Tips for changing diff fluid?

[rbeech]

I only have 1800mi on my truck, but in an effort to protect the fragile little rear end, have decided to change the fluid to Mobil1. Getting ready for my second tow trip of 375mi each way through the heat and up some grades. My first tow was about 200mi round trip. bestatchess recommended fluid change around 3k, but I figure a liitle sooner will be better than later.

Since I have never changed diff fluid before, I am curious if there is anything more than draining and refilling? Any seals or washers that need replacing? Any special tools? I would hate to get the fluid drained and realize I needed a special part or something? Thanks and sorry for the silly question.

[Mr. B]

It's as simple as you think....drain and fill.....there is a strange little procedure where after you refill it, drive it around a little, making sure to turn sharply to the left and right and then re-topping off.....but I don't remember where I read or heard that.

[electricjohn]

A short piece of clear ty-gon(sp?) tubing on the end of the lube oil bottle's spout makes the task go alot faster. 3/8 tubing is what you need.

[bestatchess]

A ratchet handle w/o socket turns the plugs. Permatex high temperature or high performance thread sealant (don't use thread lock) for the drain & fill plugs. I think torque is 20-25 lbs. Park truck on level ground. You can buy a pump to pump the gear oil, but to me mashing the bottles is just as easy. It comes out easier if the fluid is warm (truck recently driven) but be careful not to burn yourself or drop the plug into the drain pan. The magnetic drain plug will have swarf. Observe how much, photo if so inclined & clean before putting back. I like to clean the plugs & apply fresh thread sealant, although some people just put them back w/o new sealant, relying on old sealant to seal. Be careful not to cross thread, strip over-tighten. Observe thread depth seating of plugs prior to removal. You could even count rotations of the plug on the way out so you have an idea of how tight to put them back.

[rbeech]

Thanks for the tips guys. I haven't bought the fluid yet but I just removed the fill plug to check level. I thought I read that the fluid stinks, so I wasn't surprised at that. I used my pinky to check and noticed that the fluid had a gray color to it. Fluid was not warm, I only pulled the truck into the garage to be on level ground. I don't figure new fluid should be that dark. Now I really want to change it out.