Oil & Grease Leaks


By E. Meloan

(This article was originally published in the March, 2000 issue of the Spark Coil.)

Howdy Fellow Model T’ers!  This issue we’ll talk a little about oil and grease leaks in our T’s.  Henry Ford was quoted as saying, “If it isn’t dripping, it’s out of oil.”  I guess that’s true but it’s always nice not to leave a large black oil spot when we drive away from a parking spot!

Let’s start at the front and work our way back.  The front seal around the crankshaft is almost always a culprit when looking for leaks.  This results in oil on the fan belt which looks bad and causes slipping and earlier failure of the belt.  Stopping this leak requires removal and disassembly of the engine! One suggestion to keep the oil off the belt is to remove the crank pulley and slip one or two of the felt washers used in the rear axle bearing cap over the crankshaft then replace the pulley.

Got drips from the pan bolts?  There are a couple of easy fixes that work well.  A few turns of string around the bolt before you tighten it will act as a seal to keep the oil where it belongs.  Several of the T parts suppliers sell a package of plastic washers which will also do the job nicely.  The assortment includes the pan bolts, hogshead cover screws, and rear end grease plug.

Our next potential leak is the felt seal around the front of the transmission cover (hogshead).  About as many methods as there are Model T’s have been tried over the years.  Be careful about using extra felts because this can force the cover out of alignment which can pull the crankcase out of line!  Careful use of gasket sealer will usually work.  Put a heavier application of sealer at the two corners where the felt joins the cork side gaskets.  That’s always a trouble spot for leaks.

While we’re in this area…  Check the four screws that hold the starter bendix cover on.  They must be tight!  If loose. They will leak oil and they may come out allowing the cover to come off.  If that happens, you will lose ALL your oil in a minute or two!  Henry didn’t put lock washers on these four screws but I would suggest that we should!

The pedal shafts are another potential leak area.  There really is no provision inside the hogshead to prevent oil from working out around the three shafts.  The more they are worn, the more they will leak!  The early aluminum covers, being softer, are quicker to wear and so are very likely to leak badly.  One suggested fix is to remove the cams and make a small inset in the side that bolts against the cover.  Place a rubber “O” ring in the inset, slide the shaft through and rebolt on the cover.

The “4th main bearing” at the rear of the transmission cover is a possible source of oil drips right in front of the universal joint.  Make sure the gaskets between the rear cap and the universal joint cap are in place on BOTH sides of the cap and the bolts are tight.

Let’s talk about rear wheel grease leaks…  By far the largest cause of messy grease leaking out around the axles in too much grease in the differential!  A very small amount of 600 weight grease is needed.  The ring gear will pick it up and throw it around.  You should not have grease up to the level of the filler hole.  An inch and a half or two inches deep is enough.

If you notice grease leaking on the driver side rear wheel but not on the passenger side,  check the end play in the axles.  Jack up the rear end and see how much you can move the axles in and out.  Chances are you’ll find quite a bit of play.  When this happens, the ring gear is pushed toward the driver side wheel on every right turn and it acts like a pump to push grease into the left axle housing.

Does your T make differential grease?  If so, you’ve got engine oil leaking past the 4th main and down the toque tube into the rear end.  Keeps the drive shaft bearings lubricated but it’s eventually going to come out the axle ends!

Got something you’d like discussed? Let me know.