GM Astro/Safari 1985-1996 Repair Guide

Front or Rear Shaft (Output) Seal



See Figures 1, 2 and 3

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Fig. Fig. 1: Exploded view of the front output shaft flange and seal

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Fig. Fig. 2: Extension housing (rear output shaft) seal alignment

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Fig. Fig. 3: Install the seal (front or rear) using a suitable driver or seal installation tool

  1. Raise and support the vehicle safely using jackstands. To help prevent the possibility of fluid leakage, the end of the vehicle at which the seal is being replaced should be lifted (raise the front if replacing the front seal, the rear for the rear seal).
  3. Matchmark the driveshaft and flange for installation purposes, then remove the front or rear driveshaft, as applicable.
  5. If replacing the front seal, remove the front output flange nut and washer, then remove the rubber sealing washer and the output flange.
  7. Pry out the output oil seal with a suitable prybar or seal removal tool being careful not to damage the seal bore.

To install:
  1. If replacing the rear seal, align the water drain hole in the output shaft oil seal with the drain groove in the extension housing.
  3. Lubricate seal lips with fresh Dexron®III or Dexron®II fluid.
  5. Install the seal to the transfer case assembly using a suitable driver or a seal installer such as J-367668-A.
  7. If you are replacing the front seal, install the front output shaft flange, rubber sealing washer, steel washer and flange nut. Tighten the nut to 80 ft. lbs. (108 Nm).
  9. Align and install the driveshaft.
  11. Check the transfer case lubricant by removing the fill plug (but remember that if the vehicle MUST be level so you may have to raise and support the other end as well, unless there is sufficient clearance with the vehicle completely lowered. If fluid does not spill out of the hole, add automatic transmission fluid (Dexron®III or Dexron®II, please refer to General Information & Maintenance for more details) to the fill hole until lubricant reaches the top of the hole.
  13. If not done earlier, remove the jackstands and carefully lower the vehicle.
  15. Check operation and inspect for leaks.