GM Astro/Safari 1985-1996 Repair Guide

Extension Housing Seal



See Figures 1, 2 and 3

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Fig. Fig. 1: Remove the driveshaft for access to the rear transmission (extension housing) seal

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Fig. Fig. 2: Use a seal puller to remove the extension housing seal (BE CAREFUL not to damage the bore)

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Fig. Fig. 3: Use a suitable driver to install the replacement seal into the housing

  1. Disconnect the negative battery cable for safety.
  3. Block the front wheels.
  5. Raise and support the rear of the vehicle safely using jackstands. Raise the rear of the vehicle sufficiently to keep all of the fluid in the transmission, away from the rear extension housing. If this cannot be done, the transmission pan will have to be removed in order to drain the fluid.
  7. Matchmark and remove the driveshaft as outlined in this section.
  9. Using a suitable prybar or better yet, a seal removal tool (these are usually inexpensive and make the job much easier), pry the rear seal out of the extension housing.

The use of an improper tool to pry the seal from the housing could allow the bore to be damaged, preventing the seal's replacement from fully "sealing'' the transmission. Fluid leaks could result.

To install:
  1. Coat the outside of the seal with a suitable non-hardening sealer.
  3. Install the new seal with a suitable driver or seal installer.