Torque Specifications for 700-R4 Transmission Pan Boltsby Jack Hathcoat
While using a torque wrench to properly tighten 700-R4 transmission pan bolts is a good practice, it does not always guarantee a leak-free installation. This popular General Motors transmission is also prone to leaks around the pan because of distorted mounting bolt holes or the pan becoming warped because of improper installation. Setting the pan bolts to 12 foot-pounds of torque is only recommended after the pan is properly inspected and repaired.
Remove the Leaking Transmission Pan
Use a 13 mm socket and ratchet to remove the leaking transmission pan. Capture the fluid in a drain pan.
Clean the Gasket Surfaces
Scrape and wire-brush the gasket mounting surfaces on the transmission housing and transmission pan, then wipe them down with mineral spirits to remove any oil residue. Clean the bottom of the pan as well.
Straighten the Pan and Bolt Holes
Lay the mounting side of the pan on a flat surface, and make sure it is not warped. If it is severely warped, replace the pan. If one edge, or flange, is lightly warped, use a shop hammer to straighten it. Use a flat, round-headed punch to make sure all the bolt holes are perfectly flat and not distorted or stretched from over-tightening.
Glue on a New Gasket and Install the Pan
Apply a light coat of gasket sealer to the pan. Fit the new gasket in place, and allow the gasket to set. Place a flat, heavy object on top of the gasket to securely fix the gasket to the pan. Install the pan, and torque the bolts to 12 foot-pounds. Do not tighten the bolts in a linear fashion. Alternate side-to-side and end-to-end to ensure the pan is drawn into place evenly.
Jack Hathcoat has been a technical writer since 1974. His work includes instruction manuals, lesson plans, technical brochures and service bulletins for the U.S. military, aerospace industries and research companies. Hathcoat is an accredited technical instructor through Kent State University and certified in automotive service excellence.