S63 AMG Coupe wheel centre cap

[chic0821]

I have an S63 AMG Coupe with the dummy centre lock wheel centres, What a job removing them with the plastic removal tool which kept slipping off. Wheels off for Gtechniq wheel armour & calliper bells repaint. All good until replacing the centre cap which has a plastic thread. Was a bit tight then it broke. It is a three part design, back plate, plastic threaded part & dummy nut, all clipped together. Can I just buy the threaded part, no. Full assembly only £150 . Had a good look to see what happened. Their are five bosses on the back plate which should be located in the wheel nut counterbores before screwing it on otherwise they sit against the wheel & when tightening it goes tight so you tend to think its a high spot so tighten it a bit farther & it breaks.
I decided rather than pay £150+ for a new cap, I would modify the old one, so after throwing away the broken plastic threaded part, I was left with the back plate & nut. Original plan was to tap 3 equi-spaced holes in the wheel, but as there are 5 wheel nuts & an additional 5 holes equi-spaced on the wheel this would not work. 5 equi-spaced holes would work, but that's a bit overkill considering what is to be held on. I decided to go for 2 screws, but they cannot be exactly opposed , so decided to make them opposed as near as possible .
Placed back plate in position & drilled 2 pilot holes through it & into the wheel. Decided to go for M4 x 8mm stainless button head screws. 3,3mm drill into the wheel about 12mm deep, then tapped M4 by around 10mm deep. Opened up the holes in back plate to 4.5mm clearance. Good to go after checking the screws fitted perfectly.
Used JB weld 2 part epoxy glue to hold the nut to the back plate. Let it fully cure over night. Touch of copaslip on screws, then screwed it in position. Using M4 button heads, would not be noticed unless actually looking for them. Comments ??

 

[AMGeed]

Good job!
Got to be better than spending £150 on a replacement. Crazy money

 

[Atavus]

This thread was useful for me. The tyre guy got one of these stuck the other day when fitting my rear PS4S.

The plastic tool for fitting the centre caps was starting to round off where the 17mm socket attaches. I suggested he stop there and I’ve ordered a new tool.

Today I attached the old tool to my Dewalt impact (DCF887 little one). On setting 2 it was able to back out the wheel centre. Gave the wheel threads a clean with a brass wire brush then correctly fitted the wheel centre. The impact driver can turn the rounded off hex when it just yields when you try a normal wrench.

 

[23 Romeo Tango]

I only ever put these on hand tight, no tools ever used. In the dozen times I installed/removed the centre caps I didn't have any issues other than getting the thread started could be a little awkward at times.
I found a small application of copper grease (or similar) to the wheel threads often helped stop any grit getting on the threads.

The times I've heard of or seen issues with these centre caps, torque tools, sockets or spanners have been used and probably over tightened them.

Great result for the OP, they look like they could be the original design.

 

[C240Sport97]

doesn't look right to my eyes .. the 2 screws spoil the look

 

[bmb1959]

Not as bad as looking at a hole in your wallet where £150 used to be lol