CriticalCommonTransmission

Mercedes-Benz B-Class: Autotronic CVT (722.8) shudder, jerking and failure (W245)

Autotronic CVT (722.8) shudder, jerking and failure (W245) is a common transmission fault on the Mercedes-Benz B-Class on the 2005–2011 cars, and we rate it critical. Putting it right costs $4,000 to $8,000 at New Zealand independent workshop rates. Below is what goes wrong, the symptoms to notice on a test drive, where to look, and what to ask the seller before you hand over any money. It is one of 8 documented faults on the Mercedes-Benz B-Class.

Vehicle: Mercedes-Benz B-Class
Years: 2005–2011
Fuel: petrol
Gearbox: cvt
System: Transmission

This page covers the Mercedes-Benz B-Class as a model. Some faults only affect particular engines or build years — enter a plate below to narrow the list to one car.

All Mercedes-Benz B-Class faults8 documented faults on this model

What you are looking at

No photograph available

We do not hold a verified photograph for this fault yet. We would rather show none than show a picture of something else.

What goes wrong

The first-generation B-Class shares the A-Class's Autotronic continuously variable transmission, and it is the generation's most expensive weak point. The belt/pulley pack and its electrohydraulic control unit wear out, causing shudder pulling away, hesitation, flaring revs and eventually limp mode or no drive. Mercedes treated the fluid as 'sealed for life', which accelerated wear, so a car with no CVT fluid history is higher risk. A rebuild or replacement usually costs more than a tidy W245 is worth.

What you would notice

Shudder or juddering when pulling away
Revs rise but speed does not follow
Hesitation or jerk when accelerating from a stop
Transmission warning symbol on the dash
Slips into limp mode on a longer test drive

How to check it

Where to look. Transmission, mounted transversely behind the engine under the front floor

Test drive from cold and again after 15-20 minutes.
Pull away gently then briskly and feel for shudder or slipping; watch the tacho for revs climbing without matching acceleration.
Ask for invoices proving the CVT fluid has been changed.
Any transmission warning light after the car warms up is a walk-away.

What it costs to put right

$4,000 to $8,000 at New Zealand independent workshop rates. That is for this job on its own, not for the car.

An estimate, in NZD, for the repair as normally carried out. What a specific car costs depends on which part has failed and what it damaged on the way — treat this as the floor for a negotiation, not a quote.

Ask the seller

“Has the CVT fluid ever been changed, and can I see the invoice?”
“Has the transmission ever been rebuilt or replaced?”
“Does it ever shudder or hesitate pulling away from lights?”

Now check the Mercedes-Benz B-Class you are actually looking at

Everything above is true of the model, and it is free. What it does not tell you is whether THIS car has been looked after: its odometer history and whether the reading has ever gone backwards, whether there is still money owing on it, whether it has been reported stolen, how many owners it has had and what it is really worth today. That comes from the official records for that plate. Enter the plate for the free details, or get the full history and a market valuation from $13.49.

Not sure what you would be paying for? See what a full KickTyres check includes.

Where this comes from

The failure described above is documented in the sources below. The inspection instructions and the cost estimate are KickTyres’ own interpretation of them.

MBClub UK 'B Class CVT Transmission Failure' thread
PistonHeads UK 'CVT in B200 Turbo - W245' thread
AUTODOC Mercedes B-Class common problems guide

Mercedes-Benz B-Class buyer questions

Is autotronic cvt (722.8) shudder, jerking and failure (w245) serious on a Mercedes-Benz B-Class?

We rate it critical and common on the Mercedes-Benz B-Class. The first-generation B-Class shares the A-Class's Autotronic continuously variable transmission, and it is the generation's most expensive weak point. The belt/pulley pack and its electrohydraulic control unit wear out, causing shudder pulling away, hesitation, flaring revs and eventually limp mode or no drive. Mercedes treated the fluid as 'sealed for life', which accelerated wear, so a car with no CVT fluid history is higher risk. A rebuild or replacement usually costs more than a tidy W245 is worth.

How much does it cost to fix on a Mercedes-Benz B-Class?

$4,000 to $8,000 at New Zealand independent workshop rates. That figure is for this job on its own. A car showing the symptoms on this page is usually worth either walking away from or negotiating down by at least the repair figure.

Which Mercedes-Benz B-Class years are affected?

Our research records this fault on the 2005–2011 Mercedes-Benz B-Class. Build dates move around, especially on imported cars, so treat the range as the years to look hardest at rather than a guarantee either way. The official records tell you the exact build and first registration date for the car in front of you.

How do I check for it before I buy?

Test drive from cold and again after 15-20 minutes. Pull away gently then briskly and feel for shudder or slipping; watch the tacho for revs climbing without matching acceleration. Ask for invoices proving the CVT fluid has been changed. Any transmission warning light after the car warms up is a walk-away. Look here: Transmission, mounted transversely behind the engine under the front floor