Hey guys, just wanted to hear what people suspect this could be. About a month ago we did our knuckle rebuild with the kit from cruiser outfitters. Everything has been great. Put up a little over 3,000 miles since then. No signs of any leaking anywhere else and the steering arm bolts are still torqued to spec. What could this be? Both sides had small drop formations at the bottom of the bolts like it was a small leak but no drops left behind after parking anywhere.
Diff Fluid on Steering Arm after Knuckle Rebuild
- Thread starter verseddreams
- Start date
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CrabCake
SILVER Star
Yeah, I wouldn't worry about it yet, especially if it's about the same on both sides. You could pop the fill plug out of the top and dip a zip tie or the like down into the birf grease to make sure that it's not liquified by intrusion of diff oil for piece of mind. If you dip it and it's still nice and tacky, no worries!
Yup, that's oil separated from the grease. When it's birf soup, trust me, you'll know.
@verseddreams : what does the oil smell like; not much odor, grease, or pungent like gear oil??
FWIW
To decrease the chance of oil getting past the threads of the knuckle studs you can use a thread locker when installing the studs
but also you can seal the top/inside portion of the threaded stud holes which open into the knuckle cavity. However first you need to clean out the threaded holes extremely well and if reusing the studs, clean those threads also.
Example: while the knuckle is removed for a front axle job, I first super clean all the threads, run a cleaning tap (not a cutting tap) through the threaded holes, wash using a degreasing detergent and water followed by a solvent (carb/brake cleaner, Acetone, etc), repeat until the threaded holes are squeaky clean, also super clean the inside of the knuckle cavity.
Then after installing (new or squeaky clean) studs with thread locker push a small amount of your favorite sealant (FIPG, Permatex Ultra, Right stuff, ---) into the top of the (cleaned) threaded stud holes from inside the knuckle cavity, let that cure before putting it all back together.
All that cleaning is so the thread locker and the sealant will actually stick/seal.
FWIW/IME using the newer type knuckle studs with the star head (using a star E type socket) makes the process of replacing/tightening up the studs much easier..
(top photo stolen from a @scottryana post because I couldn't find mine)
Note the threaded stud holes are sealed from the inside of the knuckle cavity after installing the studs:
FWIW
To decrease the chance of oil getting past the threads of the knuckle studs you can use a thread locker when installing the studs
but also you can seal the top/inside portion of the threaded stud holes which open into the knuckle cavity. However first you need to clean out the threaded holes extremely well and if reusing the studs, clean those threads also.
Example: while the knuckle is removed for a front axle job, I first super clean all the threads, run a cleaning tap (not a cutting tap) through the threaded holes, wash using a degreasing detergent and water followed by a solvent (carb/brake cleaner, Acetone, etc), repeat until the threaded holes are squeaky clean, also super clean the inside of the knuckle cavity.
Then after installing (new or squeaky clean) studs with thread locker push a small amount of your favorite sealant (FIPG, Permatex Ultra, Right stuff, ---) into the top of the (cleaned) threaded stud holes from inside the knuckle cavity, let that cure before putting it all back together.
All that cleaning is so the thread locker and the sealant will actually stick/seal.
FWIW/IME using the newer type knuckle studs with the star head (using a star E type socket) makes the process of replacing/tightening up the studs much easier..
(top photo stolen from a @scottryana post because I couldn't find mine)
Note the threaded stud holes are sealed from the inside of the knuckle cavity after installing the studs:
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Could be grease separating . My money is early signs of an axle seal staring to leak . 3k is about the range they start seeping if you messed up a seal on the install or installed on an axles with a seal groove in it . I wouldn't worry about it until a drop hits the tire. In the past 6 or 7 months I have had 2 different cruisers develop seal leaks around 5k. Both had new axles and no damage to the seal. All where sumo kits. When pulled the seals were super flimsy almost like they were breaking down . The moly grease was RCV so and interaction with grease is ruled out . Only thing I can figure Sumo had a defective batch of seals ? I've installed hundreds of sumo kits and never had an issue.like this . I've stopped using sumo seals and put in marlin seals. 15k plus on both rigs leak free. Wish I knew for sure what happened .
