Loud bang in front end?

Hey guys,
I've had my 01 Tacoma for about two months now. Ever since I got it, I noticed a small oil drip. Two weeks ago when I got the oil changed they told me it was leaking from the front differential axle seal. A few days ago as I started pulling forward, I heard a very loud bang from the front end, and it felt almost like it was slipping or maybe binding up. I haven't driven it since other than to show my dad the noise. It only does it in 2WD, 4WD is fine. It also only does it in first gear. Any ideas what could be wrong?
Thanks!
Eric

 

Forgot to mention, before the first bang, the oil drip was very small. After, it dripped just about as much the next day as it had a first two months.

 

Usually a loud bang from a differential means you oil starved it.


I did a diff oil change in my rear axle and didn't measure how much I put it..thought I filled it till it was dripping out..but skipped my mind to even check
Short not a substantial amount but 1000 miles later and my differential went KABANG

Housing was hot as hell when it happened also

 

Thanks for the replies.
Undefined, did you end up having to replace the whole differential? What was the cost on that?

 

It was more cost effective to buy an entire axle.
I have a 5 lug truck, and I picked up an axle with 90k on it for $150 from a fella a couple hours away...a Taco buddy (fellow member here and on CT) drove me to pick it up in his slammed Taco


You'd be better off replacing just the front diff..instead of entire housing and assembly.


Labor was free for me.
$20.25 for fluid
$5.46 for pack of Reds
$2.10 for a 40oz

Total cost:

$177.81

 

Took it in today. Turns out it's actually the rear differential. Still waiting to hear how much the damage is going to be.