What is it?
The possibility that SLK R171 Owners can claim for a FOC replacement rear subframe because theirs has serious corrosion/cracking issues, making the rear subframe, unsafe due to issues with the manufacturing process? 

What are the Consequences of a Corroded rear subframe?
The corrosion and cracking can cause instability in; handling, cornering and fast driving, resultant MOT Failure, and, in extreme situations, the collapse of the rear subframe with its potential consequences. 

MOT Tests?
In most cases, the first thing the owner knows about the corrosion is when the car fails the MOT, or, in some cases, when the subframe collapses. Unfortunately, in less than 5% of cases of MOT failure or subframe collapse, there are no ‘Advisories’ on the subframes’ condition on the previous year’s MOT’s. 

Why doesn’t the corrosion get picked up on previous MOT’s?
The main issue is that the corrosion starts inside the subframe and corrodes its way out. So, by the time it is visible on the outside, it’s too late. The failures are usually under welded mountings so are difficult to identify on MOT’s. 

What is the process for claiming?
Contact the ‘Club Support Contact’ for a copy of the ‘Rear Subframe Replacement Information Sheet’ and follow the instructions; General Methodology: Email - Mercedes Benz Customer Service UK (MBCS UK) and ask about getting the subframe inspected and possibly replaced? They will inform owners that they will need to get the subframe inspected by a Mercedes Benz Dealership in their area (NOTE - MB will not accept a 3rd Party Garage report).

Contact the local Dealership and Book the vehicle in for a Safety Check and Rear Subframe Inspection. (NOTE - there are some Good Dealerships and some Dealerships that should be Avoided). 

What does this entail and, what does it Cost?
The Dealership will offer you a time to bring the vehicle in for the inspection. The Inspection is generally carried out FOC (Free of Charge) the Dealership produces a video of the safety check and email it to the Owner.

The subframe should be inspected, using an Endoscope to look inside the subframe and check for corrosion and cracking. 

What happens if the Dealership wants to Charge for the inspection?
Generally, if the Dealership wants to charge for the inspection, the owner mentions that they are a member of: SLKOwnersClub.Co.UK and, that Club members Nationwide, have had theirs inspected FOC. If the Dealership still wish to charge, it is suggested that the owner take it to another Dealership. 

What happens next?
This depends on the Dealership – Good Dealerships; If the subframe requires replacement, they pass on the results of the inspection on to MBCS UK, requesting authority to change the subframe due to the corrosion.

In most cases, if the subframe is seriously corroded and requires changing, the Dealership will retain the vehicle until the subframe has been replaced – this is for Safety Reasons as some Club members have had their subframes collapse whilst they have been driving the vehicle. So, this is a positive action on the part of the Dealership. It is worth noting, that the owner may need have to arrange transport to return home without their vehicle. 

What happens when the vehicle is repaired?
There may be delays, as the quantity of subframes available in the country at any one time, can be limited and sometimes owners must wait for subframes, and/or components, to be delivered from the manufacturer.

The subframe and its component parts ‘should’ be replaced FOC under the Mercedes Benz Goodwill Warranty, Some Dealerships may try to charge for replacement of components that are attached to the subframe.

When the owner collects the vehicle, they may be given a Receipt/Invoice, stating that the subframe has been changed (It is worth noting that Dealerships only give detailed invoices, in about 1/3 of cases). 

What do owners do next?
It is suggested that owners should invest in an endoscope to check on the new subframe and, apply protection to the new subframe inside and out once it has been fitted, to ensure that the subframe does not corrode again.

 Possible Issues and Actions 

The Dealership may want to charge for the inspectionThis should be challenged as Club members, Nationwide, have had theirs inspected FOC. If the Dealership still want to charge, try another Dealership.
Dealership may want the owner to sign a pre-agreement, agreeing to pay up to £1800 in advance, for components that may have to be replaced as part of the subframe changeOn no account should the owner sign such an agreement, * Contact Club Support for information and support in this matter!
The Dealership may try to charge for the replacement of component parts (sometimes Dealerships say that they can’t get components off the old subframe) despite them being serviceable.This should be challenged by the owner, contact the Club Support Contact as, according to the emailed letter from a Dealership Group, replacement of the subframe and its components should be covered by the MB Goodwill Warranty
The Dealerships say that the subframe is Safe and Serviceable after inspection.Request a receipt to that effect, and always get a second opinion with an Independent Garage. One club member had theirs collapse 2 months after they were told that the subframe was safe and serviceable.
Are there any components not covered by the MB Goodwill Warranty?Yes, Rear shock absorbers and road springs also hubs & bearings, callipers (inc. Pads & discs), brake pipes.
Despite the Dealership saying that the subframe should be replaced due to corrosion, MBCS UK refuse to replace it*Contact Club Support and request further information and support to the Stage 2 part of the claim process.
Dealership refuse to inspect the subframeTry another Dealership
Dealership don’t undertake Tracking or 4 wheel alignment after subframe replacementThe Dealership should undertake tracking and/or 4-wheel alignment as a part of the subframe change.
Dealership may want to charge for and replace the brake-pipes under the subframe as part of the change.This is down to the owner, the cost of this work should be ascertained prior to work starting – it will almost certainly be more expensive than having it done by an Independent Garage, so beware!
Some Dealerships may try and charge for Bolts and Nuts to fit the subframe to the chassis/bodyThese should be covered by the MB Goodwill Warranty these charges should be argued *Contact Club Support
Some Dealerships or MBCS UK refuse to replace subframe if it has been welded.Owners should point out that the subframe wouldn’t have needed welding if they hadn’t been rotten in the first place! 15 of the subframes that have been changed FOC had been welded.
Some Dealerships request that the vehicle has a Full Mercedes Benz Service History. (FMBSH)Out of 48 subframes that have been changed FOC only ONE has had anything like a FMBSH
What if there is a Subframe Failure/collapse?There would be a loss of control of the vehicle, rear wheel collapse/loss, carefully drive the car to safety or, have the vehicle recovered safely.
Subframe identified as being severely/dangerously corroded either, by a service garage or an MOT Testing CentreHave the subframe inspected as soon as possible for safety reasons and drive the vehicle carefully to the nearest Dealership.
How to go about finding a Good Dealership in the owners’ areaThe Club Support Contact had compiled a list of ‘Good Dealerships’ and ‘Dealerships to be Avoided’, in most areas of the UK and Northern Ireland, information is only compiled from Owners/Members Feedback.

What help is available on the Club site for this Corrosion Issue?

We have a Club member who has accumulated a substantial amount of information and data regarding this issue and they have produced a number of ‘Rear Subframe Replacement Information Sheets’ for various Stages of the Claims Process, for SLK R171’s, R172’s and other Mercedes Models that suffer from similar corrosion issues.

The Information Sheets and other support information is available to all SLK Owners from the Club Support Contact - Dave Evans on the SLKOWNERSCLUB.CO.UK - Facebook Page or, by Email to:  dave@castellni.co.uk