Honestly ???

I had nothing else better to do.

 

Bought the truck with 40 000 miles. The first diff change was done at 80 000 miles. It was dirty brown. Mind you I never hauled anything
2 yrs ago changed it again. Silver, metallic in color. Maybe 5000 miles on that gear oil?
Looks like silver metallic greyish color is it's normal appearance after "normal driving" conditions.

 

There's solitaire.

 

I don't get a good feeling about this, so I hope someone has a more hopeful and different explanation... Here's my experience.

'01, now had for yrs, but then, began routine change of fluids, plugs, etc. Usual, v pretty eng oil. Ha.

Got to the differential, in time, and it had some particles. This meant axle seals, and all seals replacement was indicated. Bearings too.

While I was happy to have to do this, I found an axle had been replaced, and IT was seriously degrading. Inside the rolled-tube, up high, is the roll-junction, and it was full of silver metal paste. It took me 2hrs a day for a week to get fully clean. A shop has a pressure washer station for this work.

Seals, bearings, one axle, crush washer, yellow paint, correct RTV, (& for me, a drain to install in the cover.) Nuts, bolts, & washers to make the spring-washer compression tool, as mine has anti-lock, (Limited Slip,) being a 4x4.

 

Yea, but the axle is what goes first. It wears out underneath the bearing on the driver side. Bearing is usually fine wedged into housing. First you'll notice rumbling sound, like you have stones for bearings on that side. The seal fails shortly after, you notice that one day on the inside of the rear tire. Then you need to do something about it. If you keep up with gear oil changes, it doesn't usually happen until your right around 225,000 miles.

 

I've only ever done a few diffs but I've never seen silver fluid come out. I can't imagine how much wear there must be to turn all that oil silver.

 

Ya. What's up with that ?
silver grey color ? fluid was changed twice in the last 2 years !
this fluid has 3000 km's on it and it's grey ?

Time for rear diff fluid change !!!!

 

Change is good, but may I emphasize, very careful examination is due... Worst case, you learn that a change is a waste of oil. 🤞 BUT, once done, removal of a worry when in a previously owned vehicle. (Old unknown fluids concern me.)

My purpose in adding a drain could be for easier, more often changes. But, I cannot put such a drain in the cover low enough to allow a FULL drain... and I hesitate to add one the the bottom of the casing. It weakens it a tad. And the drain plug could be hit by rocks.

So a dif cover drain, to me, is mainly to drop a cpl-few ounces after a drive, every couple years for examination. I feel it's stupid extra work to re-gasket or clean and RTV, for any oil change, including trannys. It dissuades one from being timely and makes a easy pleasant task into a bit of messy hell, unnecessarily. First time that happens, a drain gets added. (Although I also get to add a magnetic plug, making two, now.)

To me this means exam in a 3 oz Anchor Hocking graduated cylinder, (Safeway,) but a small jar works. And IF any debris exists, then a white coffee filter. (You know, I need to paint a small magnet, gloss white, for use in the jar or filter paper.)

 

It's silver metallic colored oil, it's very likely not a waste in this case. If I do this job on my own...
I wanna make sure it's done right.
I'm not forking out $130 in labor for this.
Shop will easily charge 1 hour labor.

Should take about an hour ?

Gasket surface of rear diff cover should be super clean.
That's the main concern.

 

I don't know....she might consider that harassment with flux core lol. It's possible though.