2000 GT-T Caldina RR(?) Knocking Noise... Getting Worse...

[rally 'rolla]

Hi,

As mentioned in the topic I have a 2000 GT-T Caldina with manual trans which has an increasinly bad knocking noise coming from what sounds like the right rear. The car is fitted with a factory larger rear muffler designed by TRD and made by some one else who I forget. It has done 129,000km and there are no modifications.

History:
I noticed it when I first purchased the car about 35,000km ago (obviously after it was too late to complain). It was only noticable under fairly hard driving conditions (a lot of on-boost time but no redlining, etc - just swift driving) heading out into the country. At first it would only make it while taking lefthand corners through a series of fairly tight corners uphill while engine braking (on the over-run if I'm right?).

It is a fast knocking noise that sounds fairly solid (not a tinie (sp?) noise). It is a bit hard to explain/put into words - sort of a br-dd-dd-dd-dd-dd (brrrrrrr while rolling your tongue ).

As time has gone on it has progressively and slowly got worse and now, 35,000km down the track it will make the noise on lefthand and righthand turns and occassionaly on the straight right after exiting a corner or corners.It still sounds like the right rear.

I have not noticed it when the car has been dead cold but then I don't push it until it has warmed up anyway so I'm not sure if that makes a difference.

I have asked my mechanic about wheel bearings and they said no but that it might be the exhaust hitting the drive shaft, however Left & Right turns cause this. Not just left turns which would push the exhaust to right and over towards the driveshaft. And there were no real marks on the exhaust to show signs of contact. I then asked Toyota to check during a service and they drew a blank and said all seemed fine.

I have read prevoius posts about it possibly being a wheel bearing however there is no droning, squeeking or other noise except the fast paced knock-knock-knock-knock-knock...

The shocks appear fine with no noted leaking etc.

Is it possible it is a diff problem? I hope not...

Sorry about the long description but I thought I would make it as detailed as possible.

Other than this the car handles well and smooth and noise free to drive.

Any help is greatly appreciated as I really enjoy driving this car and it has always been faithful, however this issue really concerns me and I do a lot of longer trips.

Thanks in advance for your help.

[RS13]

I had a similar issue with mine, turned out the swaybar attachment nut was loose. I had replaced the shock before I realised. I'd check that all nuts/bolts are tight on all components on the right rear suspension, as well as the condition of all the rubber bushings etc, make sure they haven't worn through and are contacting the bracket or chassis.

Oh, and a shock doesn't need to leak to be knackered.

[sidewz]

Is it worse when you come off the gas and are engine braking?

[rally 'rolla]

Cheers RS13 - I will have toyota take another look & specifically ask for those items to be looked at, after I have had a lok myself.

Sidewz: Yes. It is definitely worse while off the gas and/or engine braking. It doesn't seem to be there while I am accelerating. It is only very occassionaly apparant in a straight line and hard to recreate in this situation. Around corners I find it pretty obvious and not hard at all to 'recreate' (it basically will do it each time on a tightish corner so long as I am not being an absolute nana).

The only time I notice it around town is sometimes at roundabouts if I am pushing it a little, other than that it is really only on the open road.

Thanks for replying.

[cedwards]

not the same issue as sidewz is it?

[rally 'rolla]

I completely forgot to mention one thing...

After driving swiftly for about 30minutes and finishing with about 4-5km of uphill twisty stuff (which makes the noise got nuts) if I stop the car facing downhill and then reverse with a swift release of the clutch (not dropping the clutch!) it makes the noise also.

The revs have to be fairly high to have the noise appears and once it has started after a few bends it will make it on the straights, deaccelerating with the revs high.

If the revs are low the noise is not present that I have notice. I have wound down the windows to see if the noise is louder or more obvious but it is actually harder to hear it.

I will try and get under it soon.

I have read the thread sidewz started and and it is possible this is the cause - was a solution found?

[matty_j24]

mine had a clunking/knocking noise in the back the diff mounting bush was split.....possible another thing to look into

[rally 'rolla]

I've had a quick look underneath (in the fading daylight) and push & pulled a few bits and pieces and whatever this piece is rotated a few mm forwards and backwards (in relation to car orientation) which I'm sure can't be right!? The bushes (?) at each end appeared very soft.

http://usera.ImageCave.com/GEOFFatREMAX/DSC02207.JPG
http://usera.ImageCave.com/GEOFFatREMAX/DSC02205.JPG

Sorry, I don't know how to place pictures into the posts.

If this is not how it should be would it be enough to cause the knocking noise?

If not I'll keep hunting...

sidewz, I had a look at the relationship between the dampeners and the rear swaybar and the swaybar aligns with the centre of the angled part of the dampeners and there doesn't appear to be any markings that would indicate contact... But it was getting dark.

[johndoe1025]

if its doing it under reverse torquing things (eg overrun, reversing) then i would assume that it could be driveshaft play?

[99gtt]

check your exhaust if it is too close to the driveshaft or to close to the under body of the car. My blitz exhaust made a hell of a noise especially accelerating round corners

[jondee86]

Those appear to be the lower suspension links, and as such, they will
be subject to two types of loading. First they restrain the wheel assembly
laterally, transfering the sideways forces generated while cornering.

Second, they prevent the wheel from turning during acceleration or
braking. This means that they will see maximum loading either braking
or accelerating while turning.

If, as you have described, the knocking was first noticed while cornering,
I think the bushes in the lateral links would be the first ones that I would
inspect. They work pretty hard, and after 100,000 km they could be up
for replacement.

Cheers... jondee86

[rally 'rolla]

Thanks jondee86! That is very helpful.

Am I right in assuming that all of the bushes in those suspension links should be tight in all directions and that I shouldn't really be able to get any 'play' from the bushes or linkages?

[Mr Revhead]

they should be tight
but there will be rotational slack in them...
shouldnt be any side to side or up and down though
if you grap and twist, they should move a little, but only a coupla mm

[rally 'rolla]

Thank you Mr Revhead. The mystery continues as there is rotational slack (was very slack as it is very easy to rotate them that couple of mm).

I will have another look underneath today and try to see if I can locate anything else or make things move that shouldn't.

Keep the suggestions coming as I want this fixed ASAP.

Cheers!

[jondee86]

Am I right in assuming that all of the bushes in those suspension links
should be tight in all directions and that I shouldn't really be able to get
any 'play' from the bushes or linkages?

I am not familiar with those particular bushes. But if they are a typical
rubber in compression bush, I'd be very surprised if you could just grab
the strut with your bare hand and get it to rotate a few mm. Those bushes
are responsible for keeping your wheels aligned, and they can't do that
if they are soft/sloppy.

Try jacking the car up and grab the wheel at 9 o'clock and 3 o'clock.
See if you can get it to move on the bushings. If it does then the bushes
are poked, because on the road they will see far higher loads.

Cheers... jondee86

[Mr Revhead]

some of those bushs do have a little rotational play
and some cars (not many toyotas) they are a swivel type bush

[jondee86]

some of those bushs do have a little rotational play
and some cars (not many toyotas) they are a swivel type bush

Yup... don't doubt that for a moment Mr R You could use rod ends in
that situation and have links that were free to turn by hand.

I was just going by the fact that these links really only have to move in
a single vertical plane, so there would be no need for them to be able to
rotate about their longitudinal axis. Either way, the bushes have to be
able to resist the forces trying to "steer" the wheel.

Cheers... jondee86

[Mr Revhead]

yeah, i should have mentioned that it will take a little bit of grunt to move them, if you grab it lightly and twist is shouldnt move, if you give it heaps a little is ok. anything else and anything in another plane is not correct.
havea good look at them too, often you cant move them by hand, but driving forces place a lot more load on them than you will be able to, so if they look worn, deformed, cracked etc they are rooted

[rally 'rolla]

Cheers guys! That information really helps.

For your information it was a piece of cake to rotate that that suspension piece. I cold rotate it a couple of mm with just my thumb and forefinger.

I had a look at the bushes themselves and they don't appear to be split but they are looking quite worn.

After a couple of hundred kms in one stint yesterday I am convinced it is a suspension bush or diff mount as on rough roads (sealed but rutted) it makes the same noise in a straight line but no where near as loudly as when I go around corners...

Hopefully that is all it is as I imagine it would be a difficult/expensive fix?

[Mr Revhead]

the work itself is pretty easy
getting a bush maybe the hard part
i dont think theres on off the shelf kit, the part from toyota wont be dear, its just a matter of them having it