C63 Judder

[thebig1]

Hi Guys,

New C63 owner, yes pics appearing soon when weather permits.
Just detailed the car, took me three days lol.
What can I say about this car, WOWWWWWW
I am not new to powerful cars etc but this car is amazing.

One small issue I noticed, maybe something and nothing.

When I come to a slow stop, when I get to say 2 or 3 mph, the car feels like its juddering slightly. Like brake pads juddering. Then as I pull away slowly, same feel for 2 - 3 mph then all fine.
Not wheel balance, way to slow a speed for that so I am guessing front pads?

Car is a 63 plate c63 and has done 10K miles.

 

[kamalpatel12448]

Congrats! Sorry to hear about your trouble, never seen or heard of this before, but lot's of owners here so I'm sure someone will come along shortly.
Kamal

 

[Felstmiester]

It would only be anything to do with pads/brakes if your on the brakes at the time. And pulling away at 2/3mph your not gonna be braking. I would say more likely a defective tyre. Maybe a bump on the tread or something? Also the standard wheels are prone to cracking or bending straddling speed bumps so don't rule out wheel balancing.

 

[thebig1]

Hi,

Just makes me think that only appears when foot brake is applied and from what I read, brakes are automaticly applid unti a certin spead for roll back. Its through the pedal too, not through the streering wheel which a balance would feel like.

 

[developer]

Does it have an LSD - they can make the car a little unrefined at low speeds?

Also, as it's under warranty, I'd drop it into a dealer.

 

[HollowPoint]

At a guess, I'd go with a slightly warped/rippled disc, at some point it's probably been a little over-cooked and you're only feeling it at very low speeds. I doubt it'd be a tyre, or wheel balance at that speed, as you say, it's too slow to feel it and it would get worse as you accelerated, not better/smoother. Another possibility is the gearbox, it could be that at slow speeds, the box is miss-behaving.

I know next to nothing about the C63, other than I was admiring one at the dealership I bought my car from on Saturday and of course someone might pop up with knowledge of a known fault, I'm simply offering some suggestions based on general mechanical knowledge/experience.

 

[Felstmiester]

Hi,

Just makes me think that only appears when foot brake is applied and from what I read, brakes are automaticly applid unti a certin spead for roll back. Its through the pedal too, not through the streering wheel which a balance would feel like.

I wasn't aware of the brakes being applied automatically . If this is the case it's most def the disc/discs. On my van I've had a lump on the tyre on two occasions and you can only feel it at very low speeds. Once the speed is built up the suspension takes the wobble away if you know what I mean.

 

[thebig1]

Cheers guys, I will pop it in to a dealer after the holidays to get it looked at.

 

[st13phil]

Is it originating from the brakes or the drivetrain?

My W212 exhibited a slight judder while creeping in traffic at slow speed if I was dragging the brakes gently to match the speed of the traffic. It was a faulty wet startup clutch (the bit that replaces the torque converter on the MCT transmissions), and was replaced under warranty.

If you're uncertain, at around 20mph knock the transmission into neutral and gently brake to a halt. If if still judders it's the brakes, if it doesn't it's more than likely the wet startup clutch.

 

[thebig1]

hi,

Thanks for that, I will try it at dinner time on my way home!

 

[st13phil]

When you try it, another giveaway is that the vibration frequency will vary with road speed if its brakes, whereas if its the wet startup clutch the vibration (assuming that you don't touch the throttle) will be at a constant frequency but will reduce in intensity as the car gets up to its natural creep speed with the brakes off.

 

[thebig1]

Cheers I will try it. I think it was in line with speed of the car, not engine but will check.
A guy here mentioned that some Mercs have addaptive brakes where the brakes are applied very slightly to keep the discs clean and dry and it operates at low speed?

 

[Ricky16]

I get a judder when coming out of reverse into drive lasts about 2 seconds it's as if the gearbox hasn't caught the gear correctly

 

[st13phil]

A guy here mentioned that some Mercs have addaptive brakes where the brakes are applied very slightly to keep the discs clean and dry and it operates at low speed?

Not that I'm aware of. They do have brake priming and drying, which automatically causes the pads to kiss the disks, but this only happens in wet conditions.

 

[thebig1]

Hi ya, I just tried it, rolling in Neutral it disappears. If then engage drive and let the car creep, it's back. If I have the parking brake on, put in drive and release the parking brake, it's still there

 

[st13phil]

Hi ya, I just tried it, rolling in Neutral it disappears.

So, if I've interpreted correctly, rolling in neutral (at low speed with the brakes lightly applied?), there's no judder?

If then engage drive and let the car creep, it's back.

Is that with the brakes applied or not? And did you let the car creep up to it's "normal", i.e. fastest creep speed on flat road? Did the judder then disappear?

If I have the parking brake on, put in drive and release the parking brake, it's still there

OK, the parking brake is mechanical and operates on shoes in the rear disks, so that doesn't tell us anything.

 

[thebig1]

Hi, if I slow to a stop using foot brake in neutral, no judder.
If I slow to a stop in drive, slight judder.
If I let off either foot brake or park brake and let the car creep, judder until the car is at its top creeping speed, say 4kmh or above and the judder goes

 

[st13phil]

OK, from your description I'd be pretty confident that your car has the same issue my E63 did with the wet startup clutch. Fortunately, the warranty should cover it.

 

[thebig1]

Hi ya,
It's going in on the second of Jan. Is it a big job?
Not good when car is one year old and only done 10k miles

 

[st13phil]

It's a transmission out exercise. Probably between half a day and a day's work.