blazerdup

Let me say that I haven't messed with axles much. But when I had the passenger side axle out the other day to replace the axle seal, I noticed a lot of gunk build up in the housing and on the axle. Is this something I should be concerned about right now? Is there an easy way to flush it, clean it? Would this be the reason for some noise coming from that area while driving?

Need some help to determine how serious this is and what my options are.

001mustang

Check fluid for burnt smell, metal particles and opacity.

After driving on highway for about an hour verify third member pumpkin temp does not exceed 190F w/ IR gun. Mine runs about 130F to 150F.

I would not flush but wouldn't hurt to change fluid.

Check pinion seal for leaks and check pinion for up and down play.

Rear end can make noise for years w/o issue. If metal particles are generated or temps are high then time to rebuild. May also rebuild for piece of mind or if noise bothers you.

blazerdup

Cool thanks. I know it was low on fluid because the rear seal leaked into the brake drum. I have since fixed the seal and re-filled the fluid. Is there any reason for concern with the build up of gunk?

001mustang

I don't think gunk will cause issue.

I like to check axle bearing temp w/ fingers following highway runs.

blazerdup

ok good, I can focus on other issues for now. thanks,

rtintwo

The only thing i would add to what has been said is that if the gunk is white then it needs to be cleaned out. White means it has got water in the rear end.

JMD

Sometimes, dislodging sludge etc. is BAD...

blazerdup

Fortunately there is no white. And yes I agree about dislodging the sludge. I chose to just leave it for now.

2tonterror

The sludge/gunk buildup is from the rear end gear lube coking. When the axle bearing gets too hot, it causes the oil the solidify(coking). More than likely, the bearing/axle shaft was overheating due to the seal leak. Was the beaing or the axle shaft discolored( blueish tint)? I would change the bearing to be on the safe side.

blazerdup

I didn't noticed any discoloration on the axle shaft or bearing. It looked normal except for the build up, which I attribute to the leaking and drying out from the heat like you said. I will continue to monitor it of course am considering swapping it out in the future for a 5 lug rear end.