Growling/Clunking noise in rear while accelerating hard in 1st or 2nd ??

[Guest]

^ Yes, you don't. So my theory can be put to rest.

[schwinn]

Ok, so the rear bushing seems to be the key here... has this changed for newer vehicles, versus older ones? (I see unclemat showed a photo of the SpecB having a "filled in" version... I wonder if this is used on all newer vehicles?)

 

SeeeYa: Your particular fix was to "fill in" the spaces within the bushing?

 

Did anyone find an aftermarket method for performing this, other than simply filling it manually, as SeeeYa did? (ie, any bolt-in poly-insert thing?)

[Guest]

Just checked. Trailing arm bushing part # is SAME for all MY05-MY09 years. Only SpecBs get different bushing in the alu trailing arm.

[SeeeeeYa]

Ok, so the rear bushing seems to be the key here... has this changed for newer vehicles, versus older ones? (I see unclemat showed a photo of the SpecB having a "filled in" version... I wonder if this is used on all newer vehicles?)

 

SeeeYa: Your particular fix was to "fill in" the spaces within the bushing?

 

Did anyone find an aftermarket method for performing this, other than simply filling it manually, as SeeeYa did? (ie, any bolt-in poly-insert thing?)

 

Yes, filled in using the same method as for the rear diff bushings (detailed in here somewhere). That is, pieces of plastic pipe cut to fit the space, coated with 3m poly goop and shoved into the bushing which had already been doctored with the 3m goop, then the remainder of the bushing filled and smoothed with that goop until the bushing looked solid. Let cure without moving car for two days. Thereafter, in combination with the other similar measures with the rear diff and the Rallitek transmission insert, NO MORE of the noise everyone knows about.

 

I understand the reluctance to perform this corrective measure, as anyone who has messed with that nasty stuff knows what an incredible mess is involved. You must do both sides and get it ALL filled and smoothed until it looks solid. There is no tool but your hands and fingers. But eventually they will look normal again. The results are the issue, not dirty hands, they're just part of the job.

 

Again, anyone who has drag raced, successfully, knows what is going on. What's amazing is, older muscle cars had far better bushings than these to begin with, but even "solid" rubber bushings caused problems, so the solution was usually to eliminate those particular bushings altogether with steel replacements and hard Delrin or poly bushings everywhere else. There can be NO movement when the horsepower gets serious. I have a number of record holder certificates from those times that verify my understanding, fwiw.

 

I have inspected my 09 3.0R's bushings and unclemat is correct, they're the same. However, I doubt I'll have any problems.

[schwinn]

Yeah, the gooping and the 2-days of no driving puts a crimp in that method... seeing that this is my daily driver and only car. When the weather warms up, I suppose I could run on the bike when the car is "curing"... still, I'd prefer an "insert style" device.

 

Do you have a good picture of the bushing/part that we're supposed to attack? (Is it in my picture, by chance?)

[LittleBlueGT]

Yeah, the gooping and the 2-days of no driving puts a crimp in that method... seeing that this is my daily driver and only car. When the weather warms up, I suppose I could run on the bike when the car is "curing"... still, I'd prefer an "insert style" device.

 

Do you have a good picture of the bushing/part that we're supposed to attack? (Is it in my picture, by chance?)

 

It is the suspension bar (rear arm) that is the biggest movable piece we have in the rear. It runs the same length as the car, it pivots from a point just under the dog-leg.

 

I should have the bushings (spec-B ones) in within a few weeks.

[LittleBlueGT]

It is number 13.

 

http://i248.photobucket.com/albums/gg194/littlebluegt/Reararm.jpg

[LittleBlueGT]

And the bushing looks kinda like this:

 

http://i248.photobucket.com/albums/gg194/littlebluegt/Reararmbushing.jpg

[Impulse]

hey just to chime in, i just found this thread and i'm an 06 owner up here in the north east that also experiences an annoying growling noise when i accelerate hard, especially in 1st gear under heavy throttle. in 2nd gear i can actually control when the growling starts by throttle position. all this is very prevalent in the cold that we get.

 

very interested in this thread as it *seems* like i am getting less power to the ground with the growling, but not sure, i almost always react by reducing power

[mccorry]

Well.. I can say that this is definately due to ride height / compression of the rear springs.

 

I can still get the growling in 1st and 2nd under hard acceleration... esp. when turning right.

 

I have also noted over this past winter that I've gotten it with people in the back seat.

I've also hear it several times when the suspension is loaded up (compression) (driving on a rolling road... at the bottom of the trough between hills).

 

On all three cases.. the only common item is ride height / spring compression.

It is not soley dependent on power output... but moreso rear suspension compression.

Edited February 16, 2009 by mccorry

[Guest]

^ Speaking of which.... whenever rear trailing arm is reinstalled the FSM calls for torquing the hinge bolt with the car with wheels on the ground - so the bushing is secured in "neutral" position. Those who are lowered should try loosening those nuts, which should release the bushing to it's new neutral position and torque it down then.

 

I recently replaced my arms so had to thru it (bit of a pain, had to use ramps). Since I alternate between stock height suspension in winter (JDM Bilsteins) and lowered in summer (coilovers) I tried to catch them in a "middle of the road" position by having a buddy (hello atc5!) sit in the trunk (along with a trash can and 50 lbs. bag of salt) while I was torquing these nuts down

Edited February 16, 2009 by unclemat

[LittleBlueGT]

Well.. I can say that this is definately due to ride height / compression of the rear springs.

 

I can still get the growling in 1st and 2nd under hard acceleration... esp. when turning right.

 

I have also noted over this past winter that I've gotten it with people in the back seat.

I've also hear it several times when the suspension is loaded up (compression) (driving on a rolling road... at the bottom of the trough between hills).

 

On all three cases.. the only common item is ride height / spring compression.

It is not soley dependent on power output... but moreso rear suspension compression.

 

 

I still think it is that bushing on the rear arm. Different ride heights might make it worse, but the ride height/weight in the car is not the culprit.

[SBT]

Yes - I've heard it a few times, and all post lowering springs so I suspect it's related to the rear suspension compression, and the dynamic changes to the rear articulations that are due to that, more than bushings per se.

[schwinn]

LittleBlueGT - thanks for the clear ID there... I'll check it out.

 

mccorry - Quite true. For me, in slightly warmer weather, it would be worse when the car is loaded up with people (lunch trips during work days, for example, when there are 4+me in the car.) In colder weather (such as the 20-30F we've been having here near Boston) it happens pretty much all the time. Granted, I'm not shy about using the throttle... but it concerns me, so I back off if possible (damn those short highway onramps).

 

Unclemat (and Subietonic) - excellent point, and a simple test. I do have STI springs and JDM Bilsteins, so that makes sense. I'll have to give that a shot. Is there a torque spec on those bolts for when I retighten them?

 

Maybe I'll take a photo of the bushing to see what it looks like before/after... it's gotta warm up a bit more before I do this though - it's friggen cold out there!

[Guest]

111 ft/lbs. for the trailing arms "hinge" bolts.

 

To access them you'll have to remove these "connector" pieces that bolt to subframe and the trailing arm bracket. 82 ft/lbs. at the bracket, 129 ft/lbs. at the subframe.

[hutru01]

My wagon does this as well and I am just Stage 1 now. It was much worse with Stage 3 though and I did have 18 inch rims and tires at the time. Now I am just running stock rims/tires and it still makes the sound. I figured it was the tires rubbing from squat. Oh and I am on Bilstein HDs/Pinks.

[Gmoe]

Add me to this list. Stg. 1 sedan, stock othewise. Symptoms sound exactly the same as everyone else. I'm on stock suspension though. My thread because my search skills suck. Only seems to happen with passengers/weight.

 

Is there any damage/harm being done from this issue, or is this just an annoying noise problem? I'll just remove the back seats and be done with it.

[legwag]

I did a quick search on this posting to see if this problem can be produced on a dyno or not. I ask because I am getting the car dyno'd this week, should I be checking anything out while getting tuned to help address this problem? I have the noise too and I am assuming it is only going to get worse/more frequent with my upgrades.

[Gmachine]

I wonder if i or anyone can replicate this problem on a 4 wheel dyno?

 

It would help so much if someone could look at, and listen to the car while this is occuring. For me as i have posted above, 5th gear cruise at 60mph... plant foot wait for boost to come in and Bingo! Driveline growl.

 

Start this pull from a higher speed,say 75mph and there is no growling.

 

Posted that many pages ago. Don't know if this can be done,since most dynos are in doors where it is warmer. If your tuner wants to give it a shot put 2 guys in the backseat and go for it. I suggest a 5th gear pull starting at 50/55/60 MPH. That is when this happens for me.

[05lgt5spd]

mine growls too. maybe the car is just angry

[GTTuner]

Add me to this list. Stg. 1 sedan, stock othewise. Symptoms sound exactly the same as everyone else. I'm on stock suspension though. My thread because my search skills suck. Only seems to happen with passengers/weight.

 

Is there any damage/harm being done from this issue, or is this just an annoying noise problem? I'll just remove the back seats and be done with it.

 

Same here, weight in the backseat amplifies the problem, as does cold weather when my car runs like a "raped ape". I noticed my jounce bumpers look like they are getting crushed from the rear end squat. I rarely ever have passengers in the back.

Edited February 25, 2009 by GTTuner

[schwinn]

Gmachine - 5th gear? My car doesn't seem to make the noise in higher gears - only lower ones. I would have suggested trying the dyno test in a lower gear, not a higher one.

 

Also, when strapped into the dyno, the vehicle may be loaded "differently" than how it is on the road... if you can replicate the road-loading (ie, don't strap the subframe, for example) and see if that noise comes back?

 

Cold weather and rear-seat loading seems to be the key... if you can replicate that on the dyno, it would help.

[Gmoe]

^This. I can't reproduce it unless in 1st, 2nd, rarely 3rd in the right conditions. Though I only had about 20 minutes of test time with people in the back. Maybe I outta rent a few people and strap them in the back seat for a couple hours before the weather turns warm again.

[Gmachine]

Gmachine - 5th gear? My car doesn't seem to make the noise in higher gears - only lower ones. I would have suggested trying the dyno test in a lower gear, not a higher one.quote]

 

5th gear for me. I am at stage 2+ not dyno tuned. Can't explain why my car is this way for sure,but i have given it some thought. It's as if what ever is loading up and "growling" in the driveline. Has more time in top gear to load up as the engine pulls through the rev band. If i start at 65-70mph i get no noise.

 

In the lower gears i have tried to replicate this at various rpm start points,but the car just accelerates smoothly to redline with no issues.

Edited February 26, 2009 by Gmachine

[Wangspeed]

I'm with Gmachine. 1-4 is great. No noise. 5th is bad!

 

Warren