Audi A4 (B7 3.2) steering shake

Started by Imraan Ali, November 19, 2017, 08:32:09 AM

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Imraan Ali

Hi new member

Needed some help with my Audi A4

I have a steering shake between 80-100km. Steering and front seats and even rear seats shake. Have done wheel alignment, wheel balance, rotated tyres, new shocks, New control arm bushes, New tyres and problem still is not going away. Super frustrating. All of the above is due to going to various workshops who have advised me to replace all the above. Serious $$$ spent and its still there. Audi told me slight bent in my wheels but arrow wheels said they are fine  :( :(.

Need some advice please guys and can I borrow some wheels for couple of hours to test if my wheels are truly stuffed??

Help please

the phantom

Land Transport New Zealand, taking the fun out of driving since August 2008

80 Vert

2010 T5 Transporter TDI  Tuned by Superior Tuning NZ
2003 Jetta Coupe soon to be R36TT
1991 Golf GTI 2.0 TSI swapped
1963 Type 34 Karmann Ghia, turbo 2.0
1990 Porsche 964 911 Carrera 4
1980 1303 Beetle vert, under restoration

Imraan Ali

Okay will check them again. Apparently Audi checked them and said no issues but will get them seen to again. Thanks

sfkarl

I'm getting a similar vibration in my B6 A4. I haven't gone through the checklist of obvious faults yet, but this advice is good to know.

Planning to -
- balance the wheels
- check wheels for buckles
- check steering alignment
- inspect suspension components
- check for warped brake rotors
and also
- inner CV joints

kiwihigh

Aftermarket wheels? maybe missing locating hubcentric rings.
BUILT not bought

DTM

Quote from: kiwihigh on November 21, 2017, 11:31:09 AM
Aftermarket wheels? maybe missing locating hubcentric rings.
I was thinking the same thing Even if they were all there they could be the wrong size fitted which happened to me many many years ago.

the phantom

Land Transport New Zealand, taking the fun out of driving since August 2008

sfkarl

So after some more driving I'm quite sure its the brakes seizing up. It's fine when cold, but after about 10km a shudder begins and builds quite strong. It is significantly worse if the brakes are applied.

The fuel economy takes a dive, the engine feels laboured. I have pulled over and all of the brake rotors are hot. Damn hot. Front left sizzling hot.

It's not just 1 seized caliper. I think the vent hole in the brake master cylinder is blocked, allowing pressure to build in the whole brake system and engaging the brakes. Which heats up the brake fluid and increases the pressure even more.

The rotors are in good condition but are possibly warped now. No telltale wear indicating a seized caliper.

I unplugged the ABS pump to test if that had anything to do with it. Made no difference. I also checked the brake fluid level in the reservoir to see if it had been overfilled. No fill line is on the reservoir and there was space in there. I loosen the cap to be sure it wasn't pressure building up in the reservoir itself. No effect.

So plan now is to remove and clean the master cylinder. I don't think there is anything wrong with the seals. I think its a blocked vent port possibly from dirty fluid being used. I think this because all 4 brakes are effected.

What say you?

Gordo

I would say a very good chance you have hit the nail on the head - bit late responding but sometimes you can use a straightened paperclip to clear the relief/replentishment port.
When replacing master cylinders, it is possible to run into a problem with the new cylinder being slightly different in the pushrod length and not exposing the port* when brakes released - was caught by that on a Land Cruiser as an apprentice.

*As an aside, with care, you may be able to ride yourself of an over-long slack pedal by judicious use of spacers to minimise the piston travel after the port is exposed - after making sure there isn't excessive play elsewhere.
These are my thoughts and opinions - sometimes I'm wrong, but not often ;-)

sfkarl

Thanks. I haven't gotten to this job yet. Have been working on other more important tasks but will report back here when I do.

sfkarl

So I've replaced the brake master cylinder with a new one (TWR brand which I think is fine). I then bled the entire brake system.
I replaced with new as the circlip holding the original one together has no "eyes" on it to get a pair of circlip pliers onto. I assume they don't want you in there servicing the item.

The brakes are solid in terms of their function, but the problem has completely gone away. There isn't the terrible wobble at speed but it is slightly detectable and it's not a wheel balance issue as it comes and goes at the same speed.

I'm planning to "run in" the new configuration to see it will settle and bed in, but there's still a lot of heat in the brake discs even when the brakes have done no work, and car feels laboured to me, like it can't just roll on.

Next thing to check is the brake rotors for warpage and runout with a dial indicator. If it's not that, then could be (slightly) seized calipers.

sfkarl

Done a few long trips in this car and brakes are working a lot better now. Seemed to come right after a bit of driving.
Getting around 12km/litre fuel economy at highway speeds which is pretty reasonable for 3.0 V6 I think.

sfkarl

So after it all working pretty well, I used this car to tow a trailer. A car transport trailer. With a Honda H-RV on it. Then with a Range Rover on it. Then another Range Rover. I hired a trailer and transported 3 wrecked cars in one day.

Ironically, the car that should have been pulling the trailer, my working Range Rover, was not road legal, because it needs parts from one of the Range Rovers I was towing...

And now the issue is back with the Audi. A sort of slippy/shudder which is most noticeable when torque is being applied. ie driving uphill. It feels like a wobble, like a wheel is out of balance or out of round. I assumed this was from the brakes dragging because the rotors were always really hot. So I replaced the brake master cylinder and flushed the brake lines and the rotors and brakes are really good now. Right temperature consistent with brake usage. It seems that was just coincidental.

So a shudder that comes and goes at various speeds, is not engine side (there is no vibration if the car is parked and the engine reved) and if when driving I feel the judder and knock the trans into neutral the judder continues unchanged, then it is on the drive side and will be either:

a) half shafts or prop shaft or wheel imbalance or out of round (I don't think it's this because it occurs at different road speeds)
b) or CV joints (could be worn cups or bearings slapping around between acceleration and engine braking)
c) engine or transmission mounts worn which hit weird frequencies at random speeds and set up a resonating "wobble"
d) slipping clutch pack inside the transmission (please no)

What do y'all be thinking?

Gordo

I don't think it will apply in your case, but it may be of interest to some.
I recently replaced the driveshafts on the shopping basket*. I had a fair bit of trouble sourcing them and the ones I got are less than well made with some light binding evident under driving and over-run torque that feels like a loose wheel or a 4x4 with a locked centre diff'. I took them off to relieve the tight spots but they were of a non-servicable design - seem to be slowly burnishing themselves into a bit more smoothness over a couple of hundred km of town driving, so putting off trying to re-source replacements for now.

*Older, non-VAG vehicle.
These are my thoughts and opinions - sometimes I'm wrong, but not often ;-)

sfkarl

Yeah, I did suspect a partially bound diff but forgot to mention it in my previous post. The car is Quattro awd so there should be 3 diffs.

On a couple of occasions I thought I could hear and feel tyre scrubbing on very tight turns in the carpark. But when I tried to replicate it the issue was gone. More testing required.

How to best check the condition of the CVs? Lift the car and see if they rattle when you roll the wheel forward and back?

Anyone know the diff types for a B6 3.0 quattro? I'd say the front and rear diffs are probably just open type but what about the center diff?

sk

Imraan Ali

Hi the issue was the aftermarket wheels which was a replica wheels. When we put the Audi original rims back on there the issue was gone. My car didn?t like and spacers etc. factory wheel fixed the issue

sfkarl


Imraan Ali

Hi buddy car fixed and sold now. I have a S4 B8 chassis loving it

sfkarl

The wobble returned and after a lot of dicking around it turned out to be a faulty brake vacuum booster. Replaced with used item and the binding brakes are now finally gone.