Although my 49 steers precisely and easily, with no play or looseness at the steering wheel, my ’49’s steering gear box has always had a slow leak. I put a new gasket on the end cover a couple of years ago, but it did not improve things. Annoyingly, every month or so I’ve had to top it up.
After reading a CLC Forum thread on this subject and mulling over the suggested alternatives (all of which involve thicker oil or grease), I bought a ½ liter plastic bottle of Penrite Steering Box Lube for Vintage Cars (for anything without rack and pinion steering or power steering), an Australian-made flowable grease. It is sold in the U.S. by Restoration Supply Company in California and costs $17 per bottle, plus about $10 shipping. I ordered 2 bottles. When they arrived, I raised the front wheels off the ground, took off the left front wheel to provide better access to the steering box, and drained the oil from the steering box by removing the lower inboard bolt on the end cover. After replacing the bolt, I then removed the filler plug and squirted lube into the box by squeezing the bottle. To get it to settle in the box I had to turn the steering wheel from side to side a couple of times between squirts. One bottle was not enough to fill the box completely, so I had to use part of the 2nd bottle. It took several days before the lube totally settled, so I checked the box after every drive and topped it up. The box no longer leaks.