- Joined
- Jan 31, 2016
- Messages
- 979
- Location
- Fleet, Hampshire
- Car
- 2008 CLK 350 Sport Cab and 2021 BMW 520i M Sport Saloon
Symptom:
The number plate screws for your rear plate spin and spin. You can’t undo them because the thread into which they screw is spinning behind the boot panel.
Reason for Problem:
MB, in their infinite wisdom, use steel screws to secure the plates. But the threads into which the screws are fixed are made from aluminium. Over time the steel screw and the aluminium thread weld together and then when you try and undo the screw, the thread becomes detached behind the boot panel and spins with the screw. Rather like having a bolt on the rear of the boot panel and it spinning freely when you turn the screw from the front.
How to Fix It:
This happened to me on my 209 CLK cabrio. But it is a common fault on many MBs. Firstly, there is no point hoping that by pulling, spinning or applying any kind of force from the outside that they will shift. All you risk doing is slipping with your screwdriver and gouging the paintwork. So stop right now!!!
You need to remove the interior boot panel. On my W209 2008 CLK, this was quite simple. The inside of the boot lid is lined with carpet panelling held in place by those commonly used black plastic round press through clips. Get the claw from a small claw hammer under each clip and gently lever each one away. I managed to remove all of mine without damaging the clips and they could all be refitted. If you do damage a clip, Merc can supply them I’m sure.
On the CLK you need to also remove the warning triangle and the plastic holder for it. The warning triangle holder clips in. You kind of jimmy it out and slide it to one side at the same time. Hard to explain but a bit of careful levering and sliding and you’ll find it pops out. It is not held in by screws – just clips and slides into position.
Finally on the CLK loosen off the hex bolts around the boot handle and boot catch. You don’t need to remove the whole handle – just loosen enough to free the carpet panel from under it.
Remove the carpet panel carefully. Watch out for wires – your GPS antenna and other gubbins is all in close proximity so careful not to dislodge anything.
Once removed you should be able to see the threads into which the number plate screws locate. They look like aluminium “rawplugs” and there are four of them. Get a sturdy pair of pliers and grip the thread “plugs” which are giving the issue. Access is a bit tight so watch your knuckles!
From the other side unscrew the steel screw. This is a two person job. Get someone to grip the plug thread on the inside tightly whilst you turn the screw from the outside. It will be VERY tough to break the corrosion seal so a steady hand and a good screwdriver is required.
I packed an old towel around the number plate to protect my paintwork should I slip with the driver whilst trying to undo the screw. I did slip a couple of times and am glad I had a towel there to protect the paint.
Eventually you should be able to get the screws out.
If the threads really are welded to the screw and won’t unscrew as suggested above you have two options.
Either snap away the number plate from the outside so that you can see some screw thread from the outside. Then carefully use a junior hacksaw to cut the screw just below the head and remove the whole screw and thread from inside. Or, if you can get access, cut them off from the inside with an angle grinder or cutting tool.
If that seems too horrific, snap the old number plate off, leave the old screws in situ and fit a new number plate holder over the old screws using self adhesive pads. A bit of a bodge, but I think this would work OK if you needed to.
Once done, reassemble, sit back and marvel how a job which you expected to take 10 minutes ended up taking two hours!
This guide is specific to the CLK, but I strongly suspect all MB’s are assembled in a similar way and the same principles apply to all models.
The number plate screws for your rear plate spin and spin. You can’t undo them because the thread into which they screw is spinning behind the boot panel.
Reason for Problem:
MB, in their infinite wisdom, use steel screws to secure the plates. But the threads into which the screws are fixed are made from aluminium. Over time the steel screw and the aluminium thread weld together and then when you try and undo the screw, the thread becomes detached behind the boot panel and spins with the screw. Rather like having a bolt on the rear of the boot panel and it spinning freely when you turn the screw from the front.
How to Fix It:
This happened to me on my 209 CLK cabrio. But it is a common fault on many MBs. Firstly, there is no point hoping that by pulling, spinning or applying any kind of force from the outside that they will shift. All you risk doing is slipping with your screwdriver and gouging the paintwork. So stop right now!!!
You need to remove the interior boot panel. On my W209 2008 CLK, this was quite simple. The inside of the boot lid is lined with carpet panelling held in place by those commonly used black plastic round press through clips. Get the claw from a small claw hammer under each clip and gently lever each one away. I managed to remove all of mine without damaging the clips and they could all be refitted. If you do damage a clip, Merc can supply them I’m sure.
On the CLK you need to also remove the warning triangle and the plastic holder for it. The warning triangle holder clips in. You kind of jimmy it out and slide it to one side at the same time. Hard to explain but a bit of careful levering and sliding and you’ll find it pops out. It is not held in by screws – just clips and slides into position.
Finally on the CLK loosen off the hex bolts around the boot handle and boot catch. You don’t need to remove the whole handle – just loosen enough to free the carpet panel from under it.
Remove the carpet panel carefully. Watch out for wires – your GPS antenna and other gubbins is all in close proximity so careful not to dislodge anything.
Once removed you should be able to see the threads into which the number plate screws locate. They look like aluminium “rawplugs” and there are four of them. Get a sturdy pair of pliers and grip the thread “plugs” which are giving the issue. Access is a bit tight so watch your knuckles!
From the other side unscrew the steel screw. This is a two person job. Get someone to grip the plug thread on the inside tightly whilst you turn the screw from the outside. It will be VERY tough to break the corrosion seal so a steady hand and a good screwdriver is required.
I packed an old towel around the number plate to protect my paintwork should I slip with the driver whilst trying to undo the screw. I did slip a couple of times and am glad I had a towel there to protect the paint.
Eventually you should be able to get the screws out.
If the threads really are welded to the screw and won’t unscrew as suggested above you have two options.
Either snap away the number plate from the outside so that you can see some screw thread from the outside. Then carefully use a junior hacksaw to cut the screw just below the head and remove the whole screw and thread from inside. Or, if you can get access, cut them off from the inside with an angle grinder or cutting tool.
If that seems too horrific, snap the old number plate off, leave the old screws in situ and fit a new number plate holder over the old screws using self adhesive pads. A bit of a bodge, but I think this would work OK if you needed to.
Once done, reassemble, sit back and marvel how a job which you expected to take 10 minutes ended up taking two hours!
This guide is specific to the CLK, but I strongly suspect all MB’s are assembled in a similar way and the same principles apply to all models.
