Transmission Adapter GM Thermo Block – Hose Connect (TAG1590H)


In-line GM Thermostat Block Adapter with Hose connections. New slotted back now allows this adapter to fit (5) GM transmissions, including the new 10-speed.

SKU: TAG1590H Category: Tags: ,
SKU: TAG1590H Category: Tags: ,
Features of Transmission Adapter GM Thermo Block – Hose Connect (TAG1590H):

Fits (5) GM transmissions including the new 10-speed with a single adapter. The fixed-dimension aluminum block-style adapter design requires (2) adapters for the same service coverage.
Fits the following GM transmissions. Requires use of the GM gasket on the transmission block. Some ports are slightly different diameters. Center in the gasket and tighten the adapter securely.

  • 6L80E
  • 6L90E
  • 8780E
  • 10L80 (1/2T 10 Sp)
  • 10L1000 (HD 10 SP)

Additional information

Weight 1 lbs
Service Instructions
  1. Turn off the vehicle and use the lift to access the side transmission block.
  2. Remove the transmission block and move the gasket to the TAG1590H adapter.
  3. Position gasket and brass adapter probes onto the two ports on the transmission block.
  4. Use a bolt to secure the adapter snuggly in place on the transmission. Please note that some transmissions have slightly larger ports and wider spacing. Center the adapter on the transmission before tightening.
  5. Attach to the transmission machine and service with the vehicle running in the “in-line” mode.
  6. When finished, remove the adapter, move the gasket back to the transmission block, and re-install the block on the transmission. Secure the block snuggly to GM-specified torque.


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