diff. fluid change question

I'm going to be changing my differential fluids this weekend on my 2000 rodeo ls v6 4wd. I am going to get a fluid pump and suck out the old fluid and put in the new. My question is about the fill screws in the front and back differentials. Do they need washers, o-rings, teflon tape or nothing at all? I don't want to take out the fill plugs and then hitch a ride to the store to buy something for it. Any other tips would be greatly appreciatied.

I am also going to drain my engine coolant and just refill. I assume the easiest way is just unscrew the drain plug under the rad on the driver side.

John

I just did the diffs in my 99 v6 4wd a few weeks ago. Not bad at all, takes a little time, mostly due to the slow fluid flow. The front diff has a drain plug.
http://files.automotiveforums.com/gallery/watermark.php?file=/503/163328Picture_11.jpg
It will look something like this. It is the lowest bolt and it looks a little different from the others. This drain bolt makes the front the easier of the two, however, the rear is easier to fill. You may want to remove the spare tire if it is mounted under the vehicle. It gives you more room to work.

One thing I recommend is to buy two pumps. One to remove fluid and one to add fluid. They are so cheap, it makes sense. I threw the pumps out when I was done. Only thing I would have done different is to remove the rear diff cover to inspect the diff as well as to get 100% of the fluid out and wipe it down. Using the pump, it is impossible to remove all the fluid and get and sediment out of the bottom. I may do this in the spring.

As for your questions, there is nothing needed on the check/fill plugs. Also, while you are under there, check the diff breathers. If the check plugs hiss or "shoot" off, they are clogged. My rear was clogged so I popped out the breather and freed it up. Check the fluid level several days later. Mine was over-filled, but the excess just ran out and all is well.

Marc

I would recommend pulling the cover for the rear diff to drain it. I just did mine last week. It had the original oil in it (89k miles) and was really nasty. The rear cover was coated with thick black stuff to the oil level line. I had some trouble getting the original silicone gasket stuff to break loose. Now I have a regular gasket coated with anti seize so everything will come apart easy next time. I also replaced the weak stock rear cover ,that will crack if it even see's a rock, with a steel one. Removing it makes it easy to inspect the parts and do a better job of cleaning. You will have to take the lateral rod loose to get the cover off.

http://isuzufaq.ibctech.ca/#faq47

Agreed, If you're going to do the rear, do it right. There will be gunk on the bottom of the differential that you can clean out that a pump won't get.