Clunk on foot down acceleration.

[CrustyClam]

I feel an issue is developing and just wanted some advice on what's it's likely to be and what you would do.

On three occasions when I've put my foot down I have experienced a pause during the acceleration, followed by a very harsh lurch/clunk sound. (Within a couple of weeks)

I used my icarsoft v2 to check TCU and no codes are showing.

Looking online (and chatting to someone on a Facebook group for ML63 owners), I wonder if I could have a faulty transmission solenoid (or multiple).

Undoubtably I will take it my local Indy for them to check but was wondering if solenoids are culprit, would it be cost effective to have a conductor plate refurbished before refitting ( if that options available).


Thx

 

[brianbrian]

What's the mileage on the car concerned.

 

[AMGeed]

Have your transmission and engine mounts checked.

 

[M80]

Have your transmission and engine mounts checked.

That wouldn't explain the pause.
What mileage was the ATF last changed.
You don't recon a conductoir plate you just replace it, approx £100 for the part.
You would need someone who understands the specific purpose of the solenoids, or you might end up changing 6 I think.

Star might show more info.

 

[Flyinspanner]

What’s the mileage?
Have you ever had ATF changed, it could be a valve in the tranny is a bit slow to operate.
Clean atf may help if it’s been in there forever?

 

[CrustyClam]

What's the mileage on the car concerned.

63k

 

[CrustyClam]

That wouldn't explain the pause.
What mileage was the ATF last changed.
You don't recon a conductoir plate you just replace it, approx £100 for the part.
You would need someone who understands the specific purpose of the solenoids, or you might end up changing 6 I think.

Star might show more info.

ATF changed at about 59k, first thing I had done when I bought it.

 

[CrustyClam]

Have your transmission and engine mounts checked.

Must admit that never though of that

 

[LostKiwi]

I'd also be checking transmission fluid levels.

 

[CrustyClam]

Thanks for the replies. I've managed to get the car booked in for a diagnosis next Wednesday. Don't want the situation to get any worse, and cause damage that could have been avoided.

Will update once I know more

 

[mercmancdi]

Thanks for the replies. I've managed to get the car booked in for a diagnosis next Wednesday. Don't want the situation to get any worse, and cause damage that could have been avoided.

Will update once I know more

Does it happen when you pull from D into R. Or when just taking off ,or is it just while already moving.

 

[CrustyClam]

Does it happen when you pull from D into R. Or when just taking off ,or is it just while already moving.

Only noticed when moving. I just had a look at my dash cam footage when it happened yesterday, was joining the motorway at around 40mph, foot down to overtake and that's when it happened.

 

[mercmancdi]

Only noticed when moving. I just had a look at my dash cam footage when it happened yesterday, was joining the motorway at around 40mph, foot down to overtake and that's when it happened.

That probably rules out prop shaft .
Looks like you would need as said a run on star first , cheaper than starting to change parts etc.

I had similar but did not happen much while driving mine was a drag when taking of and s thump when pulling from D into R it was mostly in my prop shaft
and a gearbox flush while getting sorted.

 

[M80]

A thought,
check for worn bushes at the rear axle, specifically the centre A frame bush.
This still doesn't explain any delay though.

 

[CrustyClam]

That probably rules out prop shaft .
Looks like you would need as said a run on star first , cheaper than starting to change parts etc.

I had similar but did not happen much while driving mine was a drag when taking of and s thump when pulling from D into R it was mostly in my prop shaft
and a gearbox flush while getting sorted.

Ideal world would be be ATF topup, but Jonah is my middle name (well it should have been). Failing that keeping fingers crossed star will show something. If it's conducter plate / solenoids then not so bad.
Praying it's not the mechanics of the transmission.

 

[CrustyClam]

A thought,
check for worn bushes at the rear axle, specifically the centre A frame bush.
This still doesn't explain any delay though.

Presuming ok. I had a health check from Mercedes at the end of Jan, nothing to report.

It's a harsh delay, you really feel the clunk.

 

[alexanderfoti]

+1 on the mounts. Most likely cause.

 

[CrustyClam]

+1 on the mounts. Most likely cause.

Thanks. Is replacement a labour intensive job? Assuming engine needs lifting to replace.

 

[alexanderfoti]

Approx 2 hours Inc gearbox mounting. Engine can be supported from underneath.

 

[CrustyClam]

Approx 2 hours Inc gearbox mounting. Engine can be supported from underneath.

Cheers, that's not as bad as I thought.