Lube Nitro chromoly axle/birf’s (1 Viewer)

[aktundra]

Had Nitro chromoly front axles/birfs installed a year or so ago, that came with zerks.

Understand I should lube with moly, but wondering how much ? If I pump in grease, will it back out & “overflow” when full ? Can you over lube ?

 

[ppc]

You should open up the big square nut on the back side of the knuckle and and measure the amount of grease that is currently there with a zip-tie or similar. You want the cavity about 2/3rds full. You can overfill the knuckle to the point grease is forced through the seal into the diff. You can also visibly look at the backside of the knuckle to see at what level the grease is smeared on the ball. You should check the axle breather to make sure it is clear. If you find the knuckle has adequate grease and is not soupy then I would just put a half dozen pumps in via the birfield stub axle zerk and call it good.

 

[alia176]

You should open up the big square nut on the back side of the knuckle and and measure the amount of grease that is currently there with a zip-tie or similar. You want the cavity about 2/3rds full. You can overfill the knuckle to the point grease is forced through the seal into the diff. You can also visibly look at the backside of the knuckle to see at what level the grease is smeared on the ball. You should check the axle breather to make sure it is clear. If you find the knuckle has adequate grease and is not soupy then I would just put a half dozen pumps in via the birfield stub axle zerk and call it good.

Just wanted to clarify, the square nut is on top of the knuckle housing.

 

[jonheld]

I throw a few pumps at each side when I lube the driveshafts. Yes, you can "overfill", but the cavity is not air tight. You will lose a bit of grease every time you turn the steering wheel. That layer of grease helps seal the back side of the knuckle housing from crap getting in.
Grease good.
No grease, bad.
And there's no way to get an accurate reading using a zip tie or similar. All that tells you is that there's some grease in there.