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Service bulletin 131201

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 id629619
Published by NHTSA2002-04-04
Manufacturer's number131201
Manufacturer's date2001-12-13
NHTSA componentPOWER TRAIN

NHTSA's summary

SUBJECT REGARDING SERVICE ENGINE SOON LIGHT ON, DELAYED TRANSMISSION DOWNSHIFT AND/OR EXCESSIVE FAN NOISE. *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

Vehicles listed
CHEVROLET TRAILBLAZER2002
GMC ENVOY2002
OLDSMOBILE BRAVADA2002

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

Recalls for the same vehicles and component
03V0750002003-03-06. POWER TRAIN:AUTOMATIC TRANSMISSION
20030482003-02-25. Powertrain
20012532001-10-22. Powertrain
20012522001-10-22. Powertrain
01V3340002001-10-17. POWER TRAIN:TRANSFER CASE (4-WHEEL DRIVE)
20012262001-09-05. Powertrain
01V2830002001-09-05. POWER TRAIN:TRANSFER CASE (4-WHEEL DRIVE)

A recall listed here may apply to some of the same vehicles. Only the manufacturer can say whether it applies to one vehicle.

Other bulletins for the same vehicles and component
24-NA-1412024-08-15. Service bulletin. GM is receiving damaged (cracked or broken) transmission cores returned to the reman facilities. The damage is being caused either in the removal process by the technician, or inadequate packaging or shipping. This bulletin advises the dealers to be more careful not to damage the transmissions during removal and to package the core properly for return.
PI1394B2024-02-02. Service bulletin. This PI bulletin advises the technician on the proper way to install the pistons in an engine.
23-NA-1532023-09-26. Service bulletin. The service bulletin advises the tech of a normal transmission shift condition and the delay in throttle response when the throttle plate is opened rapidly and advises the customer that it is normal for the delay.
PIP5640A2022-10-17. Service bulletin. This Preliminary Information communication provides information to the technician to not remove the torque converter bolts and start the engine as this may cause damage to the torque converter of the crankshaft on vehicles equipped with an automatic transmission.
22-NA-1812022-09-19. Service bulletin. This diagnostic tip advises the tech not to separate the flexplate from the torque convertor or damage my occur if the engine is started while diagnosing for noise from the engine or transmission.
PIP3366C2018-08-20. Service bulletin. This Preliminary information communicates to the dealer technician thatLight Duty Trucks equipped with automatic transmissions and 4 wheel drive may exhibit a condition of grinding/ratcheting type noise when shifting the automatic transmission into park while the transfer case is in 4 wheel drive low (4LO) range. Dealers technician's are advised this condition should be deemed a normal characteristic of 4WD low operation.
PIP3720D2017-08-15. Service bulletin. This Preliminary Information communication provides information to the technician with the axel setup information from American Axle Manufacturing. Technician should be advised that the maximum pinion shim to be used or stacked behind the pinion is 0.050?, and the minimum pinion shim is 0.020? for an 8.6 axle. The range for available pinion depth shims for the 10.5? axle is 0.006? to 0.024?. When setting the backlash it should be set between 0.003? to 0.005? on a new ring and pinion for any American Axle Manufacturing application. The ring and pinion can be reused or adjusted if the mileage is less than 500 miles, if not used for towing. Technician should be advised that a ?roller coaster? or ?hourglass? pattern on the bearings may be normal up to 10,000 miles and possibly longer. With a mis-machined housing you may get a heel pattern on both sides of the gear teeth at build up can generally be corrected with backlash adjustments. When setting up an 8.6? axle with a 5 cut gear set is to use a 0.035? pinion shim and set backlash to 0.004?. When using the newer 2 cut gear set also use a 0.035? pinion shim and still set backlash to 0.004?. To set the gear pattern use backlash to adjust the pattern heel to toe. Use the pinion shim to adjust the height of the pattern. The proper drive pinion bearing pre-load is from 15 - 30 inch pounds with new bearings. The total torque to turn after the differential case is installed should increase 5 - 10 inch pounds at the pinion. A new pinion nut must be used whenever the old one is removed. The axle shaft end play specification is 0.012? per side and the radial specification is 0.002? - 0.003?. Technician should be advised that synthetic lube can be used in all new American Axle Manufacturing axle assemblies. The new pinion seal for the 8.6? axle assembly is a two piece design.
PIP50722017-08-15. Service bulletin. This Preliminary Information communication provides information to the technician about vehicles that have slip in forward ranges immediately after replacing the input housing. Technician will inspect the 3-4 clutches and the forward clutch oil feed passages for leakage between circuits. Technician should apply regulated compressed air to the 3-4 clutch feed hole and the forward clutch feed hole one at a time with the input housing. Technician will need to replace the input housing if there is an air leak 3-4 clutches.
SB-070417001D2009-10-23. Service bulletin. GMC/BUICK/OLDSMOBILE/SAAB: BUMP OR THUMP NOISE IS HEARD COMING FROM THE REAR SUSPENSION OR FELT IN THE FLOOR. THE INFORMATION AFFECT VEHICLES WITH G67 AUTOMATIC LEVEL CONTROL REAR SUSPENSION. *PE UPDATED 3/30/11. *PE
PIT-47222008-12-18. Service bulletin. GMC: FLUID LEAK FROM TRANSMISSION OIL COOLER LINES DUE TO CORROSION. ALL 2000-2006 LIGHT DUTY TRUCKS EQUIPPED WITH THE LIGHT DUTY AUTOMATIC TRANSMISSION. *PE