I have a noise in the rear of my coupe that I can't hear but my wife swears she can. I put it on ramps to visually inspect everything. I noticed the rear leaf has an adjustment bolt thru each side. Should there be a locknut on that adjustment bolt? Would that adjustment be used for lowering/raising and leveling? Thank you for any replys.
Steve

 

Hi Steve

No locknut is required. It comes from the factory just like you see it on your car.

And yes - those are the so-called "lowering bolts". They are used to adjust the ride height of the car.

BTW, have you owned the car since it was new?

If some previous owner put in some aftermarket lowering bolts, it's pretty common for the plastic pad on the head of the bolt to wear off or break loose. The head of the bolt rests on a web on the lower control arm, and if the plastic breaks off or wears away you'll have metal-to-metal contact and could have noise during normal suspension movement.

Bob

 

Thank you Bob. It just didn't look right at first glance to not have a locknut. There appears to be more visible thread showing on one side than the other. The car sits level so I guess there isn't a problem. Now back to the noise that only my wife can hear.

 

I was adding to my post while you responded.

Take a look at the BTW I added which has to do with possible noise.

Bob

 

I Just checked and the drivers side is adjusted out so that more threads are showing than the passenger side. The plastic pad that you are refering to on my drivers side looks like it's shifted. It looks like a stack of maybe 3 large washers with rubber or plastic inbetween. The drivers side stack is noticably crocked (not a straight stack).

We are the 2nd owners, have no vehicle history other than what we can see. It appears to be well maintained and all stock parts other than the rear panel around the license plate which was changed to the body color of the car. From the factory it was black (I believe). We bought it with 3000 miles 2 years ago. Guy from MI owned it and he gets a new one every two yrs.

My wife added that the noise is heard only when going over bumps and seems to lessen when the car warms up. It is a very high pitched, short metalic squeek. (her description)

 

Could be one of many things and likely not the height adjustment bolts... though I wouldn't rule it out.

When cold, grab the exhaust pipes and shake them around... go under the car if you can and look at the entire exhaust system... you could have some exhaust parts that are rubbing, a common cause of brief sharp squeaks when hitting bumps.

Another possibility is some part of the front or rear anti-sway bars causing the squeak, a bushing or end link etc.

I'd think that as long as you still have the rubber padding on the height adjustment bolts, these likely won't squeak since there is a lot of pressure on them, I don't think those pads will "move" unless maybe you become airborne. Though if the previous owner did mess with the lowering bolts and messed up the pads, then anything goes I guess. But if the car appears stock and the suspension seems perfect overall, it's likely that the height adjustment bolts were never touched.

Finally, if only your wife can hear the noise and YOU can't hear it, just FORGET about it!



EDIT: if you really suspect the height adjustment bolts, you can raise the car, then jack up each end of both leaf springs (one at a time) until the adjustment bolt pad rises up OFF the control arm, then smear a little bit of silicon grease under the pad, then lower... and repeat for all four corners. I actually did this on my car when I was performing a height adjustment, seemed like a good idea at the time even though I did not have any squeaks... car is still quiet. If you raise the pads, before adding any grease, check to make sure the rubber is intact and you do not have any metal to metal contact. If you do, then this may be an issue and you may have to swap in one or more new adjustment bolts. If so, get stock bolts and have them adjusted stock, not lowered.