Description

Chrysler NS, GS Service Manual – Transaxle & Power Transfer Unit

If you have ever had a transmission come apart on you because you guessed at a clutch pack clearance or used a torque spec from a forum, you know the feeling. That sinking moment when the case splits and parts scatter. The Chrysler NS, GS Service Manual is what you put on the bench to make sure that does not happen. 224 pages of factory procedure, zero interpretation. Every spec came from the Chrysler engineering floor, not from some scanner tool company’s intern.

This manual covers the 31TH three-speed automatic transaxle and the TE four-speed unit used in NS and GS platform vehicles. It is not a generic overhaul guide. It is the same document the dealer techs had, with the same torque values, same hydraulic test pressures, and same wiring diagrams. Page 2 reminds you to wear safety goggles when working on these transaxles. That is the level of detail – they tell you what to put on your face before you touch a line pressure port.

Transaxle and Power Transfer Unit Coverage

The table of contents starts with General Information for the 31TH transaxle: fluid level checks, selection of lubricant, pressure regulating valves, flow control valves, and special additives. Then it goes into Description and Operation – torque converter clutch, hydraulic control system, clutches, band servos, accumulator, pressure supply system, and the gearshift and parking lock controls governor. If you need to understand how the overrunning clutch works with the driving shell and sun gear, this section spells it out.

Diagnosis and Testing is where you live if you are trying to figure out why the transaxle slips or shifts hard. There are six hydraulic pressure tests – Test One (selector in 1), Test Two (selector in 2), Test Three (selector in D), Test Four (selector in Reverse), governor pressure, and throttle pressure. It also has clutch and servo air pressure tests for the front clutch, rear clutch, kickdown servo, low/reverse servo, and torque converter leakage. The manual includes TH Hydraulic Trouble Code Charts. You will not find those in a Chilton’s.

Torque Specifications – Why Factory Data Matters

The Specifications chapter lists the 31TH torque specifications. That is where you get the values for the valve body bolts, oil pump housing, front pump oil seal retainer, transfer shaft bearing retainer, differential bearing cap bolts, and the torque converter drain plug. I have seen a differential come loose because someone used a generic value of 35 ft-lb when the factory spec was 23 ft-lb with Loctite. That is a failure that takes the whole case with it. This manual gives you the correct numbers. No guesswork.

Torque is not the only thing. The manual also covers band adjustment procedures – the kickdown band (front) and the low/reverse band (rear). It includes the bearing adjustment procedures for the output shaft, differential, and transfer shaft, complete with a differential bearing shim chart. If you are setting pinion depth or preload, you need those charts.

Does This Manual Cover Wiring?

Yes. The Diagnosis and Testing section includes the torque converter clutch solenoid wiring connector. For the TE four-speed transaxle, the manual covers the Transmission Control Module, solenoids, sensors, and on-board diagnostics. The Schematics and Diagrams chapter has the TH transaxle hydraulic schematic, but the wiring for the Park/Neutral Starting and Back-Up Lamp Switch is also documented in the Removal and Installation section. If you are troubleshooting a no-start because of the neutral safety switch or a missing reverse light, the test procedure is there. For a full electrical diagram of the entire vehicle, you will want the Chrysler NS GS Wiring Diagram which pairs with this service manual.

3 Sections That Save You Real Time

Service Procedures. This covers flushing coolers and tubes, fluid and filter change, fluid drain and refill, cooler flush using Tool 6906 or suction gun and mineral spirits, aluminum thread repair, and oil cooler flow check. If you are swapping a transaxle, you need to flush the cooler. Skipping that step kills the replacement in 500 miles.

Disassembly and Assembly. Step-by-step for the entire transaxle – front pump oil seal, valve body recondition, oil pump recondition, front and rear clutch recondition, front planetary and annulus gear, low/reverse servo, accumulator, kickdown servo, transfer shaft repair (including determining shim thickness), parking pawl, output shaft repair, and differential repair. Each operation has its own inspection criteria. For example, the front clutch recondition section tells you how to measure the spring force and check the steel plates for warpage. That is the kind of information that keeps a rebuilt unit from failing.

Adjustments. Gearshift cable adjustment, throttle pressure linkage adjustment, line pressure adjustment, rod adjustment procedure, band adjustments, and bearing adjustments. The hydraulic control pressure adjustments include rod adjustment procedure – you have to get the geometry right or the throttle pressure will be off and the shifts will feel like a hammer hit.

Related manuals for your NS/GS: Chrysler NS GS Service Manual – Tires & Wheels OEM Factory Guide and Chrysler NS, GS 1997 Service Manual – Factory OEM Repair Guide are available for the rest of the vehicle. For background on automatic versus Manual Transmission systems, the differences in diagnosis are significant.

Does this manual cover the 31TH transaxle only or also the TE four-speed?

Both the 31TH three-speed and the TE four-speed are covered in separate sections within the same 224-page PDF.

What torque specs are included?

The Specifications chapter lists the 31TH torque specifications. That includes valve body bolts (typically 12-15 ft-lb depending on bolt location), front pump housing bolts, converter drain plug, transfer shaft nut, differential bearing cap bolts, and the parking pawl pivot pin. But you cannot just take those numbers and use them on every bolt. The manual also gives the tightening sequence for the front pump and the valve body, which matters because an uneven clamp load warps the aluminum. Additionally, the band adjustment specs are given inch-lb and then the number of turns out. For the kickdown band, you tighten the adjusting screw to 5.9 N·m (52 in-lb) then back it off exactly 2 1/2 turns. That kind of detail only comes from the factory. You also get the torque converter clutch solenoid wiring connector torque spec (10 N·m) and the park/neutral switch mounting bolt torque (7 N·m). If you are assembling a differential, the bearing preload shim charts tell you which shim to install based on the measured torque. There is a reason this manual is 224 pages – they do not skip anything.

When you are pulling a transaxle on an NS or GS, you need the factory data. Not a summary, not a reprint from a third party. Original Chrysler documentation. Access the Factory Manual.