First Post .... Help on a vibration

[DuallyDave]

FF axle?

 

[98_k1500]

Does it have a semi-floating (sf) or full floating (ff) rear axle? Either way, you could check runout with the tire barely off the ground. Lay a large block right beside the tire (ALMOST touching it) spin the wheel and see what the gap between the tire and block does.

 

[thz71]

Im not sure what that composite shaft cover is made of, but i know i have seen more than one of them "rotted" and slung off.

Idk what it is either but it's not carbon fiber lol every driveshaft would be worth more than the truck

 

[DuallyDave]

98_k1500 .. Thats a great idea !
i know what im doing over the weekend... lol

It's a 14 bolt Limited slip with 373 gear.
i thought at one point it might be the pinion. But it seems good.

 

[98_k1500]

That 14 bolt can be either a sf of a ff. 9.5" ring gear is a sf, 10.5" is a ff. On your rear axle, does it have a axle that bolts in with 8 bolts under your center cap? Or does it just have a normal looking axle flange and brake drum?

You must be registered for see images attach

ff axle

You must be registered for see images

sf axle

You must be registered for see images

Difference in pan gasket patterns between the two. Their ring gear measurements are off .25"

 

[DuallyDave]

Its a FF axle...

 

[98_k1500]

You can check those rear wheel bearings with a pry bar like checking your ball joints on the front. Could be a front wheel bearing going also. I would check all 4 wheels for up and down slack. (large pry bar with the wheel 1" off the ground is the easiest method) Try swerving between lanes (safely lol) when it is making the noise. See if it changes when turning left or right. (off ramps on a highway work nice for this)

 

[DuallyDave]

UPDATE...
So I did a rear brake job. Decided to relace everything. Appearently the vibration has been from the Brake Drums. There was a little bit of rust that had flaked off the outer edge. I didn't think that it was that big of deal. but these drums are so big that they are balanced.

Thanks gys for all your help!