Left front wheel well. Piece of wire and vacuum tube (?) hanging down that should be plugged up higher. Tube is plugged off on end.

Any idea what it is?

2002 GMC Sierra 2500hd crew cab duramax 4wd

That looks like the front diff vent. GM used those 4 wire flat plugs for O2 sensors on the gas trucks, but diesels don't have O2 sensors so that isn't it. I can probably check my dad's dmax tomorrow if someone doesn't have a better idea.

Not abnormal to have useless plugs on a semi-universal wiring harness that is made for a truck that has all the options

I cheated and looked in AllData. That's plug C150 - "transfer case harness to axle jumper harness"

Did you pull your front diff?

Replacing axle seals. Right hand is a PITA

Nice. I've gotta do mine too, but plan to send it off for a complete rebuild. I have an obnoxious whine that occurs about 30+mph.

Greenchiles said:

---

Nice. I've gotta do mine too, but plan to send it off for a complete rebuild. I have an obnoxious whine that occurs about 30+mph.

---

Sure that's not the passenger?



Mine is working fine, just slinging oil all over the place. The left two mounting bolts for the axle are not accessible with an air wrench, look like a pain to remove.

The left seal is easy, the right involves removing a tube that has a mount that will not move out of the way. So you have to loosen everything, and pry it out to remove.

The challenge is reinstalling without dropping parts, and leaving stuff loose enough to pry into place, etc.

Not 100%. My guess is it's the pinion bearing since I feel a slight vibration in my feet.

Greenchiles said:

---

Not 100%. My guess is it's the pinion bearing since I feel a slight vibration in my feet.

---

I felt a vibration in my feet once and traced it to…the radio. Certain bass notes vibrated the floor under my