Clunkity Clunk

Whenever I accelerate or brake, I get a single "clunk" its not that loud but I can feel it in the floor.. Almost as though something is smacking the bottom of the floor.. I looked under there a while ago and didn't see much so I gave up but its getting more and more frequent... Any ideas?

1990 S15 4.3L 4x4 Jimmy

U-joint maybe? Do you have a vibration with heavy acceleration?

I had that a few times, check your caliper bushings up front, the ones that the caliper bolts slide thru.

Whenever I accelerate or brake, I get a single "clunk" its not that loud but I can feel it in the floor.. Almost as though something is smacking the bottom of the floor.. I looked under there a while ago and didn't see much so I gave up but its getting more and more frequent... Any ideas?

1990 S15 4.3L 4x4 Jimmy


clunkity clunk,

my 2001 blazer did same thing...Ball joints needed replaced
and one wheel bearing...main cause ball joints, pitman arm....

clunkity clunk,

my 2001 blazer did same thing...Ball joints needed replaced
and one wheel bearing...main cause ball joints, pitman arm....


Mine went, CLUNKITY-BOOM!

Lift the tires off the ground and see if you can push the tire any abnormal ways . Check your engine mounts. watch the engine for movement while in gear while holding the brake .You got a few years on it now . I just replaced the ball joints on my 89.Rob

U-joint maybe? Do you have a vibration with heavy acceleration?

Actually yes I do.. but I thought it was my transmission because the vibration only happens when the truck is in OD and not in D.. well not so bad in D..

She's old, she has almost 400lk on her but she refuses to quit!

Whenever I accelerate or brake, I get a single "clunk" its not that loud but I can feel it in the floor.. Almost as though something is smacking the bottom of the floor.. I looked under there a while ago and didn't see much so I gave up but its getting more and more frequent... Any ideas?

1990 S15 4.3L 4x4 Jimmy
Its probably the torsion bar mounts if its a 4 wheele drive, They cost about 15 bucks and there easy to change

I have the same exact problem with my 92 blazer, mechanic thought it was the u-joint. Replaced the u-joint and i can still hear it.

Its probably the torsion bar mounts if its a 4 wheele drive, They cost about 15 bucks and there easy to change

Does removel of torsion bars require a special tool? Or can the back yard machanic circumvent this need?

A back yarder can do it . The dangerous part is releiving the pressure on the adjustment screw. My instructions showed using a tool similiar to a pully puller with two hooks . But it would not fit on one side because of other brackets in the way . I eventually used a floor jack that I removed the swivel pad from and installed a grade 8 bolt thru . then I jacked it up to the dimple in the torsion bar adjuster and releived it enough to remove the adjusting bolt and its block . I had the blazer on jack stands and lifted that side off the stands on the head of that one bolt on the jack . Carefull , lots of pressure . Rob