Tech - Trans Slips or May Not Go into Reverse (Repl. Piston). Chevrolet Cavalier 1999

Subject:

Transmission Slips Or May Not Go Into Reverse (Replace Piston)

Models:

1999 Chevrolet Cavalier

1999 Pontiac Sunfire

Built Prior to April 9, 1999 with 2.2L Engine (VIN 4 -- RPO LN2)

and Hydra-matic 3T40 Transaxle (RPO MD9)

Condition


(1)	Calendar Year
(2)	Julian Date
(3)	Serial Number
(4)	Model
(5)	Model Year
(6)	Transmission ID Location
(7)	VIN Location

Some owners of the above listed vehicles built prior to April 9, 1999 (Julian Date 099) may comment about a slip or no REVERSE condition. Initial slipping in REVERSE may not be evident until engine RPM is increased.

Cause


(647)	Ring, Front Differential Carrier Spacer Retainer
(648)	Bushing, Low and Reverse Clutch Housing
(649)	Housing Assembly, Low And Reverse Clutch
(650)	Ring, Low And Reverse Clutch Housing Retainer
(651)	Seal, Lip Low and Reverse Piston (Outer)
(652)	Seal, Lip Low and Reverse Piston (Inner)
(653)	Piston, Low and Reverse Clutch
(655)	Spring, Low and Reverse Clutch Release
(657)	Ring, Snap (Retainer)
(658)	Plate Assembly, Low and Reverse Clutch
(659)	Plate, Low and Reverse Clutch Backing (Selective)
(688)	Plate, Low and Reverse Clutch Waved
(688)	Plate, Low and Reverse Clutch Waved

This condition may be caused by an oversized low/reverse clutch piston (653). If the piston is oversized, during apply, the piston mayl interfere with the low/reverse clutch housing (649) limiting the piston's travel. This reduced travel could lead to a slipping condition or loss of REVERSE.

Correction

To correct this condition, measure the outside diameter of the low/reverse piston using a caliper. The largest piston diameter should not exceed 135.79 mm (5.346 in) as shown in the above illustrationn. If the measurement exceeds the dimension shown, replace the piston.

Refer to the 3T40 Section of the Transmission Unit Repair Manual for the proper replacement procedure.

Service Parts Information

Part Number	Description
08666659	Low/Reverse Piston

Parts are currently available from GMSPO.

Warranty Information

For vehicles repaired under warranty, use:

Labor Operation	Description	Labor Time
K7580	Clutch, Low and Reverse - Replace	Use Puublished Labor Operation Time