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Steering knuckle lube

Posted: Wed Jul 02, 2025 12:36 pm
by shrinx
The technical manual says to remove the plug at the bottom of the steering knuckle then shoot grease in from the top. I can find the top zerk fitting but the bottom plug is a mystery. If the plug is that bump among the four bolts securing the plate (see photo), there is no way to remove it. I'm stumped and/or confused as to the location of the plug. Help please.
Terry
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Re: Steering knuckle lube

Posted: Wed Jul 02, 2025 12:55 pm
by PoW
That one gets grease via the Zerk in the axle housing bell via gravity. Essentially pump that baby full till it oozes a bit out the felt seals.

The internal shaft seal always leaks a bit of gear oil in there, too. Messy, but it keeps things from wearing out.

PoW

Re: Steering knuckle lube

Posted: Wed Jul 02, 2025 2:22 pm
by John Mc
If that photo is a picture from the bottom looking up, then the nice shiny grease zerk near the top of the photo is actually in the hole where the plug should go. The plug should be in that hole when driving, not the zerk.

The lube order says to remove that plug and grease from the top until grease comes out the hole in the bottom (TM 9-8030 pg 62, figure 34, Note 6, also appearing in the newer LO 9-2320-212-12 in note 6). While the lube order is clear about greasing from the top, I've had a couple of knowledgeable people say to remove the zerk from the top and screw it in where the plug normally goes, greasing from the bottom until it comes out the top. When done, remove the zerk from the bottom, replace the plug there, and put the zerk back in the top. (Basically, they use the top hole as a convenient place to store the zerk until needed, then remove it when greasing to give an indication of grease level.)

I'm not an expert on these trucks, so don't take my word for it. I've been greasing from the bottom with good results. Hopefully someone more knowledgeable will chime in.

Re: Steering knuckle lube

Posted: Thu Jul 03, 2025 1:25 am
by Cal_Gary
I'll post a picture later today. Nam Vet had one out here but it now errors off.
Gary

Re: Steering knuckle lube

Posted: Thu Jul 03, 2025 8:10 pm
by Cal_Gary
Here you go:
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IMG_2002.JPG (100.03 KiB) Viewed 36 times

Re: Steering knuckle lube

Posted: Fri Jul 04, 2025 6:51 am
by John Mc
Gary - your plug looks a little different than I remember mine. Now I'm curious: I'll have to go look.

Re: Steering knuckle lube

Posted: Fri Jul 04, 2025 12:29 pm
by shrinx
Thank you for the assistance. I'm going to climb under the axle after a three week vacation (with no grease) and see what's what.