Doing the brakes and noticed a lot of crud inside the right rear rotor. Oil looks to be seeping from the area where the flange goes into the hub - this leads me to believe the hub seal is the culprit. The other 3 hubs are clean and dry.

Should I replace both rear hubs, or only the one that's leaking. Leaning towards only fixing what seems to be broke.

Advice?

Thanks in advance.

 

As a field technician on equipment... do both sides. As a DIY guy for myself... daily driver or wife's vehicle then do both. As a third vehicle, do the side that's leaking. Check axle for wear around sealing surface. Check axle vent. Use a hammer activated impact driver for the philips head stuff.

 

Slap a new o-ring on the hub and see what happens.

 

I bought 2 hubs when my Right/Rear was leaking, same as yours. Replaced the bad one but got distracted with other projects and never did the left side. It's been 2 years.

 

The genuine wheel bearings coming on the truck are well made & hearty. I would service the seal itself - the oil seal in rear is just a large O-ring & I would order a few at same time. they are cheap. This way you have one for other side and additional incase you reinstall and chaffe it going in.. ( I can say, a time or two I’ve reinstalled and knicked the seal pressing in hub & 2 days later notice that weep again. Frustrating but very achievable to get it right)

this way when you pull your wheel bearing, it will be separated from your drive axle & you can spin in your hand & feel how smooth it is. Essentially confirming Your suspicion the seal is your culprit & not your hub.. it Should spin silky smooth - if so; no reason at all to swap in my opinion. I have put many many highway and Offroad miles on my original hubs & Swapped for used OEM hubs Over new & run for 10’s of thousands of miles & counting.

If high miles - I was taught a trick to remove abs sensor & drop a tsp or so of lucas hub oil in there. Its like honey for your hub. (careful of the O-ring & ensure senser remains/wiped clean as reinstall)

 

Based on where its leaking from (where the flange enters the hub), I suspect the hub seal - not the O-ring. Can the hub seal be replaced?

 

You have grease in your hub- not oil. Not sure what you could looking at leaking back there other then gear oil from diff . Take a photo perhaps.

 

You're right. If the O-ring did fail, it would leak from the same spot. I was thinking an O-ring leak would only manifest itself by leaking at the hub to axle housing joint.

 

Clean the vent tube. Probably plugged and causing leak.

 

Ended up replacing the hub. Cleaned up a bit too, and finishing the brakes...