Squeaking front end AND leaking front differential

Hey Guys! I haven't posted in a while but I have a problem with my truck.

I've been noticing a terrible squeaking coming from the front end of my 2002 Z-71 while driving. It's been like this for several months. Just today I noticed that there is fluid leaking from the front differential on the driver's side. I noticed it dripping under the car and upon closer inspection noticed that it was flung all around the driver's side of the front diff. I believe the squeaking and leaking are related.



The black dots are where the fluid was dripping.
The red lines show where the fluid was being flung.
The blue line is where the fluid seems to be coming from.

Anyway to fix this? Any suggestions are appreciated.

Thanks!

It looks rather thin for gear oil to me, what does not smell like. I think gear oil smells bad,

It's oily but doesn't smell like oil. I can't really describe it any better then that. It does smell bad though.

Check your power steering fluid level just in case its that.

This is your axle seal. I have replaced both my drivers (easier to do) and my passenger side at a later date. Mine looked exactly like yours. Plenty of posts here and is a DIY job. Its about a $15 part and another 20 or so to replace the fluid.

I'll check the ps fluid tonight and get back to you.

butterfingarz said:

This is your axle seal. I have replaced both my drivers (easier to do) and my passenger side at a later date. Mine looked exactly like yours. Plenty of posts here and is a DIY job. Its about a $15 part and another 20 or so to replace the fluid.

Click to expand...

I was thinking their had to be a seal in there. Glad to hear it's a DIY job! Did you notice a constant squeaking from the front end while driving before you replaced yours? Also if you happen to have a link to a thread with more info would you mind posting it, if not I'll do a search tonight after work.

Thanks!!

I did not notice a constant squeaking on mine. I do have a low noise sort of like when 4x4 is engaged and turning sharp from the front that is either the CV joints or hub assembly that I have not gotten around to.

You'll have to do the search since it takes forever to do any searching on this forum. I posted it in if that helps.

I found the tech article, I'll go ahead and link it here in case anyone else needs it too. http://www.chevyavalanchefanclub.com/cafcna/index.php/topic,44248.0.html
It looks pretty involved but I'll have to give it a try. Thanks for the help!

Those instructions are bit overwhelming.

It fairly simple though. All can be done without removing any wheels or lifting.

Drain diff
mark CV spline in relationship to inner drive shaft that comes out of the diff just to be safe
Remove six bolts
Move CV drive shaft down out of the way
Use a brass drift or a hammer against a soft piece of wood to tap the inner drive shaft out
    (Mine was stubborn and felt like I was going to break it)
Use large screwdriver gently to wedge the seal out
Clean surface
Find something that is the right diameter as the new seal and gentle seat it( I think i used a 32mm socket)
Reverse the last couple of steps
Refill diff with new fluid. (You should just be able to touch the fluid with the end of your finger in the bottom of the fill hole)
Pat yourself on the back for saving a lot of money


One thing to note. This is a very common problem. You may considered replacing the passengers side at the same time since its only bound to eventually happen on that side as well.

Thanks for the help butterfingerz! It was actually a very easy job. I replaced the seal and refilled the diff with Lucas gear oil and the leaking is gone!

However the squealing is still there. Anyone have ideas on this? It is a constant squealing from the front end while driving. It's loud enough that it can be heard with the windows up.

Thanks guys!

Glad I could help.

As far as the constant squeaking... If its rotational then I would check out your front hub assembly. Lots of problems with these as well. I think the test is jack the front end with the wheels still on and try to shake the wheel (both vertically and horizontally) and if theres movement you should have it checked out further. Even though this is essentially the same test for tie rods

on a side note, is the bolt to the northwest of the blue line the fill plug for the front diff?

If so, is the drain plug just located on the bottom of the diff, covered by the skid plate?

bucklwi1 said:

on a side note, is the bolt to the northwest of the blue line the fill plug for the front diff?

If so, is the drain plug just located on the bottom of the diff, covered by the skid plate?

Click to expand...

Yup you got it.