dragoscscc

Posted this in the tech/misc section but no help. Thought I'd try this section.

I have this clunk/thump from the rear of the car whenever I go over uneven surfaces. What's the best way to go about finding it?

2000 Prelude, 153K miles, all stock driven in NE Ohio (some rust)


All 4 struts were changed at 127K (maybe 2 years ago, KYB GR2 I think) along with the rubber spring supports on top (whatever they're called) and the four strut rubber mounting pieces on top.

There is a TSB for the rear shock mount collar where it's either replaced with a shorter one or cut down by 2-3mm. That way you should be able to tighten the top strut mounting pieces tighter against the frame to reduce the knock. That has been complied with.

I went in the car and took EVERYTHING out of the trunk. Spare tire, trunk lining, jack, nothing left. No fix.

Checked the shock absorber and the cover (inside of the spring) to make sure they were not hitting. Checked the shocks themselves for leaks also. All is good there.

Made sure the top springs/struts were tightened. No fix.

Checked all the bushings on the rear suspension. Used a pry bar to try to move suspension components and visual check. Some wear (cracks in the rubber bushings) but nothing excessive...

Tried jumping up and down in the trunk (195lbs) could not duplicate the sound.

Tried driving on uneven concrete with the e-brake on, made no difference.

Moved the exhaust/heat shields/gas tank by hand, all quiet.

Checked the anti roll bar bushing and anti roll bar ends with and without load on the suspension. No play, no noise. Some wear on the bar ends boots, but still intact with no play/noise.

Checked the lower, rear and upper ball joints. No play/noise.

Checked the trailing arm bushing, again not new, but no metal to metal contact.

Adjusted trunk stoppers in and out. No real difference.

Drove with the trunk open. Still there.


The sound can be easily duplicated when driving on uneven concrete, 20MPH or so. I can't tell if its coming from the right or left suspension, if it's the suspension to begin with or coming from somewhere else all together.

Driving anywhere else the car is quiet.

The sounds can be best describes as oil canning, but muffled. Or if you take a big thin piece of sheet metal and shake it back and forth. It seems like it happens when the suspension drops from a higher surface onto a lower one or when catching the lip of uneven pavement. I'm not sure if it's because the rear end drops suddenly, is jolted upwards or the rear wheels are jolted rearward.



How do I go about narrowing this down? I don't want to just throw money at this.


The only discrepancies I've found is some play in the upper control arm bushings where it connects to the frame and trailing arm bushings (side to side, nothing front/back/up/down). No metal to metal contact though... When I pound on the lower part of the fuel tank or on the lower part of the bumper cover lip it does make a "thump" noise but It doesn't sound the same


What else can I check? How can I eliminate other components? Any help would be greatly appreciated.


Finally got some more people inside of the trunk to listen to the sound. It seems to be coming from the passenger side (maybe more potholes on the outside of the road than near the median). One of them said it seemed to be coming from the lower suspension cross member right aft of the fuel tank, on the pass side...

How do you check the swaybar endlinks? With the car on jacks (both wheels off) i tried to move the link every which way. No play in the lower or upper joint. I can rotate them on the ball joints themselves but they are fairly stiff. Need both arms to turn them. I'm halfway tempted to disconnect them and take it for a spin, just to see if anything changes, but I have a feeling that I wont be able to get them off in one piece.

What about the upper control arm bushings? When using a 2-3 FT prybar I can get some side to side (FWD/AFT) play from the bushings. But up down/side to side they seem to have no give.

Why cant I duplicate this by jumping up and down in the trunk? How is that any different than driving down the road?

Dragos

alphalanos

When youre jumping up and down its the car compressing down the suspension. When youre driving the suspension is more being pushed up, applying different forces to the bushings. I would think its a bushing issue. I would start with the cheapest bushings, and sway bar links, and work up.

dragoscscc

I'm gonna replace the sway bar end links just because the boots are just about thron from dry rot. Fairly certain it won't fix it but who knows.

If that doesn't work I guess just take the strut assembly off and dissasemble it...

D

dragoscscc

FIXED!!!

Well after taking the rear struts apart for the 10th time (not really but it seemed like) found the two rubber bushing on top of the strut mount were installed upside down.

http://www.hondaautomotiveparts.com/...SHOCK+ABSORBER

#13 top and bottom are the same part, but the tapered portions were installed towards each other instead of away from each other. The manual is kinda vague on this. Looking at TSB 00-090 and the link above it finally clicked in.

Maybe this can help somebody else.

D