I think I f'd up guys
 

Well, to make a long story short I had a rear end leak.....changed the hole rear end cover due to the fact it was bent....I was filling up the rear end til it spilled out..which is a good sign its full. Ok now that it's full i didn't know that Friction Modifier was supposed to go in too.
My question is will it mess my rear end up immediately, or do I really need that stuff since im gonna change the gears anyway in about 2-3 months? Can I drive it for a couple of miles and get some of the fluid drained out and put some friction modifier in it?

what kind of gear oil did you use?

Some gear oil has a friction modifier included, most don't. I wouldn't run the car without friction modifier. It won't bother your gears, but it could damage your clutch pack. Reference the link below:

http://www.performanceoiltechnology....ch_chatter.htm

If you used mobil 1 then you need the friction modifier, if you used royal purple then you don't.

the friction modifier is only a few ounces (I thought is was only like 5-7oz) for the Ford bottle. Take the plug back out and get a small diameter hose to stick in there and siphon some of the gear oil out. If you get a transfer pump, this is pretty harmless. You can get a manual pump transfer pump for under $20 and it has plenty of uses.

only need 4oz of friction mod...just suck a little fluid out and then add it