Front End Klunk While In 4h Or 4l 97 Blazer

[Blueline]

Just trying to pinpoint the problem with my 4w drive. The 3 button system lights up and switches properly for all selections. The 4w drive works but will produce a fairly significant klunk at random - no particuar speed, rpm or shift.

If I drive the vehicle in reverse in either 4H or 4L it does not seem to produce the klunk at all.

One noticeable fault I've found is a slow but constant leak from the driver side axle seal. I topped up the fluid level but it had no real impact.

I was wondering if anyone had a good method for isolating the faulty component.

If the symptom is only showing up going forward and not in reverse can I rule out any bearing, cvjoint or axle parts?Could the gearing contact in the front diff be making slightly better engagement in reverse than when driving forward?

Appreciate any advice!

[wierdo124]

How many miles? Does it happen when turning? That sounds like a CV shaft to me.