Hummer H1 Geared Hub Input Seal

Geared Hub Output & Spindle Seal Article

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This is the seal where the halfshaft enters the geared hub. AMG has 2 types of seals. One consists of a set of 2 seals (hard and soft) and the other is a single hard seal. As of this writing (2/2005) the preferred seal is the one piece. If you get a 2 piece seal you can simply use the hard seal and seat it to the depth that the original seal was set. To use both you must remove the metal protector  (debris shield) ring on the halfshaft--it is pressed on and can be tapped off with a small hammer and a small screw driver. If you use both seals in the kit, it is *VITAL* that you follow the instructions and seat the main seal to the specified depth. The 'thick' side of the soft seal seats on the halfshaft, towards the CV joint. The thin edge faces the hub and main seal.

Halfshaft being pulled outThere are 2 seal kits. A one piece kit and a 2 piece kit. The 1 piece kit doesn't have the V seal. I've been told that the one piece kit is a military hmmwv part number. I ordered the seal from AMG in 4/2005 and received the 2 piece kit. It looks to me that the V seal is there to keep dirt away from the main seal.

Remove the halfshaft. If your halfshaft has metal dust shields take a screwdriver, pop them off and throw them away.

The picture shows the halfshaft being pulled out of the geared hub.

Note: My friend Jon from KY told me that all you have to do is undo the halfshaft bolt in the hub, remove the upper ball joint and pull the hub and shaft apart. This saves a ton of time because you don't have to remove the halfshaft.


Hummer input seals
2 Piece seal Kit AMG part number 5745324
Hummer H1 halfshaft
Cleanup the halfshaft & Stretch the V seal on. The surface of the halfshaft that contacts the input seal has to be smooth and not worn down to a smaller diameter or it's going to leak. You can polish any roughness with some fine #400 sandpaper. If the surface is chewed up or worn you have to replace the halfshaft or have a wear sleeve installed by a machine shop. Coat the surface with hub oil.
Hummer H1 geared hub input side
The input side of the Geared Hub

Seal, shim gasket and the rear side of the drive gear retainer

Press the sealI used an inexpensive seal tool from Harbor freight in a vise to press the seal into the retainer. The tool comes with a stack of different diameter disks and a large steel washer. If you don't have a seal installer you can place the old seal on top of the new seal and gently tap it in with a hammer. Make sure you keep the new seal square.

AMG has a special seal tool J-44905-A (handle part is J-8092) that presses the seal into the retainer the correct distance.

Seal RecessThe seal gets recessed .285 from the top surface in the 2 piece kit. AMG has a special tool for this but I was able to do it with a small ruler. The recess is there to compensate for the thickness of the V seal. The V seal is not that dimensionally precise that you need to get the main seal in within a thousandth of an inch.

If you have the one piece kit or don't want to use the V seal seat the main seal just below the chamfer on the edge of the drive gear retainer.

Note: On 2 piece seals: One piece is similar to the new seal and the 2nd piece is a rubber seal that is installed around the spindle sealing surface. When installing a new style seal make sure you remove this old 2nd piece. If you are using the 2 piece kit the second seal goes on with the thick side facing the large diameter studded part of the seal while the thin side faces the geared hub.

Seal installed in the drive gear retainer
The seal installed in the drive gear retainer

Cleanup the mating surface on the hub and install the shim gasket and drive gear retainer. Use thread locker and torque to 25 to 35 ft/lbs. Wet the seal with oil and reinstall the halfshaft. Check the oil level in the geared hub.