I'm in the middle of changing front and rear differential fluids, transfer case fluid, and tranny fluid. I have read through the thread in the DIY area, and I wanted to make sure I have the correct vent cap on the front diff. It was mentioned that if you are changing from regular to synthetic fluid in the front diff, to change to the newer "white" vent cap. My truck is an '03 model, and it appears to already have the white cap. I just wanted to make sure I was looking at the right thing. I have attached a picture. Is this the white vent cap (see arrow in picture)?

6801

Yes!

Thanks for the help.

Doh! I thought the front diff 'vent cap' was the cap on the top of the diff vent hose in the engine compartment. Look at the picture above - you will see the black vent hose going up into the engine compartment. On the end of that hose is a small breather which is black.

I take it the diff vent cap everyone is always talking about is the one shown in the picture above screwed into the transfer case and not the small black one at the end of the vent hose. Correct?

Right. I had an '01 model and had to change from the black to the white model, when I switched to synthetic fluid.

I think GM's terminology for the part is "connector", but I still call it a vent cap too...

What is the GM part # for the white vent cap ? . I need to change my diff fluid in both the front and rear. Thought if I was going to put in synthic in the front diff I had better have the white vent.
Mark

The part number is 12479390.

Well...since mine already has the white cap...I guess I won't be needing the one I bought...

If anyone in Southern California needs one let me know. I'll give you mine for $10. Cost me about $23 from gmpartsdirect. Work in Santa Ana area, live in Corona area. No mail.