Front End Noise
 

I have a 2001 SSEI and love this car as a daily driver. I bought from a good friend who had it as his company car. Bought it off lease with 49000 miles. Here is my problem. I have replaced both front hub assemblies and the left CV shaft because of a growling problem in the front end. The hubs turned out to be the problem and as I suspected by researching this site is not uncommon. However, now that the growling noise has been eliminated, the front end now makes a very loud and annoying pop when steering wheel is at extreme right or left and the suspension is being loaded, like going over a curb.

When I replaced the CV shaft, the NAPA store where I got the shaft had the wrong shaft listed in their book. Got the shaft home only to realize during attempted install that the original shaft has a 34 tooth spline wheras the replacement according to NAPA had 35 teeth. Went back and got the shaft spec. for the base bonneville and it had 34 teeth. The shaft installation went smoothly. After the install is when I first noticed the loud bang when the steering wheel is turned and the suspension gets loaded. Not understanding why this could be, I decided to put the original shaft back in to see if this could be any part of the puzzle. Could not get the new shaft back off. The spring clip has really got the new shaft locked in place. In fact, the output shaft of the tranny pulled out about 4 inches. Being complete pissed by this point, I left the new shaft on rather than make more problems. With the car up on stands at all four corners, everything seems to operate very smoothly. With the engine running, in Drive, the wheel can be turned lock to lock with the hubs spinning and no problems are visible. Only when the car is on the ground with the suspension compressed some does the banging take place.

After reading almose every post on this forum, I now believe that the problem is with the upper strut mount and bearing. I have the car scheduled to go to the local dealer, however, if the problem is the upper strut mounts, I'd rather just buy the redesigned mounts and install them myself and then just get it re-alligned.

Any input from those on this list would be appreciated.

A couple things come to mind

Steering intermediate shaft
Sway bar end links.

Thanks for the response Bill. I don't think the bang I am hearing is the Intermediate Shaft because I don't notice any vibration in the steering wheel when the bang occurs. I guess I could undo the stabilizer bar on both sides and see if that eliminates the bang, but again it sounds more like the strut spring snapping off of the spring perch. I have read some info here about lubricating the upper strut bearing assembly. I'm wondering if the upper strut tower is bound up and the spring is unloading off of the spring perch.
The sound is coming from the driver's side.

To check the spring on the strut bearing, put the car on dirt or somewhere the tires turn a little easier than on blacktop. Have someone hold their fingers on the spring while someone turns the steering wheel slowly from stop to stop. That's what my service manager did to test mine. I got a twang sound at times. Varied with temperature and load and whatever.

Yes, I would take a good close look at the left strut. Also might want to look at the control arm bushings while someone is turning the wheels. Suspension at different loads & geometry place burden on the bushings.

I have had a problem similar to this several times with the sway bar bushings. I have urethane ones and have had to periodically lube them. This may not apply to stockers but I thought I'd mention it.

What is the last thing you did to the car before this latest problem? It was changing the left CV shaft right? Do you think in any way this attributed to the current problem?

The last major change before I noticed the noise was changing the left CV shaft. I did in fact try to change the new shaft back to the old shaft, but could not get the new one back off. The local dealer now has the car and called to tell me that they think the steering rack is the culprit. They want almost a grand to replace the rack. I told them to not replace the rack as I can get a AC Delco rack for $320 and do the wrenching myself.
We'll see if the rack is the problem but I doubt that it is the problem.

After I replaced the CV shaft, I had the car up on stands at all 4 corners and had my wife put the car in drive and let the front wheels spin while turning the steering from lock to lock. I noticed no abnormal noise. You would think the the misalignment of the CV shaft would be at the worst possible condition with the suspension hanging due to the fact that the car is on stands at the rear and front cradle positions, but all seems to be very quiet. When weight is on the front end and the car is rolling, the noise re-appears when loading the suspension with wheels turned. Also, if you are rolling and apply agressive steering wheel input, the noise is prominent, however if the car is not rolling and you apply the same agressive steering input, there is no noise. That's why I don't think it's the rack. I did check the upper strut mount on the left side to see if it was sticky but it is very smooth as well. I'm baffled.

I applaud your your intension of doing the wrenching yourself, but I agree, I don't think it's the rack. I'm still suspicious of the second CV shaft Napa sold you. It seems to me, you should be able to remove it as easy as the original. I'm just going by the logic of simple deduction. I wish I could be of more help. :?

Put the rack in last night. Was not nearly as difficult as I thought it might be. Have done many racks before so I new what to expect and was pleasantly suprised to have completed the job in just over 3 hours. Did not get a chance to drive the car as it was late. One question though, does the intermediate shaft have the same flats on the interior side as the engine bay side? I installed the rack and it appears that there will be little adjustment for allignment on the right tie rod end. In order to try to even up the adjustment, the wheel inside the car can only be adjustable in 360 degree revs of the steering wheel since the shaft has flats and a scallop for the bolt to go through. I needed about 90 degrees of variability. If the shaft inside the car has no flats on it, then it isn't a problem, but if it is just like the engine bay side, than the allignment tech may have to pull a trick out of his hat. It looks like it will be real close to getting the allignment right with the steering wheel pointed at 12O'clock.