Front End Looseness / Thunk

[RWWinslow]

Been noticing a gradual increase in a 'thunking sound' from the front end while turning the wheel or driving over a rough road. For the record, this frame has almost 400,000 miles on it. Drag link, tie rod, etc. are all relatively new (< 10,000 miles). Jacking up the front axle and checking freedom of movement shows that the ball joints are also still tight and they have been religiously greased. Front springs and bushings are also relatively new with polyurethane bushings. Since this is a 4WD the front axle u-joints have been changed to greased units and are relatively new. Steering box is 3 years old and still tight.



Is there a history of some of the rivets fatiguing / working loose and if so which ones? May need to do a ball joint replace anyways but would like to catch the rivets if they are bad / suspect.



Thanks for your help and comments!

 

[TKingsbury]

My front clunks a bit when turning, but it's because my front shackle bolts aren't tight enough. When I put in my front springs I will put better lock nuts on, but until then I just tighten them once in a while. You might check all of the bolts in the trans crossmember and pretty much make sure everything is tight under the truck. Although I have noticed that loose frame bolts usually creak, not pop or clunk.

Travis. .

 

[PPeters]

Check your steering gearbox mount to the frame for cracks.



Pat

 

[PORPRES]

Might want to check the Kingpins on the front axle. The nylon cones do wear out. I would also check the wheel bearings and spindles.

 

[RWWinslow]

How difficult are the king pin nylon cones to replace?



Anyone have a part number?



Does the steering gear box have to be removed to check for the cracks? (It was last off two years ago when it was replaced. )



THANS!

 

[PPeters]

Tried to search the archives for the thread that I did on my front end rebuild, looks like it's gone. Had everything you want to know in it and more (or less).



King pin bushings are not a big deal to check, disconnect drag link, pull the caps. Spring and bushing are right there.



I think I would side with PORPRES and check everything, esp. with your mileage. Randy's Ring and Pinion sold a complete kit for the kingpins, along with the bearings you would need (inner, outer, torrington, etc. ). Price was reasonable, I think I got away for less than $200 american for EVERYTHING to rebuild the front end. The only bearings I didn't change were in the diff where the axle shafts entered.



Cracks in the mount plate may be visible without dismounting, but if your truck is like my old 92, vehicle drool will obscure them. Best to pull the box and examine the plate. Part was available from the dealer last spring, for about $15.



Take my advice with a grain of salt, since I'm really only allowed in this forum with my hat on backwards...



Pat

 

[RWWinslow]

The only thing that hasn't been rebuilt on the front end is the kingpin nylon cones / spring - so that is the most likely culprit - appreciate the assistance. Anyone with a part number - would be a great help! Living in the backcountry of Wyoming a lot of stuff is done over the phone and via internet so part numbers are always a big help.



THANKS AGAIN!!