Differential fluid changes

From: David Gersic (info@zaccaria-pinball.com)
Date: Wed Apr 11 2007 - 11:48:54 EDT


My '01 is about to turn 100K miles (bought about a year ago at 96K), and I
have no idea when, or if, any of the fluids had ever been changed, so I spent
yesterday in the garage draining and replacing the oil in the engine, trans,
transfer case, and both diffs. I hadn't done diffs before. Back one was
pretty easy. Front one was a bit of a pain due to lack of clearance around
the steering, but I got everything buttoned up again ok.

On the ring gears, I compared the wear pattern to pictures, and it looks good
to me, but wanted to see if there was anything here to be concerned about. Do
these look good:
        http://www.zaccaria-pinball.com/temp/rear-diff-wear-1.jpg
        http://www.zaccaria-pinball.com/temp/rear-diff-wear-2.jpg
        http://www.zaccaria-pinball.com/temp/front-diff-wear.jpg

Also, on the rear diff (8.25" 3.55 Trac-Loc), I noticed this:
        http://www.zaccaria-pinball.com/temp/rear-diff-q.jpg
imperfection in the face of one gear tooth. Is that going to be a problem, or
is it ok?

In case it's useful information for somebody for the future, the transfer case
drain and fill plugs need a 10mm Allen wrench to remove and install, and the
transmission drain and fill plugs need a 17mm Allen wrench. I got lucky and
found a 17mm Allen at my local hardware store. I have no idea why they have
those in stock.

Refillling the rear diff was pretty easy, using one of those oil change valve
things with about a foot of clear plastic tubing on them that screws on to
the top of an oil bottle. I used that on the transfer case, too. Refilling
the trans and the front diff were a bit harder. I ended up using the same
valve thing, but bought a 3 foot section of tubing for it. I threaded this
down from the top side of the engine, and in to the fill hole. To get the
first quart in (especially for the 80W90 gear lube), I opened the valve, then
used a knife to punch a hole in the bottom of the bottle to allow the air in
so it would drain. For the second quart, I used the knife to cut the bottom
off the bottle, turning it in to a really long funnel and just poured the
stuff in from the top. Worked pretty well, since both are of the "fill until
it overflows" type, I just put a pan underneath and kept pouring until I
could see it dripping.

I saved samples of the fluids to send off to Blackstone. I'm curious to see
what they have to say about these.



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