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Service bulletin 990729004

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

The communication, as NHTSA indexes it (as of 2026-10-19)
TypeService bulletin
NHTSA id607589
Published by NHTSA1999-09-29
Manufacturer's number990729004
Manufacturer's date1999-08-01
NHTSA componentPOWER TRAIN:MANUAL TRANSMISSION

NHTSA's summary

SOME MEDIUM DUTY MODELS EQUIPPED WITH MANUAL TRANSMISSIONS MAY EXHIBIT A HIGH SHIFT EFFORT OR HARD SHIFTING CONDITION. *TT

The document

No address for NHTSA's copy can be built for this communication. Ask the dealer for it by the manufacturer's number.

Components

Transmission and driveline, Manual transmission

Vehicles listed
CHEVROLET T SERIES1997, 1998, 1999
GMC T SERIES1997, 1998, 1999

Listing a model year does not mean every vehicle of it is concerned: the document says which.

Other bulletins for the same vehicles and component
1602012001-05-21. Service bulletin. THIS MESSAGE CONCERNS CERTAIN 1997 THROUGH 2001 MEDIUM DUTY TRUCKS WITH SPICER SEVEN SPEED MANUAL TRANSMISSIONS EXHIBITING HEAVY VIBRATION THAT INCREASES WITH SPEED AND / OR AN OIL LEAK AND / OR A CRACKED ENGINE BLOCK. *TT
988371101998-08-04. Service bulletin. TECHNICIANS MAY EXPERIENCE DIFFICULTY IN REMOVING THE CONNECTORS FROM THE PARK/NEUTRAL POSITION SWITCH, USUALLY WHEN TRYING TO REMOVE THE SWITCH DURING TRANSMISSION SERVICE. *YC