help solve axle and other problems for inexperienced mechanic!

[86sierra]

I have an 86 Sierra, 4" spring lift, 35" bfg at's and about 170,000 on the truck with stock 10 bolt axles.
I was driving the truck at least once every week or two, but let it set for 4 weeks, and have had problems since.
Driving to my fiancee's, truck began stuttering badly, parked it, her dad helped fix and found a rocker arm broken in half at the bolt.

Here are the problem's now-
1. oil or grease covering entire driver's side rear axle tube
2. truck seems to slow rapidly when coasting, like a brake dragging or rear axle binding
3. severe shimmy/hopping when slowing down to about 35 mph
4. loud "clunk" when shifting into drive/reverse (has done this for about a year though)

Sorry if the explanations are vague, but I think there is something wrong with the rear axle and am looking for the cheapest solution right now.

 

[Burt4x4]

Well the 35" tire on 10bolt axels is pushing the limits. So until you start taring into the housing and inspecting its tuff to say. I would remove the diff cover and look for metal pieces. I would try to move the drive shaft at the ujoint if it moved at all upndown side ot side then it's toast...

 

[dyeager535]

Check to see that the oil isn't coming out of the axle tube end nearest the wheel.

Could be related to the rapid slowing if the brake pads are contaminated with the gear oil.

Only 4 places for a rear axle to leak, (unless it's cracked) tube end, joint of tube to center section, yoke, or diff cover.

Is it gear oil or engine/tranny oil/fluid?

 

[garlicbreath]

Don't worry about the clunk when you put it in drive, every chevy I have ever owned did this, even with all new U-joints. As for the fluid leak, my suggestion is to pull the wheels and brakes and give everything a good hose down with brake cleaner, drive around a little while and pull everything again. Most of the time you will see where it's leaking. As for the truck "dragging" when you let off, I would jack it up, put jackstands under the rear end, disconnect the driveshaft and see if the wheels are hard to spin. It's prolly a bad axle bearing. Do some investigating on your own, then post back, alot of guys here know what they are talking about and like to help out the newbs.