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

[Leonardo]

Well, I was thinking more like this:

 

KSB750

The subframe lock kit is designed to lock the rear subframe on the Impreza. It allows for more precise alignment of the rear wheels and limits the amount of rear subframe movement under cornering loads, which can result in poor dynamic alignment settings.

http://www.subaruwrxparts.com/products/images/ksb750.jpg

 

I was looking through a vendors site for those as I have them still from my old 04 STi and was wondering if they would fit and they have them listed under the 05+ Legacy as well.

 

Wonder if Turn In Concepts can check both the subframe lockout bolts AND the Subframe bushing compatibility.

[whitetiger]

where in the subframe would these bolts go? are they replacements for the main bolts?

[Leonardo]

On the Impreza, between the f/r bushings on either side, there is a hole you just screw these in and "bypass" the bushings and thus it would be bolting the subframe to the car.

 

Instructions:

http://www.whiteline.com.au/docs/instructs/200_SB750_draft.PDF

Note that it mentions ...certain Legacy models.

 

Review (on Imprezas):

http://forums.nasioc.com/forums/showthread.php?t=1249968

[LittleBlueGT]

^^^

 

From the thread:

 

TiC and the Whiteline instrux say:

 

"should not be used for extended periods as it may lead to premature chassis wear." they suggest that it should be removed between races.

[LittleBlueGT]

And as I read further:

 

 

Mine have been in for 70,000 miles wih no problem.

I had the same concern when I got them, but that disclaimer is just for "legal" purposes.

[LittleBlueGT]

I think (if they fit our cars) that it would be worth trying. It looks like NVH issues go up a lot. But if they work, then we know what the problem is,and can steer our efforts into that direction and take the bolts back out.

 

Might not be a bad idea for those of us that track our cars.

[Leonardo]

true!

 

I will report back if I see or not the holes for them unless someone has a LegGT on a lift right now.

[LittleBlueGT]

true!

 

I will report back if I see or not the holes for them unless someone has a LegGT on a lift right now.

 

-23 here right now, so I hope you do it!

[Leonardo]

[whitetiger]

I dont think ther are hole like that on our rear subframe. our rear subfram is for a multilink rear setup. our subframe is alot bigger than the impreza one and the mount bushings look totally different.

[Leonardo]

wonder if someone with access to a dealer parts system can check the numbers of the bushings against the ones from the 08 Impreza.

[schwinn]

I think (if they fit our cars) that it would be worth trying. It looks like NVH issues go up a lot. But if they work, then we know what the problem is,and can steer our efforts into that direction and take the bolts back out.

 

Might not be a bad idea for those of us that track our cars.

Exactly... if we can test to see that this is where the problem is, then we can engineer a better solution. I suggested the rubber pad idea, but a fixed-bolt idea might be another way too... barring the NVH issues. I certainly would not want the higher noise on my car, so buying and then not-using those bolts makes no sense for my application, but if anyone wants to test it that way, it would certainly provide a valid point of info.

 

Any takers on the experiment?

[Leonardo]

If you read post 626 again:

 

Well, I was thinking more like this:

 

KSB750

The subframe lock kit is designed to lock the rear subframe on the Impreza. It allows for more precise alignment of the rear wheels and limits the amount of rear subframe movement under cornering loads, which can result in poor dynamic alignment settings.

http://www.subaruwrxparts.com/products/images/ksb750.jpg

 

I was looking through a vendors site for those as I have them still from my old 04 STi and was wondering if they would fit and they have them listed under the 05+ Legacy as well.

 

Wonder if Turn In Concepts can check both the subframe lockout bolts AND the Subframe bushing compatibility.

 

[LittleBlueGT]

Exactly... if we can test to see that this is where the problem is, then we can engineer a better solution. I suggested the rubber pad idea,

 

I think that may be the ticket.

 

There is likely just one particular (or maybe two) rubber bushing that shrinks just enough in the cold that he actually get some steel on steel contact where the bushing should take up all the movement.

 

How hard will it be to get at? Probably a RPITA. But possibly unbolting it, and putting in a thing rubber pad may be an inexpensive solution.

[Leonardo]

Probably a buching ring insert like the WL ones that looks like flat rings.

[SeeeeeYa]

I think if you were living in a cold environment you would still have that problem. What have you done that I haven't done?

 

I know you filled in your upper rear diff bushings with that 3M stuff. Well I have the WL poly rear diff inserts, and I can pretty much gaurantee that they allow less movement and are stiffer then the 3M stuff.

 

I have stiffer engine mounts, STI trans mount, Ralitek poly bushings holding the trans mount (can't remember the exact name right now).

 

My suspension sags very little (KW2s) on accel.

 

I only get it when it is about 20F or less outside, but I still get it.

 

 

FWIW my Beatrush front diff support bar is on the boat from Japan as we speak.

 

 

Maybe it is the rear suspension subframe. Maybe the rubber shrinks when it is colder, just enough to cause some contact somewhere?

 

The one I have done that you don't list as having done, is what made the final difference for me.

 

As for your inserts in the rear diff upper bushings, I can imagine they are a great product. I wish they had been there, or I had known about them, when I started trying to eliminate "The Noise." However, I don't have just 3M poly in those openings, I have cut-to-fit plastic inserts in them... the 3M poly just cements them in and fills in every iota of space the inserts don't. The inserts you have are a nice easy fix, I had to work for mine and I'm sure they are, at the least, as effective. They made a huge difference.

 

The Rallitek poly insert for my 5EAT mount made a difference, too.

 

I've had my Teins so long I don't remember any correlations, but it doesn't squat or dive either.

 

The thing I did that you didn't do must make a difference. Odd that no one, that I can remember at least, has also done it. Yet everyone still says there isn't any "fix" .... even though they don't fix all the things I have said numerous times fixed it for me, especially what may be the biggest problem of all.

 

I cannot replicate the kind of temps you have to deal with up there in the Frigid North, although from my thirty years in NE I can appreciate it. But until someone does ALL the mods I have, AND lives where it gets really cold, the final word on my fix is not in. Why doesn't someone (like you Mr. LBGT ) complete the job and fix the remaining bushings. Then we will know.

 

Until then I am going to continue to listen to people piss and moan over something I believe a little time, a little work, and very little money can eliminate.

 

Now, if you finish the job and do the same thing for your rear forward lower link/control arm bushings that you did for the upper rear diff bushings.... or what I did as outlined somewhere in this thread, maybe we could put to rest whether or not there is the fix I contend there is. Oh, I think that new support you're waiting on will help as well. Linky?

 

Think about it. All this big thread is about is wheel hop. Nothing more. The complexity of our suspension, however, makes our solution more complex. And, being wheel hop, until every piece of rubber has been replaced by steel there will be traces for anyone who wants to abuse their daily driver. For everyone else I think there is a realistic solution.

 

We await your final report . My preliminary report says I'm done.

Edited December 12, 2008 by SeeeeeYa

[LittleBlueGT]

The one I have done that you don't list as having done, is what made the final difference for me.

 

As for your inserts in the rear diff upper bushings, I can imagine they are a great product. I wish they had been there, or I had known about them, when I started trying to eliminate "The Noise." However, I don't have just 3M poly in those openings, I have cut-to-fit plastic inserts in them... the 3M poly just cements them in and fills in every iota of space the inserts don't. The inserts you have are a nice easy fix, I had to work for mine and I'm sure they are, at the least, as effective. They made a huge difference.

 

The Rallitek poly insert for my 5EAT mount made a difference, too.

 

I've had my Teins so long I don't remember any correlations, but it doesn't squat or dive either.

 

The thing I did that you didn't do must make a difference. Odd that no one, that I can remember at least, has also done it. Yet everyone still says there isn't any "fix" .... even though they don't fix all the things I have said numerous times fixed it for me, especially what may be the biggest problem of all.

 

I cannot replicate the kind of temps you have to deal with up there in the Frigid North, although from my thirty years in NE I can appreciate it. But until someone does ALL the mods I have, AND lives where it gets really cold, the final word on my fix is not in. Why doesn't someone (like you Mr. LBGT ) complete the job and fix the remaining bushings. Then we will know.

 

Until then I am going to continue to listen to people piss and moan over something I believe a little time, a little work, and very little money can eliminate.

 

Now, if you finish the job and do the same thing for your rear forward lower link/control arm bushings that you did for the upper rear diff bushings.... or what I did as outlined somewhere in this thread, maybe we could put to rest whether or not there is the fix I contend there is. Oh, I think that new support you're waiting on will help as well. Linky?

 

Think about it. All this big thread is about is wheel hop. Nothing more. The complexity of our suspension, however, makes our solution more complex. And, being wheel hop, until every piece of rubber has been replaced by steel there will be traces for anyone who wants to abuse their daily driver. For everyone else I think there is a realistic solution.

 

We await your final report . My preliminary report says I'm done.

 

I will put this simply, cause I don't have time (all due respect, and you know that).

 

I am fairly certain that my diff inserts are still more effective then your plastic inserts held in place with the 3M stuff.

 

I DID THE SAME THING ABOUT 1 YEAR AGO!!!!

 

Of course I did it after your write-up, thank-you.

 

That being said, I don't think it matters.

 

 

I would be willing to bet serious money that your car would do it too in the cold.

 

I have the Beatrush piece on order (pics earlier in this thread), but I don't think that will do it too.

 

 

The thing is in the winter it is soo ridiculously loud, and it happens so easy, it makes sense that the problem is what I described above. It sounds like someone is back there with a mini-jack hammer.

 

Long story short (I am sure you will reply, and I will have to explain further) you are likely incorrect in your analysis.

[Guest]

I'll see if I still get the problem with the Group-N engine mounts after I get my car on the road back. I used to have the problem with stock power levels (and lowered suspension).

 

If I do I'll certainly get the Group-N 08 Impreza subframe bushing and compare it to stock.

 

Pulling out the subframe is not that big of a deal, btw.

[SeeeeeYa]

I will put this simply, cause I don't have time (all due respect, and you know that).

 

I am fairly certain that my diff inserts are still more effective then your plastic inserts held in place with the 3M stuff.

 

I DID THE SAME THING ABOUT 1 YEAR AGO!!!!

 

Of course I did it after your write-up, thank-you.

 

That being said, I don't think it matters.

 

 

I would be willing to bet serious money that your car would do it too in the cold.

 

I have the Beatrush piece on order (pics earlier in this thread), but I don't think that will do it too.

 

 

The thing is in the winter it is soo ridiculously loud, and it happens so easy, it makes sense that the problem is what I described above. It sounds like someone is back there with a mini-jack hammer.

 

Long story short (I am sure you will reply, and I will have to explain further) you are likely incorrect in your analysis.

 

We both know it isn't about me being "right," it is about solving a problem. It is a problem for our senses and peace of mind. But worse, it can break things.

 

Now, regardless of which diff solution is better, you still have not said, definitively, that you have addressed the forward bushings in the rear LCA/trailing link/whatever!

 

The diff bushings are crap and have been taken care of satisfactorily.

 

The transmission(s) have their mountings addressed satisfactorily.

 

But on our cars the number ONE area anyone with a drag race history or understanding will look to FIRST is the same one on ANY car..... the rear lower control arm bushings!! Just look at these bushings, they are exactly like the diff bushings, full of air and progressively more squishy as they age. As I have said before, on my/any race car the entire arm was replaced with a box section piece with steel bushings, NO RUBBER. The reason why is the wheels try to outrun each other and that back and forth causes all the floppily LGT suspension to wind up/wind down, making the floppily drive shaft assy to flop around, the various bits in the rear to load and unload, ad f'ing nauseum!!

 

AGAIN: Did you modify your rear LCA forward bushings?? (And if yes, HOW did you modify them.)

 

(If you answer yes I'm just glad I don't live where it gets that cold... no, I'm already glad of that. )

 

I have broken a rear diff and a rear axel. I am fully aware of the "PROBLEM" that we are discussing. It has cost me a lot of money and grief. Therefore, I set out to fix it. One by one the things I did reduced the problem. But it was not until my car sat on a rack for a couple weeks waiting on my IPT 5EAT that I had the wherewithall to really get to those rear LCA bushings, they are almost hidden. However, once I had them inserted and 3M polyed, and it sat there and hardened on the rack, the noise was gone. Once or twice, on a 0-60 timed run with a high brake torque launch there was an instantaneous thump along with the normal little squeal from the tires. That is all, and understandable since I don't intend to put steel inserts there for that Nth degree of traction. Excepting that extreme condition, not once, in any temperature, under any power or conditions have I had a suspension noise since the car came off the rack. (Other than when the rear axel went, of course.)

 

Trust me here. You don't have a different problem.

Edited December 12, 2008 by SeeeeeYa

[Guest]

Seeeya, there are NO LCA is in the rear. Please use correct term, it's confusing. The rear suspenction has trailing arms. LCA = lower control arm and is part of the front suspension.

[SeeeeeYa]

Seeeya, there are NO LCA is in the rear. Please use correct term, it's confusing. The rear suspenction has trailing arms. LCA = lower control arm and is part of the front suspension.

 

Whatever. NP. Just so everyone is on the same page . I know what it is, where it is, and what it does. Various people have had trouble labelling it... like now .

 

In the Vac Pics it is called "Rear Arm." All those pieces that have "link" attached to them are NOT the device with the bushings I'm referencing. In fact, in the Vac Pics, there is no mention of "trailing arms."

 

I have attached the .pdf. The arm we are discussing is item "#11, Rear arm." The bushing I speak about is "#13, Rear arm front bushing."

 

I hope this removes any ambiguity.

[Leonardo]

#23 on there I replaced with the Cusco rear power brace.

 

We need to get the bushing part number of the "suspension piece we shall not name" and cross reference it with ones from the STi and verify if there is an aftermarket version or a company willing to do it.

Edited December 12, 2008 by Leonardo

[LittleBlueGT]

you still have not said, definitively, that you have addressed the forward bushings in the rear LCA/trailing link/whatever!

 

The diff bushings are crap and have been taken care of satisfactorily.

 

 

AGAIN: Did you modify your rear LCA forward bushings?? (And if yes, HOW did you modify them.)

 

I was not aware that you did anything with these bushings. I must have missed it. Did you have a brief write-up on it anywhere?

 

I absolutely will do those bushings too. It isn't going to hurt anything.

 

Did you fill them with plastic first, then use the 3M stuff to fill in the cracks?

[LittleBlueGT]

#23 on there I replaced with the Cusco rear power brace.

 

Linky?

 

Did that do anything?

[SeeeeeYa]

I was not aware that you did anything with these bushings. I must have missed it. Did you have a brief write-up on it anywhere?

 

I absolutely will do those bushings too. It isn't going to hurt anything.

 

Did you fill them with plastic first, then use the 3M stuff to fill in the cracks?

 

Now I'm enthused . Yes, I spelled it out before, but it is obvious there is more ambiguity in the rear than there is in the front. When we all got front LCA poly bushings we were all on the same page. Not so on the rear.

 

In any case, I did exactly the same for those bushing as I did for my rear diff bushings. Since those nice inserts you used replaced my prototypical results perhaps they will fit those rear arm forward bushings, too? In any case, what I did was..... cut the PVC pipe sections to size, cover them in 3M WS poly and shove them into those bushing's air pockets, which had previously been swabed with the 3M poly, and then 3M poly squished and squished until front and rear of the bushing had been made contiguous. Then let dry for two or more days.....

 

I know you denegrate the 3M WS poly and I understand. But it bears remembering that I got the idea from a website that used it to recreate engine mounts..... that worked better than the originals. All jokes aside, the PCV inserts and 3M WS Poly makes on amazingly strong and firm bushing. If they are the same size, and not just general architecture, then those diff inserts would be a true blessing!