Differential Drain & Fill Plugs
Thread Starter
Melting Slicks
Joined: Jun 1999
Posts: 2,263
Likes: 48
From: NJ
Differential Drain & Fill Plugs
Routine maintenance...
Changed out GM Synthetic Axle fluid to Dexron LS last week.
Only had 11k miles on it...no probs with diff...fluid came out clean.
But I noticed a dark gray glob on the magnetic drain plug.
Anyone else notice this?
Also, no washer (no "axle fill" tag either...came without one from factory) on fill plug. OK to install without one?
Changed out GM Synthetic Axle fluid to Dexron LS last week.
Only had 11k miles on it...no probs with diff...fluid came out clean.
But I noticed a dark gray glob on the magnetic drain plug.
Anyone else notice this?
Also, no washer (no "axle fill" tag either...came without one from factory) on fill plug. OK to install without one?
Last edited by LIGHTNING; Jan 9, 2012 at 12:33 AM.
Safety Car
Joined: Aug 2002
Posts: 3,842
Likes: 230
From: SANTA CRUZ CA
Comprehensive 'how-to' with pics...... no mention of a "dark gray glob" on drain plug, nor a washer:
http://www.toquez06.com/diff.html
http://www.toquez06.com/diff.html
Tech Contributor
Joined: Jan 2007
Posts: 19,472
Likes: 1,171
From: Dyer, IN
Thread Starter
Melting Slicks
Joined: Jun 1999
Posts: 2,263
Likes: 48
From: NJ
Tech Contributor
Joined: May 2008
Posts: 3,100
Likes: 17
From: Somers, CT and Clermont, FL
St. Jude Donor '09-'10-'11-'12-'13-'14-'15-'16
Yep, it looks perfectly normal for a 1st time gear oil change at your mileage. 
I did a 1st time gear oil change on my Silverado recently, (also with about 10k miles on it) and I saw about the same amount of metal paste attracted to the soft magnet on the inside of the diff. cover.
BTW, you made a good choice for your new gear oil.
I did a 1st time gear oil change on my Silverado recently, (also with about 10k miles on it) and I saw about the same amount of metal paste attracted to the soft magnet on the inside of the diff. cover.
BTW, you made a good choice for your new gear oil.
