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Discussion Starter #1
Ok, so how many Insight owners are experiencing what I call a "scrunching" noise that comes from underneath the front of the car when you drive over speed bumps or anything that makes the front suspension flex? This is important because the source of the problem is not a simple one, unfortunately.

My adventure:

Ok, first I was suspicious of the front sway bar mounting grommets, so I removed those and lubed them with waterproof silicone grease and reinstalled them. No difference whatsoever, still scrunch, scrunch, scrunch, goes the front suspension when I drove over bumps and humps in the road.

Next, I decided to take a peek at the front suspension lower control arms and found the problem. The large, round rubber mounts on the rear of the control arms turned out to be the source of the problem. These are the round, pressed in rubber inserts on the aluminum lower control arms that look much like the rubber engine mounts. Why are they scrunching you ask.......deterioration of the rubber causing the center portion of the mount to rub against the pressed in shell of the mount when flexed. I discovered this by removing the three bolts that secure the mount in place and used the center bolt to flex the rubber hub of the mount. The rubber hub is beginning to split and sqaucks loudly when it comes into contact with the shell. (See page 18-19 in the service manual for a detailed illustration of the control arm). I also have a couple of digital photos of the lower arm if anyone can host/post them for me?

The fix:
Well, naturally I wanted to take the car straight to Honda since my car is still under warranty, but it was late in the day and I didn't really feel like driving 30 miles each way to argue with the service department. I put a dab of silicone grease in the open slots (air gap between the rubber hub and shell) of the mounts. I then test drove the car, no more noise, gone completely.

The true fix:
Personally, I would have to say that the rubber control arm mount inserts are a flawed design! No joke! The type of mount used on the lower arm is best suited where a vibration damper is needed, such as an engine mount. This type of rubber mount is also designed to flex in a lateral fashion (the rubber is supposed to flex parallel to the shell). In the case of the lower control arm, the rubber flexs left-to-right of the shell. Not Good!! This places a lot of stress on the rubber and can cause premature failure. I spoke with the parts department at Honda to see about repalcement mounts. No go....you have to buy complete lower arms that come complete with new mounts and new ball joints. What a crock of s---! The price for the right side arm...$252.80. The left side arm...$253.50. I asked the parts guy if he had been selling a lot of replacement control arms and he said that I was the first to inquire about the arms. :roll: I then spoke with someone in the service department and got the same speel. They claim to have never heard of any problems with the lower control arms or mounts. No recalls or TSB's, nothing! The part numbers for the control arms are also the same for 2000-2006, so I have no idea if the newer arms have a better mount design. I somehow doubt it!

What should we do:
Before applying any type of grease to the mounts, I recommend trying to get Honda to resolve the problem since we now know where the problem is, and can prove it. Those that have older model Insights and are experiencing the noise problem will probably have more deterioration of the rubber portion of the mounts. I say we all try to ban together and get Honda to fess up to this potentiially serious defect in material design!!
How about it?? Take your Insight to the dealer and if they fuss, have the mechanic(s) apply some silicone spray to the mounts and see what they say after that. 8) Not many Insights were sold, so we all need to ban together and make Honda fess up to the flawed mounts ASAP. The deteriorating/deteriorated control arm mounts are going to foul up the front suspension alignment something awful as well as make the undesirable "scrunching" noises.
 

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Count me in!

Thanks for the detective work Dave.
Everyone that has an Insight will experience this problem. That fact is the most drivers probably are experiencing it but since it is not a constant noise they either disregard it or have not noticed it yet.

I have noticed that the sound becomes less dramatic in warm weather (probably because the rubber bushing is more flexible in the heat) and disappears completely in the rain (water acts as a very temporary lubricant)

Unless there are numerous complaints from very unhappy customers, Honda will not likely take any action.
 

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Discussion Starter #4
Re: Count me in!

Steve C said:
Thanks for the detective work Dave.
Everyone that has an Insight will experience this problem. That fact is the most drivers probably are experiencing it but since it is not a constant noise they either disregard it or have not noticed it yet.

I have noticed that the sound becomes less dramatic in warm weather (probably because the rubber bushing is more flexible in the heat) and disappears completely in the rain (water acts as a very temporary lubricant)

Unless there are numerous complaints from very unhappy customers, Honda will not likely take any action.



Steve C........take a peek at the mounts on your car and see if they are in sad shape. If you put the frontend up on ramps, you can then safely remove the mounting bracket for the rear control arm mount to get a good look at the rubber hub. I'm pretty upset with both the lousy design and the fact that a lot of innocent Insight owners are probably unaware of the problem. When the mounts fail altogether, the steering geometry will surely become quite unstable. The poor rubber mount design may be partly to blame for the poor tire tracking that I experience a lot of the time, especially while driving in the rain, and the premature wear characteristics of the front tires. I really hate to see Honda get away without doing anything to resolve the problem! The only other thing I can think of is to perhaps replace the rubber mount with a urethane mount. New control arms from Honda for big $$ aren't going to solve the problem if the new arms have the same mounts. I may consult with a company called "Prothane" that specializes in urethane engine and suspension mounting hardware and see if they can help me/us out with a urethane swap for the rubber mounts.
 

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My BF works near Costa Mesa. If you can talk in detail to someone there and specifically let me know who we need to talk to, then I'm sure I can arrange for a visit in the next few weeks.
 

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I've done some bushing replacement on an Infiniti Q45, and I'd caution anyone thinking of going with urethane to consider that using urethane would increase the noise, vibration, and harshness of the suspension in a negative way. The suspension bits may need replacing, but probably with a harder rubber, similar to the Nismo replacements that Nissan sells for their cars. - Pat
 

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Discussion Starter #9
The front bushing on the lower control arm is a standard pivot type bushing, while the rear pressed-in insert is truly not designed to pivot in any fashion. Why the engineers at Honda did this on the Insight really blows my mind. Common sensible logic would say that they should've used a pivot type bushing on both the front 'and' rear of the control arm. 8)

Urethane is less flexible than rubber but is also more durable. The problem that I forsee is that I have my doubts as to whether soft rubber, hard rubber, or urethane will hold up to the twisting action of the rear mount for any long period of time. The stiffer urethane would provide more support for the control arm and also help reduce any flexing or slop in the rear mount, thus helping to reduce front tire wear and steering problems by keeping the front suspension geometry in check. Hard rubber would accomplish nearly the same results, but most likely would not last as long as urethane considering the constant twisting of the material.

I hope I'm not confusing anyone at this point! To help make the picture more clear and simple....picture a nylon dog bone (yes, those nylon rubber "nylabone" dog bones that you see in pet stores) :). Now, grab one of those rubber bones at each end with your hands, clamp the center portion of the bone in a vise, then twist the ends of the bone with your hands. This is exactly the motion that the rear mount on the lower control arm sees. Twist the nylon dog bone or the rubber mount long enough and what will happen? The ends will eventually split and break off. In the case of the Insight, the rubber mount splitting completely could raise serious havoc with the front suspension. Remember, my Insight only has 30,289 miles on it and the rubber is already beginning to split and break loose from the mount shell.

It really wouldn't hurt to have an engineer at Prothane look at the problem firsthand and see what he or she thinks about the dilemma. Being in a family of engineers myself, I wouldn't be surprised if they took one look at the control arm design and said "who's hairbrain idea was it to do that". :lol:

I'll contact Prothane tomorrow and see if they would be willing to have an engineer take a look at the control arms on the Insight.
 

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Discussion Starter #10
cattygurl said:
My BF works near Costa Mesa. If you can talk in detail to someone there and specifically let me know who we need to talk to, then I'm sure I can arrange for a visit in the next few weeks.
Good deal! I'll see if I can arrange something with Prothane in the AM.
 

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Discussion Starter #11
I just thought I would mention that at first glance, I thought the rear control arm mount was a pressed-in shell filled with solid rubber. Such is not the case. The rubber only attaches to the shell at the front and back with an air gap on each side. So, another way to view the probem would be to clamp the center portion of the mount with the bolt sleeve in a vise and then twist the shell back and forth until the rubber deteriorates and splits.
 

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Discussion Starter #14
gomarlins3 said:
Thanks for the detective work. I will have to try the silicone idea.
Take your car to the dealer and let the mechanics apply the silicone to prove the defect. We need to start educating the Honda service departments and forcing the mount issue as much as we can in hopes of getting a recall established.
 

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so is the scrunching noise a little warning sign that something is going to break? or could this part last a long time without damaging anything else?
 

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Discussion Starter #16
Allnighte said:
so is the scrunching noise a little warning sign that something is going to break? or could this part last a long time without damaging anything else?
The scrunching noise is due to the rubber in the control arm mount deteriorating and starting to split. Once the rubber starts deteriorating, it will only get worse and eventually fail altogether. You/we really need to have this problem solved before a lot of Insight owners are driving around with busted control arm mounts. The scrunching noise is definitely a telltale sign that the rubber mounts are failing.
 

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Since I wouldn't want any Insighter to spend any money early unnecessarily, such a "noise" commonly will warn by degree. Once a tapping begins don't wait any longer.

But if we're talking about the bushings on pg. 18-19, specifically bolt 1 and the other in the upper most top right of the drawing I'd first try tightening the bolts +10% of torque. These bushings have a bonded inner sleeve. Its this sleeve that sometimes shifts allowing the creak.

HTH! :)
 

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Discussion Starter #18
John,
The front bushings are fine on my car. The rear donut shaped mounts are the culprits. I understand what you're saying about the inner sleeve being allowed to cock or move slightly if bolt #1 of the mounting bracket were loose enough to allow the shift, but I would think that would result in more of a mechanical creaking sound rather than a sound that resembles rubber binding against metal. If you remove the mounting bracket (C) by removing bolts 1, 2, &3, and then insert bolt #1 into the sleeve of the mount and use that bolt to move the rubber hub through it's normal range of motion, you'll hear the audible scrunch sound when the rubber hub comes into contact with the round metal shell of the mount. What's even worse is that if you look closely at the rubber hub while moving the hub and inner sleeve with the bolt, you'll see where the rubber is beginning to tear and seperate from the shell. At least I did, anyway. The rubber hubs in the mounts get twisted pretty heavily when you drive over speed bumps or anything that makes the front struts compress or extend. The rear rubber control arm mounts really just aren't up to the task of the rubber hubs being constantly twisted. Definitely an engineering flaw in my honest opinion. That particular type of mount really just isn't designed to have the hub be twisted, but rather the rubber hub should be "pushed and pulled" like an engine mount of the same design. Both forms of stress on the rubber will eventually lead to failure, as all engine mounts of this design do have a tendency to fail, but twisting of the hub is definitely not going to be tolerated without failure occuring for any long period of time, especially in climates where the rubber is subjected to temperature changes and road salt during the snow season.

HTH!! 8)
 

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I had the same creaking noise as others have reported (more in the
winter than summer and only noticed when going slow over bumps).
Today I completely removed the 3 bolts and bracket. The manual says
then should be torqued to 51 ft lbs. I could easily remove the three bolts
with a small ratchet so it appears they were not tightened much. The
middle bolt was bone dry so I force squeezed some grease into the
rubber and coated the bolt. Since I may have to do this every couple
of years, I only torqued it to 40 ft lbs (much tighter than what it was)
I did not to strip any threads because they are embedded in the chassis.

I did not see any wear on the rubber but my car only has 53,000 miles.
(or maybe I'm not looking at it right - I did notice that I could stick a
bolt inward and pull to one side and see the rubber move slightly).
Maybe it just needs to be lubricated every so often. The good news is
the noise is gone (I went over some speed bumps to check). I think
what Honda needed was a small flexible boot to cover this area so it
could be protected from the weather or a splash guard.

Thanks Curious Dave for finding the problem area. I was going to
start looking in a couple more weeks where the noise was coming
from but I probably would have checked the shock area by mistake.

JoeCVT - Just your average CVT owner
 

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Discussion Starter #20
I'm glad I was able to help! The interesting part of the whole problem is that the scrunching noise was never there when my car was new and didn't start until around 25,000 miles. That leads me to think that the rubber is deteriorating/deforming or softening enough to allow the hub to shift off center from the shell and rub against the shell when going over speed bumps, etc.. Silicone grease is really just a temporary band-aid in my opinion to stop the annoying noise. We really need a better fix!

I tried to contact Prothane today, but they closed early at 12 noon PST. I will try again on Tuesday of next week.

I'm also thinking that replacing the rubber mount with some type of lubricated and sealed ball joint would be a good cure. No more (or at least limited) flex in the control arms, less skewing of the suspension geometry in general, and less front tire wear. The downside would be less ability to absorb shock if you were to accidentally hit a curb. Another approach might be to place urethane inserts in the air gaps to help keep the rubber in check and centered within the shell. Any other ideas??
 
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