944 Automatic Transmission (Type 087) — Service & Overhaul Data

Service and overhaul reference for the 944's three-speed automatic transaxle, the Type 087 M (Europe / rest-of-world) and Type 087 N (USA / Japan) unit. This page collects the measured values and tightening torques you need for the deeper service jobs — the torque-converter seal, the axial-play adjustment, the valve body, the 2nd-gear brake and the governor — as a companion to the automatic transmission data page, which carries the ratios, ATF specification and the full torque list. It is an overview: read it to know the clearances and torques before you open the unit, not as a step-by-step overhaul. The end-float shim thicknesses and the 2nd-gear-brake distances are in millimetres and stay fixed; only the tightening torques switch between metric and imperial.

Warning: Never run the engine, and never let the car be towed, once the oil sump has been removed or the ATF drained — the transmission has no lubrication in that state.

Torque-converter oil seal

The seal at the converter (turbine-shaft) bore is prised out and a new one driven home with seal driver VW 192 (US 4450). The seal material is very soft and damages easily, so drive it squarely against its seat and take care not to nick the lip.

Caution: Never let the converter seal come into contact with gasoline or cleaning solvents — they attack the soft sealing material and ruin the new seal before it is even fitted.

Axial play — transmission to final drive

The axial play "y" between the automatic transmission and the final drive sets how far the ring gear can travel end-to-end, and it is adjusted with a selective shim (item 7, between the transmission bearing collar and the intermediate plate). You establish the required shim by measuring two distances with a straight-edge and a depth gauge, then reading the shim table.

Measuring points:

• a — final drive: from the case sealing surface to the bushing for the seals.
• b — automatic transmission: from the bearing collar for the shim to the intermediate plate, gasket in place.

Procedure:

1. Measure distance "a" on the final drive: lay the straight-edge across the case and measure down to the bushing, then measure down to the case sealing surface. The difference is "a" (worked example: 18.7 mm to bushing − 8.0 mm to sealing surface = 10.7 mm).
2. Measure distance "b" on the transmission: lay the straight-edge on the case and measure to the gasket, then to the bearing collar for the shim. The difference is "b" (worked example: 19.2 mm to gasket − 10.0 mm to bearing collar = 9.2 mm).
3. Subtract "b" from "a" to get the shim-selection distance "x" (worked example: 10.7 mm − 9.2 mm = 1.5 mm).
4. Select the shim from the table below. Shims are supplied in 0.4 mm and 1.2 mm thicknesses and are combined to make up the required pack.

Distance "x" (mm)	Shim
0.23 … 0.84	none
0.85 … 1.24	1 × 0.4 mm
1.25 … 1.64	2 × 0.4 mm
1.65 … 2.04	1 × 1.2 mm
2.05 … 2.44	1 × 0.4 mm + 1 × 1.2 mm
2.45 … 2.84	2 × 0.4 mm + 1 × 1.2 mm
2.85 … 3.24	2 × 1.2 mm
3.25 … 3.64	1 × 0.4 mm + 2 × 1.2 mm
3.65 … 3.88	2 × 0.4 mm + 2 × 1.2 mm

In the worked example x = 1.5 mm falls in the 1.25 … 1.64 mm band, so the pack is 2 × 0.4 mm.

Valve body — removing & installing

The valve body can be taken off with the transmission still in the car; it is reached by dropping the oil sump and the oil-filter screen. Note the position of the accumulator spring and piston as they come out.

• Drop the sump: the four sump bolts hold with lock washers — renew the washers if needed. Sump bolt torque 20.6 N·m15 ft·lb.
• The cover over the filter screen is held by two screws at 3.5 N·m3 ft·lb; renew the filter-screen gasket and the sump gasket on assembly.
• The valve body is held by eleven bolts with spring washers. On removal, unscrew the bolt shown in the workshop drawing last; on installation tighten all valve-body bolts alternately and uniformly to 3.5 N·m3 ft·lb.
• On refitting, engage the manual valve and the kickdown valve with their levers before drawing the body up.

Transfer & separation plates

On 1983-model-on transmissions the valve body is split by a transfer plate and a separation plate, secured by oval-head screws (3 for the accumulator support plate, 19 for the plate pack) all tightened uniformly to 3.5 N·m3 ft·lb. Note the check-ball arrangement before lifting the plates: five 6 mm balls and one 3 mm ball. The transfer plate carsries a cast-in part number and the separation plate is identified by its notch pattern, which differs by transmission code (RH; RCA/RCB/RCF; RCD/RCE) — record the notches so the correct plate goes back in the right place.

Valve body — disassembling & assembling

The valve body carries the shift and pressure valves in stacked bores closed by end plates; each end-plate screw torques to 3.5 N·m3 ft·lb and its washer is renewed if needed. Key points when it comes apart:

• Shift valve 1–2 spring and shift valve 2–3 spring are the same size — keep them separate so they do not get swapped.
• The main-pressure valve, main-pressure limiting valve and throttle-pressure limiting valve each have an adjusting screw that must not be turned — those pressures are set only on a test stand, so leave the screws exactly as found.
• Note the order of the throttle-pressure valve, converter-pressure valve, the 3–2 kickdown control valve, the apply valve for the 1st-and-reverse-gear brake, and the governor plugs (1–2 and 2–3) as they are withdrawn, and note the marks on the body so it reassembles the same way.

2nd-gear brake

When assembling the 2nd-gear brake, position the oil seals correctly and set the piston-rod distance "a" to match the direct-and-reverse (D+R) clutch fitted:

D+R clutch outer diameter	Distance "a"
134 mm	61.9 mm (±0.5 mm)
140 mm	52.4 mm (±0.5 mm)

The piston rod's later fixing is riveted to the piston with a disk (earlier a circlip); the riveted piston-and-disk must only go into the recessed cover, whose relief gives the piston disk the play it needs. Pay attention to piston-rod length. The brake band's adjustment nut torques to 19.6 N·m14 ft·lb.

Governor

The governor is a bolt-on assembly on the final-drive case (cover bolts 9 N·m7 ft·lb). Its two retaining screws torque to 3.5 N·m3 ft·lb, and the governor shaft to the governor housing also to 3.5 N·m3 ft·lb. Two service notes matter:

• The balance weight is balanced together with its own governor — do not swap it with the weight from a different governor.
• The governor shaft can be renewed separately; check the thrust plate for wear and position the transfer plate correctly on reassembly.