Restoring a 1953 Mack firetruck and disassembling the front end. I'm thinking this is a stabilizer as it attaches to the frame and wheel and hub assembly by way of an adjustable linkage. The name of the part would be appreciated. They are both very stiff. I removed the vent cap and fill plug to find the grease was somewhat solidified. I heated the component and later washed the component with an acetone and brake fluid mix. Globs of oil and grease came out. Apparently, this is still dirty inside as I am on my 3rd washing and moving the arm back and forth creates a sucking sound and still blowing crud out both holes. The arm is pressed on a finely splined shaft with a spanner nut underneath that won't budge with a shop made spanner wrench. Do I need to remove the special spanner nut and clean the inside and inspect the inner working parts or just keep soaking until the the steering component shows clear cleaning solution. What type of oil is needed to be refill the reservoir and how do I measure how much oil is adequate. Thank you for any info you may have. Robert J. Walla retired Little Rock FD 501 993 5653 text or call.