end of the center hole that was drilled and tapped by using a suitable plug or a cut end of a 10-32 screw (seal or glue the end of this tool shut). If silicone is used, be careful that it is in the open area of tool not blocking any of the four access holes. Make sure you have time to let the tool set and the silicone harden before use.
  5. Now, use the tool shown in Figure 7 to vacuum test the switch valve bore. It’s a simple way to get a very accurate test before and after every repair.
Figure 4.
Figure 4.
Figure 5.
Figure 5.
Figure 6.
Figure 6.
Figure 7.
Figure 7.

Thinking outside the box, you can be creative making homemade tools to ease testing as well as assembly issues. Truthfully, in my travels and teaching, I have not met any technician who doesn’t have an arsenal of homemade tools.

This article is just a simple example of making a tool that makes testing many Chrysler units a breeze. Always think, “how can I make this test easier?” Typically, you will do the rest!

Read more columns from the TASC Force Tips series here.

Randall Schroeder is a Sonnax technical support training specialist. He is a member of the Sonnax TASC Force (Technical Automotive Specialties Committee), a group of recognized industry technical specialists, transmission rebuilders and Sonnax technicians.

You May Also Like

Ford 8F24 mechanical diode failure

Mechanical diode failure in automatic transmissions is not uncommon. As far back as the AODE/4R70 shops have seen this type of failure. In April 2022 an article was published in Transmission Digest called, “The ins and outs of the Hydraulic Selectable One-Way Clutch (SOWC).” This article provided photos of the type of damage this style


Mechanical diode failure in automatic transmissions is not uncommon. As far back as the AODE/4R70 shops have seen this type of failure. In April 2022 an article was published in Transmission Digest called, “The ins and outs of the Hydraulic Selectable One-Way Clutch (SOWC).” This article provided photos of the type of damage this style diode is susceptible to in 9T50 and 8F35 transmissions.

Ford 8F35 maintenance tips: Planetary failure and no-pressure conditions

Our shop has had several vehicles come in with the Ford 8F35 transmission having planetary failure. Apparently, there was a run where the pinion needle bearings had a hardness problem (see Figure 1). Related Articles – Back with force: ATSG is back in full swing to educate the transmission industry – Don’t fear customer complaints about

Figure 12.
Don’t fear customer complaints about CVTs

Continuously Variable Transmissions, or CVTs, are more common than you think. Audi, Subaru, Nissan, Ford, GM and many other automakers use CVT transmissions in cars and SUVs. There is no way to avoid them. Chances are there is one in your shop right now. Related Articles – Powertrain industry directory and buyer’s guide 2024 –

Shift Pointers: A Chrysler 300 no-shift complaint

The case study has to do with a 2009 Chrysler 300 C 5.7L Nag1 RWD with 71,923 miles on it (see Figure 1, above). Related Articles – Shift of the shaft: Diagnosing Chrysler 48RE manual shaft issues – Sometimes, a diagnostic code is all you need – 10L80 and 10R80 pump gear differences It is

A guide to common GM, Ford and Nissan programming issues

One of the most common complaints I hear from shops when trying to install a new GM TCM is, “The module will not communicate.” While that might be partially true, by design they won’t communicate until they are programmed. If programming fails, there will be an “E” code set which will help you get to

Other Posts

Sonnax introduces drop-in 4-5-6 sleeved accumulator piston kit for GM 6T series

Sonnax has introduced a drop-in 4-5-6 sleeved accumulator piston kit (part no. 124740-68K). The company says users can recover hydraulic control and renew shift feel and performance in GM 6T70, 6T75, 6T80 (Gen. 2) transmissions by installing this kit. Related Articles – Schaeffler releases TorCon 6L80 torque converter – American Powertrain adds GearStar automatic transmissions

Sonnax introduces TCC apply limit switch valve kits for Chrysler RFE series

Sonnax has introduced a drop-in TCC apply limit switch valve kit for the Chrysler RFE series. Related Articles – Raybestos adds new Toyota UA80 / UB80 converter clutch plates – BendPak announces upgraded Litestix work light – Schaeffler offers new LuK clutch kits The company says you can limit the amount of pressure applied to the

Sonnax introduces GM 6L80, 6L90 output planet saver kits

Sonnax has introduced new output planet saver kits for GM 6L80 and 6L90 transmissions. The company says these kits can repair and prevent common concerns and save the planetary assembly when installed. Related Articles – Transtar to offer recycled engines – Alto introduces filters for GM 6L series – PRT launches 30 new complete strut

Sonnax introduces Smart-Tech clutch kit for GM 4L series

Sonnax has introduced a new Smart-Tech clutch kit for optimizing clutch capacity and guarding against clutch burnup in GM 4L60, 4L60-E, 4L65-E and 4L70-E transmissions. This kit (part no. 77734-01K) includes eight .067-in. BorgWarner high-energy frictions and seven .095-in. Lindered steels recommended for use with Sonnax Smart-Tech input housings. Related Articles – Force Control Industries