I have a 2000 4 x 4 F250 with 3.73 limited slip rear end and 39K miles. Lately I've seen oil around the pinion seal and decided to see how much fluid was in the rear end. Removed the fill plug on the side and was happy to see oil all the way to the top. Was not happy to see metal shavings, most of which were small, very fine, like dust but there were also a few, (5 - 6) that were larger. Some were 1/4 inch long by .010" in diameter. I'm concerned enough that I plan on pulling the cover to look further unless someone thinks this material is nothing to worry about - Harmless in other words. I grabbed the pinion and tried to shake it to see if pinion bearing is gone - it felt fine. Anybody have any ideas or thoughts on this subject - I am worried. Most of the material was attached to the fill plug which is magnetic.

 

It's probably just normal break in wear, at least it doesn't sound abnormal. I'd say go ahead and clean the mag plug and drive it a few hundred miles and recheck.

 

Cookie88 thanks for the reassurance - I will do that - I was concerned that there might be larger chunks lying on the bottom that the mag plug might not grab up. It's probably safe to assume if no more small pieces surface that theres not any large pieces to worry about.

 

I am currently having the pinion bearings and axle bearings replaced in the rearend in my 2003 F250 7.3 truck. ( 57000 miles ) I had started to notice a slight vibration coming from the rearend around 20-30mph. Dealership thought at first it was the front wheel bearings and replaced. No fixy! Then checked rear wheel bearings- all good. When they removed the cover on the pumpkin cover the oil was kinda grayish looking with the fines you are describing. They have since told me Ford in using a synthetic grease in the rearends and they have started to see a rise in rearend problems? Not sure if this change relates or not. I am replacing the synthetic with good "ol 80-90 lubricant.

 

KDatwyler, Thanks for the response - I have since removed my cover for a look see and other than my original complaint there were no additional shavings or even dust for that matter. I am still concerned with the fact my pinion seal is leaking altho not a lot (fluid level was not down) so I plan on changing that out. My oil (synthetic 75-140 wt) was a bright red like it should be. Don't forget to add posi additive to good ole 90wt if you have limited slip. I'm going to check with local Ford dealer about the oil too.

 

I'm not a big fan of friction modifiers, I prefer a limited slip that actually works. I always run without it.

 

PWRSTK2K,

I have a 2000 F350 crewcab dually with 82000 and the pinion seal is leaking on mine. I checked the fluid level and found the same as you. I added some 80-90w and closed her up. I see on hear that I should have added a friction modifier. Can someone give me the details on this?

Thanks Vinman

 

The fricition modifier additive is used in the oil to reduce the disc chatter in limited slip differentials when turning. Mostly just to remove the noise annoyance.