Hi everyone. I have a problem here that has been occurring for a while and both me and my preferred shop are at a loss to find out what it is, so I would like to ask if anyone on the forum has had this before. During turns (especially after the car has been sitting for a while) I feel and hear a loud knock at my feet coming from the front end. It usually happens when the wheels are turned right whether I am backing up or turning right. I had the entire front end checked out and except for a ball joint with some play (upper right again. This one lasted less than a year. Had it replaced. Probably from hitting a raised lip of a driveway to prevent an accident.), there was nothing visible wrong. Everything was replaced within the past 1-3 years: Ball joints (All except one less than 1.5 years old), wheel bearings (less than 1 year), idler arm (3 years), pitman arm (1 year), sway bar end link bushings (last week), CV Axles (2009 and 2010). It makes the noise whether the front axle is locked or not (in 2HI), so I can rule out the front differential. The fluids are good (level and condition) on everything. What could this be? It is annoying and I am concerned.

 

Do you have a metal skid plate under the engine? My '96 Sonoma has one of these, and it pops whenever the frame flexes. Started doing that years ago when one of the stock bolts stripped and I replaced it with whatever I could find in my garage. Makes those noises under the same circumstances as what you describe.

 

Negative. Only skid plate is the plastic one that is over the oil filter.

 

Have you checked the body mounts?
If the frame is flexing and your mounts are loose....maybe???
just a thought

 

If you don't mind me asking, just how do I check them?

I didn't notice any obvious things like cracks, but I had to scrape off loose rubberized paint since it was chipping and there was new rust on the frame. I hit it with black primer. I try to keep a coat of paint on the frame, especially for summers (for mud) and winters (for salt/snow).

 

The mounting points where the body meets the frame....check if your rubber biscuit is intact or maybe is rusting...mine makes a noise under my left foot sometimes ....i never found any mech or suspension issues...it justs shifts when it flexes.
like i said....i maybe grabbing at straws but if your susp checks out.

 

Its torsion bar mounts. Had the same issue and my blazer,a friends,and ive helped alot of people on here with it. Im 99.999999999999999999 1/2% sure its the torsion bar mounts. they are like 20 bucks each,you need 2. follow the torsion bars to the torsion frame behind the transfer case and you'll see the mounts on each side that are bolted to chassis,and torsion member.

 

^^^^^^
that would make sense.
i better check mine out.

 

Warthogdriver: I didn't see any rubber biscuits missing, but I will check again. Would it help to try to tighten the bolts?

Chris015: How are those replaced? What is wrong with them that they make noise? That requires alot of work, doesn't it? Am I better off forgetting about it? Could the bolts just be loose or could the mounts be busted?

 

heres a video of my broken mount. Epic LQ video ftw.

Broken torsion bar mount on 91 s10 blazer - YouTube




The mounts seperate from each other.....you have a metal plate and a chunk of rubber with a stud in it. the stud and chunk of rubber bolts to the torsion crossmember that holds the torsion bars. when you turn,or go over bumps the crossmember will flop up and down on the side that has the broken mount. Here is a few pictures on the mounts.


By chris015 at 2012-03-10

By chris015 at 2012-03-10



you simply remove the nut on top,and the 2 bolts on bottom and remove/replace. Its easier to use a floorjack on the lip of the crossmember to lift it off of the mount AFTER you remove the top nut.


edit : also to throw in, if you decide to do both, the passengers side requires the "improved" version that has 3 bolts instead of a nut and stud. you cant get the member high enough to slide the new one in due to the exhaust. the stud bumps the member since its not high enough. Moog makes the improved version. the driver side you can use any torsion mount as it has plenty of room.