How to Check Automatic
Transmission Fluid
Because this operation can be a little difficult, you maychoose to have this done at the dealer/retailer servicedepartment.
If you do it yourself, be sure to follow all the instructionshere or you could get a false reading on the dipstick.
Notice:Too much or too little fluid can damageyour transmission. Too much can mean that someof the fluid could come out and fall on hot engineparts or exhaust system parts, starting a fire.Too little fluid could cause the transmission tooverheat. Be sure to get an accurate reading if youcheck your transmission fluid.
Wait at least 30 minutes before checking thetransmission fluid level if you have been driving:
•When outside temperatures are above 32°C (90°F).
•At high speed for quite a while.
•In heavy traffic — especially in hot weather.
•While pulling a trailer.
To get the right reading, the fluid should be atnormal operating temperature, which is 82°C to 93°C(180°F to 200°F).
Get the vehicle warmed up by driving about 24 km(15 miles) when outside temperatures are above10°C (50°F). If it is colder than 10°C (50°F), you mayhave to drive longer.
Checking the Fluid Level
Prepare the vehicle as follows:
1. Park the vehicle on a level place. Keep the enginerunning.
2. With the parking brake applied, place the shift leverin P (Park).
3. With your foot on the brake pedal, move the shiftlever through each gear range, pausing for aboutthree seconds in each range. Then, positionthe shift lever in P (Park).
4. Let the engine run at idle for three to five minutes.
Then, without shutting off the engine, follow these steps:
1. Locate the transmission fluid cap which is locatednext to the radiator hose and below the engine aircleaner/filter assembly on the driver side of thevehicle. The cap is marked TRANS FLUID.SeeEngine Compartment Overview on page 6-12for more information on location.
2. After removing the engine air cleaner/filter assemblyto reach the transmission fluid cap, turn the capcounterclockwise to remove. Pull out the dipstickand wipe it with a clean rag or paper towel.
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(E) Tire Ply Material:The type of cord andnumber of plies in the sidewall and underthe tread.
(F) Uniform Tire Quality Grading (UTQG):Tiremanufacturers are required to grade tiresbased on three performance factors: treadwear,traction and temperature resistance. For moreinformation seeUniform Tire Quality Grading onpage 6-67.
(G) Maximum Cold Inflation LoadLimit:Maximum load that can be carried and themaximum pressure needed to support thatload. For information on recommended tirepressure seeInflation - Tire Pressure on page 6-54andLoading the Vehicle on page 5-18.
(A) Temporary Use Only:The compact spare tireor temporary use tire has a tread life ofapproximately 3,000 miles (5 000 km) and shouldnot be driven at speeds over 65 mph (105 km/h).The compact spare tire is for emergency use whena regular road tire has lost air and gone flat.SeeSpare Tire on page 6-90andIf a Tire GoesFlat on page 6-70.
Compact Spare Tire Example
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Load Index:An assigned number ranging from1 to 279 that corresponds to the load carryingcapacity of a tire.
Maximum Inflation Pressure:The maximum airpressure to which a cold tire can be inflated. Themaximum air pressure is molded onto the sidewall.
Maximum Load Rating:The load rating for a tireat the maximum permissible inflation pressurefor that tire.
Maximum Loaded Vehicle Weight:The sum ofcurb weight, accessory weight, vehicle capacityweight, and production options weight.
Normal Occupant Weight:The number ofoccupants a vehicle is designed to seat multipliedby 150 lbs (68 kg). SeeLoading the Vehicle onpage 5-18.
Occupant Distribution:Designated seatingpositions.
Outward Facing Sidewall:The side of anasymmetrical tire that has a particular side thatfaces outward when mounted on a vehicle. Theside of the tire that contains a whitewall, bearswhite lettering, or bears manufacturer, brand,and/or model name molding that is higher or deeperthan the same moldings on the other sidewall ofthe tire.
Passenger (P-Metric) Tire:A tire used onpassenger cars and some light duty trucks andmultipurpose vehicles.
Recommended Inflation Pressure:Vehiclemanufacturer’s recommended tire inflationpressure as shown on the tire placard. SeeInflation - Tire Pressure on page 6-54andLoadingthe Vehicle on page 5-18.
Radial Ply Tire:A pneumatic tire in which theply cords that extend to the beads are laid at90 degrees to the centerline of the tread.
Rim:A metal support for a tire and upon whichthe tire beads are seated.
Sidewall:The portion of a tire between the treadand the bead.
Speed Rating:An alphanumeric code assigned toa tire indicating the maximum speed at which atire can operate.
Traction:The friction between the tire and theroad surface. The amount of grip provided.
Tread:The portion of a tire that comes intocontact with the road.
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A Tire and Loading Information label is attached tothe vehicle’s center pillar. This label lists yourvehicle’s original equipment tires and shows thecorrect inflation pressures for your tires when theyare cold. The recommended cold tire inflationpressure, shown on the label, is the minimumamount of air pressure needed to supportyour vehicle’s maximum load carrying capacity.
For additional information regarding how muchweight your vehicle can carry, and an example ofthe Tire and Loading Information label, seeLoading the Vehicle on page 5-18. How you loadyour vehicle affects the vehicle handling andride comfort, never load your vehicle with moreweight than it was designed to carry.
When to Check
Check your tires once a month or more. Do notforget to check the spare tire. If your vehicle has acompact spare tire, it should be at 60 psi (420 kPa).For additional information seeSpare Tire onpage 6-90.
How to Check
Use a good quality pocket-type gage to check tirepressure. You cannot tell if your tires areproperly inflated simply by looking at them. Radialtires may look properly inflated even when theyare under-inflated. Check the tire’s inflationpressure when the tires are cold. Cold means yourvehicle has been sitting for at least three hoursor driven no more than 1 mile (1.6 km).
Remove the valve cap from the tire valve stem.Press the tire gage firmly onto the valve toget a pressure measurement. If the cold tireinflation pressure matches the recommendedpressure on the Tire and Loading Informationlabel, no further adjustment is necessary. If theinflation pressure is low, add air until you reach therecommended amount.
If you overfill the tire, release air by pushing onthe metal stem in the center of the tire valve.Re-check the tire pressure with the tire gage.
Be sure to put the valve caps back on the valvestems. They help prevent leaks by keeping out dirtand moisture.
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If your vehicle has P235/55R17 or P245/50R18 sizetires, and you will be driving at speeds of 100 mph(160 km/h) or higher, where it is legal, set the coldinflation pressure to the maximum inflation pressureshown on the tire sidewall, or 38 psi (265 kPa),whichever is lower. See the example following.
Example:
You will find the maximum load and inflation pressuremolded on the tire’s sidewall, in small letters, nearthe rim flange. It will read something like this: Maximumload 690 kg (1521 lbs) 300 kPa (44 psi) Max. Press.
For this example, you would set the inflation pressure forhigh-speed driving at 38 psi (265 kPa).
When you end this high-speed driving, return the tires tothe cold inflation pressure shown on the Tire andLoading Information label. SeeLoading the Vehicle onpage 5-18.
Tire Pressure Monitor System
The Tire Pressure Monitor System (TPMS) uses radioand sensor technology to check tire pressure levels. TheTPMS sensors monitor the air pressure in yourvehicle’s tires and transmit tire pressure readings to areceiver located in the vehicle.
Each tire, including the spare (if provided), should bechecked monthly when cold and inflated to the inflationpressure recommended by the vehicle manufactureron the vehicle placard or tire inflation pressure label.(If your vehicle has tires of a different size than the sizeindicated on the vehicle placard or tire inflationpressure label, you should determine the proper tireinflation pressure for those tires.)
As an added safety feature, your vehicle has beenequipped with a tire pressure monitoring system (TPMS)that illuminates a low tire pressure telltale when oneor more of your tires is significantly under-inflated.
Accordingly, when the low tire pressure telltaleilluminates, you should stop and check your tires assoon as possible, and inflate them to the properpressure. Driving on a significantly under-inflated tirecauses the tire to overheat and can lead to tire failure.Under-inflation also reduces fuel efficiency and tiretread life, and may affect the vehicle’s handlingand stopping ability.
Please note that the TPMS is not a substitute for propertire maintenance, and it is the driver’s responsibility tomaintain correct tire pressure, even if under-inflation hasnot reached the level to trigger illumination of theTPMS low tire pressure telltale.
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GM’s exclusive TPC Spec system considers over adozen critical specifications that impact the overallperformance of your vehicle, including brake systemperformance, ride and handling, traction control, and tirepressure monitoring performance. GM’s TPC Specnumber is molded onto the tire’s sidewall near the tiresize. If the tires have an all-season tread design,the TPC Spec number will be followed by an MS formud and snow. SeeTire Sidewall Labeling on page 6-47for additional information.
GM recommends replacing tires in sets of four. This isbecause uniform tread depth on all tires will helpkeep your vehicle performing most like it did when thetires were new. Replacing less than a full set of tires canaffect the braking and handling performance of yourvehicle. SeeTire Inspection and Rotation on page 6-62for information on proper tire rotation.
{WARNING:
Mixing tires could cause you to lose control of
your vehicle while driving. If you mix tires of
different sizes, brands, or types (radial and
bias-belted tires), the vehicle may not handle
properly, and you could have a crash. Using tires
of different sizes, brands, or types may also cause
damage to your vehicle. Be sure to use the correct
size, brand, and type of tires on all wheels.
Your vehicle may have a compact spare tire and
wheel assembly. If the vehicle has a compact
spare tire and wheel, they have the same overall
diameter as your vehicle’s full-size tires and
wheels. Because they were designed and
developed for use on your vehicle, it is all right to
drive your vehicle with the compact spare installed
properly. Compact spare tires are designed for
temporary use only. SeeSpare Tire on page 6-90.
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Uniform Tire Quality Grading
Quality grades can be found where applicable onthe tire sidewall between tread shoulder andmaximum section width. For example:
Treadwear 200 Traction AA
Temperature A
The following information relates to the systemdeveloped by the United States National HighwayTraffic Safety Administration (NHTSA), whichgrades tires by treadwear, traction, andtemperature performance. This applies only tovehicles sold in the United States. The grades aremolded on the sidewalls of most passenger cartires. The Uniform Tire Quality Grading (UTQG)system does not apply to deep tread, winter-typesnow tires, space-saver, or temporary usespare tires, tires with nominal rim diameters of10 to 12 inches (25 to 30 cm), or to somelimited-production tires.
While the tires available on General Motorspassenger cars and light trucks may vary withrespect to these grades, they must also conformto federal safety requirements and additionalGeneral Motors Tire Performance Criteria (TPC)standards.
Treadwear
The treadwear grade is a comparative ratingbased on the wear rate of the tire when testedunder controlled conditions on a specifiedgovernment test course. For example, a tiregraded 150 would wear one and a half (1.5) timesas well on the government course as a tiregraded 100. The relative performance of tiresdepends upon the actual conditions of their use,however, and may depart significantly fromthe norm due to variations in driving habits, servicepractices, and differences in road characteristicsand climate.
Traction – AA, A, B, C
The traction grades, from highest to lowest, areAA, A, B, and C. Those grades represent the tire’sability to stop on wet pavement as measuredunder controlled conditions on specifiedgovernment test surfaces of asphalt and concrete.A tire marked C may have poor tractionperformance.
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Temperature – A, B, C
The temperature grades are A (the highest), B,and C, representing the tire’s resistance tothe generation of heat and its ability to dissipateheat when tested under controlled conditions on aspecified indoor laboratory test wheel. Sustainedhigh temperature can cause the material of the tireto degenerate and reduce tire life, and excessivetemperature can lead to sudden tire failure.The grade C corresponds to a level of performancewhich all passenger car tires must meet underthe Federal Motor Vehicle Safety StandardNo. 109. Grades B and A represent higher levelsof performance on the laboratory test wheelthan the minimum required by law. It should benoted that the temperature grade for this tireis established for a tire that is properly inflated andnot overloaded. Excessive speed, underinflation,or excessive loading, either separately or incombination, can cause heat buildup and possibletire failure.
Wheel Alignment and Tire Balance
The tires and wheels on your vehicle were alignedand balanced carefully at the factory to give you thelongest tire life and best overall performance.Adjustments to wheel alignment and tire balancing willnot be necessary on a regular basis. However, ifyou notice unusual tire wear or your vehicle pulling toone side or the other, the alignment might need tobe checked. If you notice your vehicle vibrating whendriving on a smooth road, the tires and wheelsmight need to be rebalanced. See your dealer/retailerfor proper diagnosis.
Wheel Replacement
Replace any wheel that is bent, cracked or badly rustedor corroded. If wheel nuts keep coming loose, the wheel,wheel bolts and wheel nuts should be replaced. If thewheel leaks air, replace it. Some aluminum wheels cansometimes be repaired. See your GM dealer/retailer ifany of these conditions exist.
Your GM dealer/retailer will know the kind of wheelyou need.
Each new wheel should have the same load-carryingcapacity, diameter, width, offset and be mountedthe same way as the one it replaces.
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