ilike2eatricers

I installed my K2RD coilovers on Friday without the rear camber (couldnt find it) adjuster there were no sounds. I got an allignment yesterday but since I couldnt find the rear camber adjuster they couldnt adjust it during the allignment. I ended up with -3.1 degrees of negative camber in the rear and needed to get closer to -1.2 to -1.5.

So last night I installed the rear camber adjust which is a one piece lateral adjustment (that installs next to the differential on the driversides). I lowered the subframe a little and installed the link and tightened everything up. It looks like there is less negative camber than before, but after installing this I hear a very loud "whirring" sound that appears to either be coming from my diff or my driveshaft when accelerating or on decel even in neutral. It does not make any noise when I am maintaining speed. I checked to see if anything was rubbing under the car and nothing was. I also drove the car with the rear jacked up in the air and the sound was still there but I couldnt for sure say if it was the diff or the driveshaft. I will be getting it alligned very soon but am not sure if this is a normal effect. I dont think it sounds very normal at all. Other than the sound it drives normal but I have yet to push the car since I am still breaking in the engine.

Insights?

ilike2eatricers

I should also note that I have already changed the diff fluid with redline about 2-3 months ago.

GTU_FAN

I dunno about that kind of camber adjuster since I use the mazdatrix units but after I installed my rear steer elliminators I've got a lot more humming/whirring noise comming from the rear end.

ilike2eatricers

Interesting... How much camber did you have in the rear? My whirring is pretty loud, comparable to the loudness of my turbo spooling, maybe even louder.

EDIT: I did some search and realized I have the rear camber adjuster from mazdatrix. I bought my k2rd coilover kit used.

"Rear Camber Adjuster (Left and Right threaded - allows adjustment without removing)"

ilike2eatricers

Bump

Drove it to work today and now the sound is only happening when moving from a stop and slightly in second gear. Did everything just need time to set into place or something?

vaughnc

Check tranny & diff fluid levels. Make sure the pads aren't dragging. Make sure the brake pad separator springs are installed. Make sure your wheels are on tight. Check the wheels sprin freely & don't make any noise while up in the air.

mr_vaughn

iTrader: (1)

i had the same issue after installing my rear camber adjustment .

i figured it was the sub frame touching the body/frame of the car and the vibrations of the drive shaft coming through the touching.

Also mine was only on accecl. or suspension movment when the suspension was push down from the power applied or road conditions.

try increasing the negative camber and see if the issue goes away?
also what is the drop on you coil overs? also try and decrease that number?

i have been looking for rear strut tower adjustment plates but have not found any.

SureShot

I know you looked - but I'll bet somewhere there is a spot of the plastic fender liner rubbing on the tire.

BTDT

ilike2eatricers

Both tranny and diff fluids were changed recently with redlineand nothing has been leaking so I dont think that is the issue. I did turn the rear wheels in the air manually and there wasnt that sound.

I'm glad I'm not the only one with this problem.

When I brought my car to get alligned without the rear camber adjuster they said I had -3.1 degrees of camber on both sides. They said I should try and get closer to -1.2 degrees. I eyeballed the -3.0 degrees camber and kept reference to that when I installed the rear camber adjustor and lengthened it to get the wheels closer to 90 degrees with the ground. It looked less than -3.0 so I figured I was closer to what I should be. So are you suggestion I raise the car and go farther negative on my camber settings?

I'm not too sure how much I lowered it honestly. It has sleeved threaded perches and I just lowered them so I have about 2 finger width between fender and tire with my tire/rim setup in my sig.

GTU_FAN

My whirring isn't that loud, its just a thrum you can hear at highway speeds. I had about 5 degrees or so of negative camber after I lowered it. I got the camber links to solve that problem.

ilike2eatricers

Someone suggested to me that the diff mount may be hitting the floor board. I'll check that out. Any other ideas or experiences out there?

I'm not sure if I should just bring it to the allignment shop again and let them deal with it or try and adjust it myself first and see if it fixes the problem. The thing is I have a feeling they will adjust the camber link anyway when they redo the allignment.

JumpyRoo

For one thing, I can tell you all that none of you can eyeball camber. Or any alignment angle. As for the rubbing, take it in for a complete inspection, noting the problem, and a new alignment. When I do an alignment, it's only in the shop, and it's within a hundredth of a degree dictated to me by a laser measuring machine, not a tenth of a degree, certainly not a whole degree. This comes down to a live measurement taken as I move threaded elements 1/128 of a turn, or edge a subframe member half a mm. Not something you can do in your garage.

Furthermore, if you do take it to any kind of self respecting alignment shop, you can get the alignment, and continue taking the car back for free until the noise goes away, because then they will have "assumed responsibility for the problem."

ilike2eatricers

Thanks for a more detailed explanation. I had already planned on getting it realligned since I have a one year plan, but wanted to see if I could actually fix the problem myself first.

ilike2eatricers

Dropped it off at the allignment shop today and they said that the car was too low causing the halfshafts to be too far from the stock angle. They called me and told me to pick it up and raise the car higher and bring it back.

They said the whirring sound I hear sounds like my differential is going out because it is load sensitive. Diff was fine before I put in the rear camber link.

BS or truth? Honestly I dont know too much about the driveshaft, halfshafts, and how the diff are located in relation to one another or how they affect each other.

Dan H

https://www.rx7club.com/showthread.p...ght=halfshafts

I have a hunch from reading that thread but maybe try stiffening up the rear a lot on the coilovers and see if the whirring sound goes away somewhat. This will give it less rear end squat on acceleration since you said the whirring sound only comes from a standing stop. I'm thinking because of the squatting and the extreme angle of the halfshafts on accelerating, its putting stress on something until you maintain a constant speed when the drivetrain starts to settle.

How is the diff mount too?

Let me know if you want me to check it out too. Or you can maybe talk to Dave about the rear end setup.

ilike2eatricers

Thanks for the link Dan. I tried calling Dave just about 10 minutes ago but he didnt pick up. Probably busy as usualy.

My diff mount is fine, checked it the other night. The rears are set on 6/8 on stiffness, I will adjust them to full stiffness.

Anyways, the allignment shop called me and told me to pick up the car. They said it was too low and told me to raise it up an inch. I have them dropped right now 2 finger widths between the tire and fender lip. They said they shortened the link as much as they could to get closer to -1.0 degrees camber that I wanted and said I need to raise the car up higher.

The whirring sound is now in all gear at all times when the wheels are rotating. This is really pissing me off. When I get home I'm going to raise the car up an inch and put on the RB camber link that was on there before that I havent adjusted. I hope there isnt any permanent damage down to the diff, driveshaft, half shafts or cv boots. I noted this to the guys at Wheelworks before I left.

Also they boosted my car to 0.6 bar while I'm still breaking it in.... I even showed them my peak hold function and they just avoided it. I even told them I put in a new engine and was still breaking it in but they compared my car to a new subaru which is boosting right off the lot. They also told me my check engine light went off but when I drove it didnt pop up at all. I need to pull codes also just to make sure. I'm SOOOOO pissed off right now.

Dan H

Damn, which Wheelworks is this? I just changed the tires on my other car at the one on Ocean St. and was going to have them do my FC in the future. But now I won't. I'd give them some crap about the boosting thing but thats just me.

Anyways, keep us updated on how its coming along.

ilike2eatricers

It was the wheelworks on ocean. Justin recommended that Carlos do it so I let him. Anyways he seemed like a really cool guy and explained alot to me but when I checked my peak hold function I got soo pissed off. I hope nothing bad comes out of it. Too bad my safc couldnt record highest rpm reached after the car was shut off. He said he only went up to 3k but somehow built .6 bar (8-9 psi) by then with my severely ported wg.

I'll be wrenching on the car tonight. I'm paranoid to let anybody work on my car without me being there and this only reinforces that paranoia. Too bad I dont know how to do allignments myself or have the equipment.

RETed

It could be something; it could be nothing.
When I did my car, I didn't notice any noises, but my exhuast is kinda loud.
The rear subframe uses a lot of rubber isolation bushings for noise control, and it could be you're hearing noises the old rubber bushings damped before.

If the noises are vehicle speed dependent, it can only be the driveshaft, rear diff, axles, or hub bearings - or combination of any or all of them.

I would try and check the u-joints on the driveshaft first, as this is pretty easy to do if you can get under the car (i.e. vehicle lift).
Remove the rear of the driveshaft from the rear diff by removing the 4 bolts.
The end should come loose.
Check the rear u-joing for grinding by hand.

If that passes, check the rear axles.
Grab the axles and shake them as hard as you can.
They should not move at all.
If one of the shakes, it might need replacing.
Inpect the CV boots also for leaking.

Spin the rear wheels by hand - does it make load groaning sounds?
If it does, the bearings might bad.
Grab the tires and shake them in and out alternately, first top and bottom and then the two sides - there should be NO play.

BTW, what kinda Redline fluid did you use in the rear diff?


-Ted

ilike2eatricers

Thanks for the reply Ted.

I inspected the U joints and driveshaft and they checked out fine. Axles checked out as well. CV boots not torn or leaking and wheel bearings dont groan.

Anyways since the allignment shop maxed out the camber adjuster (shortening it to reduce negative camber) I raised the car about an inch and then lengthened the link until I didnt hear the sound anymore. It might have been a combination of the car being too low and the link not being able to compensate enough with the drop. I think part of the differential output shaft (?), the part between the diff and driveshaft was rubbing on the inside of the subframe under certain load.

Right now the top of my rear wheels are tucked into the fender (positive camber right?) I cant shorten the link anymore to get to the -1 degrees camber that I would like without having the output shaft hit the subframe again.

So what options do I have? Raise the car higher? Get 2 other camber links for the left and right side?

BTW I used 75w90 for the diff I believe and mt90 for the tranny.

RETed

Wheels tucked at the top is negative camber.

Yeah, you could be right.
If you drop the car low enough, the rear subframe starts to ride on the crossmember.
Check the pair of front links - make sure they do not contact the crossmember - if they do, you need to raise it.
Did the rear "thunk" when you hit a bump?
If so, the rear is too low.

No, getting the front pair of links will not help you anymore.
If the rear camber is still too much, you need to raise the car more.


-Ted

ilike2eatricers

Ok thanks for the quick response. I did get an ocassional thunk sound on bumps. Guess I will have to raise the car a little higher. Anyways how to people who really drop there cars deal with the subframe rubbing issue?

RETed

They are crazy to drop the car that low.
It induces crazy negative camber, as you have found out.
It is next to impossible to dial out all that excessive negative camber, and it quickly eats tires in literally weeks.


-Ted

Hot_Dog

This type of link does not provide any vibration isolation, since it does'nt contain any rubber bushings. Mazdatrix also sells a rear camber adjustment link with rubber bushings, but it requires removing one end to adjust. I've used both types of these links, and have had a similar problem when using the link without rubber bushings.

Hot_Dog
90 RX7 GXL
02 Acura RSX-S

ilike2eatricers

I actually have a RB one also that is remove type as well, almost exactly the same as mazdatrix's but doesnt have rubber bushings. I like the one pictured above better.