Well guess who's clunk is gone? yup. I am calling this problem solved, for me anyway. Not exactly sure what did it but its gone.
So I spent about 5 hours on the front end of this truck again yesterday, I figured, this is it, either this fixes it or I am done with this MF'er. I went slow, methodically, looked at everything, double and triple checked every nut and bolt. It is 100% fixed, quiet like a new Platinum or King Ranch. I am satisfied. Love the truck.
This is what i did.
-New upper control arms, standard Moog brand.
-New upper Spring hats, Moog stuff.
-Tightened the lower shock bolt in full droop with a large screwdriver jammed in below and pushing up on the shock bottom eyelet.
450 lb ft +
-Pulled the driveshaft and greased the yoke.
So it was one of those things, which one I am unsure, but i have a few ideas.
Shocks...That bottom shock bolt up design sucks, I believe the LCA is shrouded on the bottom so the eyelet doesnt get bashed offroading, but in my opinion there is not enough clearance below the eyelet to compensate for bushing wear, bushing flex, and tolerance stack ups. Thats the reason I tightened the lower bolt in droop plus forcing the eyelet up to maximize the clearance. Even doing it this way i could barely fit a slice of cardboard between the shock and the LCA. Its not right, it is designed to have 5-6mm in there, it doesnt.
Spring hats... People probably reuse the old ones when doing a shock rebuild, I did, but do you know how it is designed? it is a UFO shaped metal piece encapsulated in rubber that cushions the jounce. If that metal piece separates from the rubber internally i think it could make a thump, especially in cold weather when the rubber is harder. They are like 45 bucks, just replace em.
UCA... although my uppers seemed fine, i was a bit leery about them. bushings seemed ok but had noticeably more flex when cycled by hand in position disconnected from the spindle than the new ones, much tighter. Also the ball joint was easy to move but exhibited no play when messing with it. But, maybe under the large forces when going down the road maybe it had a little play? dont know.
Driveshaft yoke... I had no takeoff thump which is the symptom of a dry yoke, but while i was doing things, thought id visit it. it had some lube but not a ton, this thing moves alot in and out going down the road. i packed it full of wheel bearing grease. if nothing else i feel good about checking it.
Well I am done with this, I hope my many many hours on this truck help someone solve their noise. Now my wife and my neighbors can stop wondering why im always wrenching on this thing.
