SYS.OK|MANUAL.DB● LIVE
HOMESERVICE MANUALSGMC1999FORWARD CONTROL 5.7 R, AUTOMATICREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 781 (AUTOMATIC TRANSMISSION, 4L60-E/4L65-E (TROUBLESHOOTING))TROUBLESHOOTINGTRANSMISSION FLUID CHECKING PROCEDURE
1999 GMC Forward Control 5.7 R, Automatic

Transmission Fluid Checking Procedure

1999 GMC Forward Control 5.7 R, AutomaticSECTION Transmission Fluid Checking Procedure
WARNING: This page is about a different car, the 2004 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.
Transmission Fluid Checking Procedure

Step Action Values Yes No
1
  1. Start the engine and allow the engine to idle until the transmission fluid temperature has reached the value specified.
  2. Depress the brake pedal and move the shift lever through the gear ranges, pausing a few seconds in each range. Return the shift lever to the PARK range.
  3. Raise the vehicle on a hoist. The vehicle must be level with the engine running and the shift lever in the PARK range. Refer to Lifting and Jacking the Vehicle in General Information.
    4. CAUTION: Refer to Checking Hot Transmission Fluid Through Drain Plug Hole Caution in Cautions and Notices.
  4. Remove the transmission plug.
    5. IMPORTANT: The transmission fluid may darken with normal use and does not always indicate contamination or oxidation.
  5. Check the fluid color. If necessary, use a small screwdriver as a dipstick.
Is the fluid color clear red or light brown with no burnt odor?		 30-50°C
(86-122°F)		 Go to Step 4  Go to Step 2 
2 Does the fluid have a burnt odor or a dark brown color? - Go to Step 8  Go to Step 3 
3 Does the fluid have a cloudy or milky appearance? - Go to Step 7  Go to Step 8 
4 Check the fluid level. The fluid level should be even with the bottom of the threaded plug hole.
Is the fluid level low?		 - Go to Step 5  Go to Step 11 
5 Add DEXRON III automatic transmission fluid in increments of 0.5 L until the fluid drains from the plug hole.
Did you add more than 1.5 L to the transmission?		 - Go to Step 6  Go to Step 11 
6 The transmission may have a leak. Refer to Fluid Leak Diagnosis .
Was a transmission fluid leak found?		 - Go to Step 9  Go to Step 11 
7 The transmission fluid is contaminated with engine coolant. Repair or replace the transmission cooler in the radiator.
Is the transmission cooler repair complete?		 - Go to Step 9  -
8
  1. Drain the fluid by removing the bottom pan.
    IMPORTANT: A very small amount of material in the bottom of the bottom pan is a normal condition.
  2. Check the bottom pan for any excessive debris.
Was excessive debris found?		 - Go to Step 9  Go to Step 10 
9
  1. Repair the transmission if required, in some cases, overhaul may be required.
  2. Flush the transmission oil cooler and pipes and check flow. Refer to Automatic Transmission Oil Cooler Flushing and Flow Test (J 45096)  or Automatic Transmission Oil Cooler Flushing and Flow Test (J 35944-A) .
  3. Add enough DEXRON III automatic transmission fluid to bring the fluid level to the bottom of the threaded plug hole.
  4. If equipped, reset the oil life monitor to 100%.
  5. Start the engine and allow the engine to idle until the transmission fluid temperature has reached the value specified.
  6. Depress the brake pedal and move the shift lever through the gear ranges, pausing a few seconds in each range. Return the shift lever to the PARK range.
  7. Raise the vehicle on a hoist. The vehicle must be level with the engine running and the shift lever in the PARK range. Refer to Lifting and Jacking the Vehicle in General Information.
    8. CAUTION: Refer to Checking Hot Transmission Fluid Through Drain Plug Hole Caution in Cautions and Notices.
  8. Remove the transmission plug.
  9. If needed, add DEXRON III automatic transmission fluid in increments of 0.5 L until the fluid drains from the threaded plug hole.
    10. NOTE: Refer to Fastener Notice in Cautions and Notices.
  10. Allow fluid to finish draining out of the plug hole. Install the plug and tighten to specified value.
  11. Wipe any excess fluid from the transmission with a rag or shop towel.
Is repair complete?		 30- 50°C
(86-122°F)
30 N.m
(22 lb ft)		 Go to Road Test Procedure  -
10
  1. Change the fluid and the fluid filter. Refer to Automatic Transmission Fluid/Filter Replacement .
  2. Start the engine and allow the engine to idle until the transmission fluid temperature has reached the value specified.
  3. Depress the brake pedal and move the shift lever through the gear ranges, pausing a few seconds in each range. Return the shift lever to the PARK range.
  4. Raise the vehicle on a hoist. The vehicle must be level with the engine running and the shift lever in the PARK range. Refer to Lifting and Jacking the Vehicle in General Information.
    5. CAUTION: Refer to Checking Hot Transmission Fluid Through Drain Plug Hole Caution in Cautions and Notices.
  5. Remove the transmission plug.
  6. If needed, add DEXRON III automatic transmission fluid in increments of 0.5 L until the fluid drains from the threaded plug hole.
    7. NOTE: Refer to Fastener Notice in Cautions and Notices.
  7. Allow fluid to finish draining out of the plug hole. Install the plug and tighten to specified value.
  8. Wipe any excess fluid from the transmission with a rag or shop towel.
  9. If equipped, reset the oil life monitor to 100%.
Is repair complete?		 30 N.m
(22 lb ft)		 Go to Road Test Procedure  -
11
    NOTE: Refer to Fastener Notice in Cautions and Notices.
  1. Allow fluid to finish draining out of the plug hole. Install the plug and tighten to specified value.
  2. Wipe any excess fluid from the transmission with a rag or shop towel.
Is repair complete?		 30 N.m
(22 lb ft)		 Go to Road Test Procedure  -
RENDER: 1.0x

NO RELATED

Recommended Tools & Savings

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Affiliate disclosure: We may earn a commission at no extra cost to you.

Shop Manual-Ready ToolsFree Quote CheckQuote Shield Pro

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.