Vibrations under braking, before and after KADs

[Turbo_Steve]

Are your track-rod ends good? They're cheap and easy to replace, and I can't remember if you've done yours. Plus, you will DEFINITELY know your tracking is out once you've changed them

Other things to check:
Wheel hub face is perfectly level (steel ruler time - use the THIN edge! )
Hub bolts - stupid as it sounds, are these good and tight? Really? Are they in good condition? Are the holes round? Are the bolts the same on both sides of the car (I've seen one tapped and rethreaded, and the bolt used was fractionally too small)

Does the vibration come with noise, or does the car shimmy quietly?

I'd be tempted at this point to consider clamping off each caliper pipe and testing the brakes: at least you'll know which wheel to concentrate on.

BEWARE this should only be undertaken in a VERY wide open space with no one around....clamping off calipers is STUPIDLY dangerous if you're going to be using the brakes at any kind of speed, and criminally dangerous on the road.

[Beastlee]

Been back to the workshop since my last post. Have removed both discs and ensured both faces are clean and flat, there was minimal amounts of surface dirt on the inside of the bells. All bolts are tight and all appear to be the same size and shape per side. I can spin the front wheels without uneven resistance from the pads(with them still sat against the surface enough to need freeing off slightly in order to remove said caliper form the disc).
It was mentioned that there may be a torque difference across some of the bolts securing the disc to the bell housing. When we fitted them they were all torqued up and we also ensured a stress distribution pattern for tightening them. This may be a source of the problem though.

Have looked on Camskill's site and I can get rear discs and pads for £60 delivered so am tempted to do this despite the rears having been replaced by Mitsi just before I bought the car and having covered only 15K miles max. Possibly more wasted expense but it's a service item anyway and I am doing an 'all but the cambelt' service right now. At least it rules another item out.

Steve, was thinking how I could isolate the brakes, we have a large parade ground/car park next to the motor club that is deserted of a night time, this could be a possible method although I don't know how the ABS would take ot it. I do have the option of an MOT brake tester but doubt this would be good for the car even for a brief test, just enough to determine which axel it is.

I should point out that this only occurs at speeds in excess of 30mph, below this it's either not present or imperceptable. The vibration is not harsh as such but is easily felt through the wheel and passengers can occassionly pick up on it. It doesn't seem to be any worse at 70mph than at 30mph and can be created simply by lightly pressing the pedal. With a firm press of the pedal the effect is reduce and the car stops in a straight line very quickly. There is occassionally a flicker of the first AYC bar, I assume whilst it keeps the car straight with the weight shift, but I don't know if that's normal under very heavy braking on uprated kit. There are no vibrations when crusing, the discs/calipers/wheels are never particularly hot when I stop after a run and there are no obvious signs of issues on the rear.

I'm sorry if I've been going on with this, most people would probably live with it but it's annoying me and there's nobody here with an interest in cars like you guys.

Thanks again
Lee

[raph]

Just thinking about your clunk again.. check if the front left spring is broken? is the upper ball joint hitting the inside of the wing?

[Turbo_Steve]

Ohhhh it's sounding more and more like track-rod ends to me!

[raph]

^^but the track rod end would have to be seriously fecked to make a clunking noise..and he just had an alignment done.. the garage would have seen if the rod end had excessive play. .. the guy ajusting the tracking would have seen that the toe on the left side wouldnt stay put...

If it is indeed fecked and the garage didnt see it..that would be a reminder never to go back there again.

[shaun1978]

Do you just feel it through the steering wheel or through the brake pedal as well?
Could you not throw a beer or two in the way of one of the LAD guys on one of the camps?
How are the shocks and springs , it could be that they are knackered and reverberating under braking.....
Just trying to think of solutions....

[Beastlee]

Steve/Raph, How about track rod inners? The outers seem fine but I'm thinking the inners could be an issue given what symptoms I have. The guys doing the tracking yesterday only spent about 1 minute adjusting the steering and were distracted even then. It's possible it wasn't perceptible as the wheel was straight. There's definitel no noise when in a stright line but it seems to only be with the wheel at approx 45deg left.

Shaun, have checked the shocks ad springs a couple of times as the car has always been pretty firm for stock kit. No evidence of cracked/broken springs or any leaks on the shocks. The current motorclub manager is a time served REME vehicle tech and he can't find anything either.

Definitely tempted with replaceing the rears, I've replaced everything else as it is so why not? Will price up the inner track-rod arms too and may as well do the outers at the same time.

[Kenneth]

Inner rack ends are definitely worth a look. Just recently had to replace both of them in the Legnum. We went through the front tyres (from being in perfect condition to down to the canvas on the inner edge one side) very quickly (a couple of months of fairly low use)

[raph]

well.. i guess you could do em and get the alignment done again afterwards.

Have you checked the upper wishbone? any tell tale marks on the inner wing?

Its so difficult to diagnose noises over the phone let alone the internet

the inner track rods (if the same as GDI/V6) are available through any parts store.. last time i checked 30ish euro (GDI)

[Beastlee]

Raph, definitely no impacting going on under there, there's a coating of muck on evcerything and definitely no disturbance of it. The noise is definitely something rattling in situ rather than a contact noise.

Kenneth, I've done less than 15k miles since I bought the car in Sept 07 and it was July 08 when the wheels were fitted. I reckon the wheels have only done 5-6000k miles at most and the inner edges are considerably worn.

I think I'll try and get to the inner rods, I've priced up the full inner/outer/boot set and it will be £90 for me. Will get the garage to fit as I wouldn't want to fit and drive without the tracking being done.

[Beastlee]

I've not done much on this TBH as I'm slowly losing faith in the car. I did however get to do some driving above 40mph for the first time in months at the weekend.
I can confirm that below 40mph there is absolutely no vibration, you just wouldn't know there was an issue. Between 40 and 50mph the whole car shakes enough that everyone in it can feel it and above 50mph there's a very slight feeling through the wheel and brake pedal but no shaking of the car. Unfortunately it seems that the worst of it is at the speed I travel at most of the time.
Incidentally I started getting my ABS/TCS/Skiddy lights on whilst driving on Tuesday. Checked the brake fluid level which was barely below Max but I noticed the level switch was touching the bottom of the filter tray. I think the switch has come apart and now it only needs a suitable bump in the road to trigger the low fluid warning. I'll have to drain the resevoir and see if I can sort it.

[peter thomson]

Have you looked at the driveshafts and prop lee. The whole car shaking may be the sign of a damaged joint rather than a brake problem

[Beastlee]

Peter, would that not mainfest itself during acceleration or other times? When I'm not applying the brake at 40-50 the car is as smooth as can be at all speeds, it's is a really nice drive TBH. Whenever I've been under there neither seems to have any issues and there's no excess play in anything. I'm happy to reckeck it though.

[peter thomson]

I had a vibration issue as well but at a steady speed rather than under acceleration. Seems it could depend on the load on a componet when this occurs. The prop joints may not be loose but the joints could be dry . This could make them very tight rather than have play .Something that is easier to check with them removed rather than on the car.
I know it's difficult that you don't have anybody near that you can swap parts out to check but you will find the problem in the end

[steelie600]

inner cv joints, it did it on mine!!!!

regrease them an youll be fine

[Beastlee]

OK, new issue. The ABS light coming on is now doing it all of the time and it wasn't fluid. Have read the TCS codes which are 41, 43 and 44

41 FR solenoid valve systematic
43 RR solenoid valve systematic
44 RL solenoid valve systematic

It's fine until you get on boost the first time then the lights are on. I floored it in first earlier and the AYC went ballistic as the TCS dropped out. I have two nice black marks along the road that show how far I travel in 1st before 6500RPM

I'm going to re-bleed the complete system and get the rear brakes replaced but I'm sure the codes refer to the valves in the ABS block which worries me.

ANyone want ot buy a modified VR-4?

[Beastlee]

OK, so this is looking like a vacuum hose issue. Bled the brakes for the 15th time since November and it still made no difference, even with an ECU reset! Within 2-3 minutes of driving the lights came on as I shifted into 3rd gear with minimal throttle. Having read some TCS fault threads I checked something out....I only have wastegate pressure (0.5bar max) again. On the return journey from the car wash I couldn't trigger the lights no matter what I did. Looks like it's time to order a load of vacuum tubing as well.
Checked out the rear brakes and they seem perfectly fine as did everything else I looked at on the bloody thing. Only thing I noticed is there's a relay/solenoid going a bit wacky when the car is idling.

[Beastlee]

OK, so I know you're all bored of me and my problems now but I think I've at least found part of my problem. I mentioned in another thread of Brad's that I too had funny power issues, ie. when opening my doors, etc the head-unit would reset and the lights flicker. Wel I've now found that it's happeneing as I drive along and at exactly the same time the lights on the dash come on. I'm now certain this is purely an electrical issue and it's compounded by a separate vacuum issue.
The other odd thing is that when I switch my headlights on I cn't guarantee that both HIDs will comeo n every time. I have to switch them on and off a few times to get them on together. I had put this down to a faulty light switch but I now believe I have an earthing issue somewhere. I have the wire I just need some decent sized ring terminals so I can make up an earth bonding kit.

[MarkSanne]

Electrical bugs.... me don't like those! Proper earthing could solve it, but then again.... if not, then where to start as such intermittent faults are bloody hard to find. Hope you'll find it fast Lee!

[Turbo_Steve]

Hmmmmmmm..... IIRC the earth points are down next to your feet behind the covers?

Lee.....before you start hunting for a bad earth, it may be worth having a good look at your battery terminals.