A/T - Slipping/Loss of Drive Range

87chevy05

Number: 86-220

Section: 7A

Date: FEB.., 1987

Subject: SLIPPING/LOSS OF DRIVE RANGE THM 700-R4


Model and Year: 1982-86 PASSENGER CARS
AND TRUCKS WITH THM 700-R4 TRANSMISSIONS

TO: ALL CHEVROLET DEALERS

This bulletin cancels and supersedes Chevrolet Dealer
service Bulletin 86-124 (Section 7A) dated July, 1986.. All
copies of 86-124 should be discarded. New sprag, race,
and hub assemblies are available for use when servicing

1982-86 THM 700-R4 transmissions.

Slipping or loss of drive range condition on a 1982 through 1986 THM 700-R4 transmission may be caused by latching (chatter marks) of the forward clutch sprag assembly. This condition can result in belling or flaring of the reverse input housing and reaction sun shell. A new sprag, race and hub assembly is used in production and available for service.

Figure 1 - Transmission Identification Information:

July 17, 1986, Julian Date 198 (refer to figure 1) a new
sprag, race, and hub assembly was introduced for all 1987
THM 700-R4 transmission models, including 1987 Service
Replacement Transmission Assemblies (SRTA).

Figure 2 - Forward Clutch Sprag Assembly:

NOTE: When using the new sprag, race, and hub assembly, the sprag assembly wear plate (640) and the input carrier to race thrust washer (660) must be removed and not replaced (refer to Figure 2).

PARTS INFORMATION

APPLICATION PART NAME PART NUMBER
Corvette-All Sprag, Race, Hub Assy 8663773
Camaro 5.0L/5.7L Sprag, Race, Hub Assy 8663773
All other models Sprag, Race, Hub Assy 8663774