I recently bought 93 4runner with a procomp lift 33 bfg mud terrains. Knowing I'd have to put a little money into it, I didn't have mind it. It runs great.

At first I thought the pinion Seal was leaking but looking into I found a hairline crack where the rear axle mounts on the drivers side. Right along its leaking gear oil from it ever so slightly. Can I just weld it? Or would do some damage internally? If so what axles can I swap it with? 4x4 only? Or can I slap a 2wd one on there?

While inspecting the slight leak I found a sensor that wasn't connected. Can anyone tell me what it is? What does it do?

 

Ok and why didn't my pictures post.?

 

Pics of crack/leak and of disconnected sensor???

 

I tried posting it like 3 times. Let me try again

 

I tried finding out where it goes by the length of the cable but no luck.

 

Here's a highlighted pic.

 

Pretty sure that's the ABS sensor you're holding. If your third member has been swapped out it may or may not have a hole for it. If I were you, I'd pull those backing plates and axle shafts out and run a bead over that. Perhaps even clean it good and JB weld that. Hard to tell what I"m looking at based on the pic though.