Leaking Front Differential, Driver's Side

[burnettw]

My 96 Yukon SLT w/5.7, 4WD, 125,000 Miles has a leaking front differential (3.42) on the driver's side. It is also very loose (I can wobble it with my hand) where the output shaft exits the diff housing. I don't think the wobble is normal and will need more than a new seal to repair the problem.

 

Also, when driving about 70MPH I get a vibration that feels like an out-of-balance front tire but the tires are fine. Could the wobbly axle be the cause of the vibration?

 

Can the shaft be pulled and the necessary repair parts be replaced without dropping the the diff and if I have to drop it what all should be replaced; seals, bearings, etc.?. What would a rebuild kit cost? It looks like a fairly straight forward job... any gotcha's?

 

I would also rather use synthetic gear oil but I've read that synthetic can ruin seals and gaskets and is not recommended for the front diff. Any thoughts on this?

 

Thanks for the input...

[oldschool327]

Yoke and seal can be replaced without any problems. Bearing yeah looking at some work. Woble could be from yoke and synthetics do not cause seal failure!

[jro909]

front diffs don't call for synthetic oil i thought they use good old grease...regardless synthetics can be used and they do not harm seals

[oldschool327]

Grease in a differential??? Maybe your thinking at the wheel bearings but not in any differential, always oil.

[jro909]

Grease in a differential??? Maybe your thinking at the wheel bearings but not in any differential, always oil.

 

 

i ment none synthetic lube