Transmission Fluid Fill Procedure

WARNING: This page is about a different car, the 2018 Chevrolet Suburban 3500 HD. However, it is still accessible from the selected car via links, so may be relevant.

Special Tools

DT-45096 Transmission Oil Cooling System Flush and Flow Test Tool
DT-45096-30 Transmission Cooler Flush Adapters
DT-45096-40 Transflow Oil Fill Adapter
DT-51190 Transmission Fluid Fill Adapter

For equivalent regional tools, refer to Special Tools .

CAUTION:

Use Dexron® HP transmission fluid only. Failure to use the proper fluid may result in transmission internal damage.

CAUTION:

Check the transmission fluid level immediately after adding fluid and before vehicle operation. Do not overfill the transmission. An overfilled transmission may result in foaming or fluid to be expelled out the vent tube when the vehicle is operated. Overfilling will result in possible damage to the transmission.

Check the transmission fluid level, refer to Transmission Fluid Level and Condition Check .

Fill Tube Plug Method

Fig 1: Fluid Fill Tube Plug And Oil Level Check Plug

Courtesy of GENERAL MOTORS COMPANY

CAUTION:

Use Dexron® HP transmission fluid only. Failure to use the proper fluid may result in transmission internal damage.

Based on accessibility, transmission fluid may be added through the fluid fill tube plug assembly (1) hole or through the oil level check plug (2) hole in the bottom of the transmission fluid pan.

CAUTION:

Before removing the transmission fluid fill tube plug assembly, thoroughly clean around the plug to prevent dirt or contaminants from entering the transmission during plug removal. Use compressed air to dislodge any caked dirt that may be stuck on and around the plug area. Use a mirror to confirm the area is free of dirt before removing the plug. Failure to clean around the plug may result in transmission contamination.

Clean around the fluid fill tube plug (1).

Fig 2: Plug Assembly

Courtesy of GENERAL MOTORS COMPANY

NOTE:

It may be necessary to use a long pair of 90 degree needle nose pliers to lift the plunger and remove the plug assembly.

Unlock the fill tube plug by lifting the plunger. Once the plunger is lifted, remove the entire plug assembly (1).
Determine the approximate amount of fluid needed to fill the transmission, based on the repair performed. Refer to Approximate Fluid Capacities . To avoid an under-fill condition, slightly overfill the transmission, and then allow the extra fluid to drain out through the oil level check plug during the transmission fluid level and condition check procedure.

Fig 3: Transflow Oil Fill Adapter And Test Tool

Courtesy of GENERAL MOTORS COMPANY

NOTE:

The DT-45096 flush and flow test tool is being utilized as a convenient method to pump the fluid into the bottom pan. A suitable hand pump may also be used instead. When using the DT-45096 flush and flow test tool, monitor the display panel to determine the amount of fluid being pumped from the tool supply tank into the transmission.

Using the DT-45096-40 transflow oil fill adapter (1) and the DT-45096 flush and flow test tool (2), or a suitable hand pump, add transmission fluid through the fill tube plug opening. Refer to Transmission Fluid Cooler Flow Test and Flushing (6L80 or 6L90)Transmission Fluid Cooler Flow Test and Flushing (Allison)Transmission Fluid Cooler Flow Test and Flushing (8L90)Transmission Fluid Cooler Flow Test and Flushing (10L80) for complete DT-45096 flush and flow test tool operating instructions. Use the FLOW position on the main function switch to pump the fluid.

CAUTION:

Check the fluid level. Refer to Transmission Fluid Level and Condition Check .

Check Plug Method

Fig 4: Oil Level Check Plug

Courtesy of GENERAL MOTORS COMPANY

CAUTION:

Use Dexron® HP transmission fluid only. Failure to use the proper fluid may result in transmission internal damage.

NOTE:

When the oil level check plug is removed with the engine OFF, transmission fluid may drain from the hole.

Remove the oil level check plug.

Fig 5: Fluid Fill Pan Adapter, Cooler Flush Adapter And Test Tool

Courtesy of GENERAL MOTORS COMPANY

Install the DT-51190 fluid fill pan adapter (1) and, if necessary, one adapter from the DT 45096-30 cooler flush adapters (2).
Determine the approximate amount of fluid needed to fill the transmission, based on the repair performed. Refer to Approximate Fluid Capacities . To avoid an under-fill condition, slightly overfill the transmission, and then allow the extra fluid to drain out through the oil level check plug during the transmission fluid level and condition check procedure.

NOTE:

Using the DT-51190 fluid fill pan adapter (1), DT-45096-30 cooler flush adapters (2), and the DT-45096 flush and flow test tool (3), add transmission fluid through the check plug hole. Refer to Transmission Fluid Cooler Flow Test and Flushing (6L80 or 6L90)Transmission Fluid Cooler Flow Test and Flushing (Allison)Transmission Fluid Cooler Flow Test and Flushing (8L90)Transmission Fluid Cooler Flow Test and Flushing (10L80) for complete DT-45096 operating instructions. Use the FLOW position on the main function switch to pump the fluid.

NOTE:

Failure to start the engine and move the shift lever through the gear ranges before removing the DT-51190 fluid fill pan adapter and DT-45096-30 cooler flush adapters from the bottom pan will result in an excess amount of fluid draining from the check plug hole. This may lead to an under-fill condition.

Start the engine and move the shift lever through each gear range. Pause for at least 3 seconds in each gear range.

CAUTION:

With the engine still running, remove the DT-51190 fluid fill pan adapter (1), (2), and DT-45096 flush and flow test tool (3) and then check the fluid level. Refer to Transmission Fluid Level and Condition Check .