EXPERTEC TSB (87-T-36)

Publication date: 1987-04-03
Reference number: 87-T-36

EXPERTEC TSB

TECHNICAL SERVICE BULLETIN

Reference Number(s): 87-T-36, Date of Issue: 04/03/87

SECOND GEAR STARTS - DIAGNOSIS FOR GOVERNOR CIRCUIT

Model(s): 1984-87 Oldsmobile Models with THM 440-T4 Transaxles

Bulletin No.: Oldsmobile 87-T-36

Date: 04/03/1987

BULLETIN ILLUSTRATION LIST

Fig 1: Graphic

Fig 2: Graphic

Fig 3: Graphic

BULLETIN COVERS

A 1984-87 vehicle equipped with a THM 440-T4 (Fig 1 ) may start out in 2nd gear instead of 1st gear. This condition could occur intermittently or all the time.

SERVICE ACTION

High line pressure could be a cause by holding too much governor pressure and not allowing the 1-2 shift valve to downshift. Check line pressure and governor pressure. Governor pressure should be below 3.0 PSI at 0 mph.

If governor pressure is okay, the 1-2 shift valve (331) may be stuck in the upshifted position. Remove the control valve assembly and check for a sticking 1-2 shift valve (331),1-2 throttle valve (332), or the 1-2 throttle valve spring (333) caused by the 1-2 throttle valve bushing retainer (390) pushed in too far. The retainer should be installed flush with the machined surface of the valve body. (Fig 2 )

SERVICE MANUAL REFERENCE

Refer to the THM 440-T4 (ME9) automatic transaxle unit repair section in the appropriate service manual.