Tool for unbolting the ignition rotors on M119's

[Stevester 500E]

What is the correct hex size bit for the three bolts that hold the rotor?
Size 3 is what is stated as the correct size but it seems 3 is a slightly loose fit.

I have heard stories of people stripping the inside of the hex of the bolts.
I want to avoiding any pissing and moaning when I change out the ignition parts on my car.

Any tips, tricks or tool manufactures that sell a snug fitting hex?

 

[JC220]

3 is a loose fit but the correct size - don't use a ball end hex key just a regular 3mm one & go easy!

This has been discussed at length in this thread FYI-

http://www.500eboard.com/forums/showthread.php?t=1657

 

[Stevester 500E]

I plan on using some sort of anti seize and replace the bolts with other bolts.
I am just hope they come out ok with a size 3 hex.

 

[Raffaelli]

When I did mine a few stripped. Ending up having to hammer a torx on it to unscrew them.

 

[gsxr]

They are 3mm. Do not use ball-end hex drivers. With new rotors and a quality 3mm driver, there should be no problems. If a previous mechanic already buggered up the heads, there isn't much you can do besides replace the bolts.

DO NOT use anti-seize. If the bolts loosen, it will destroy the cap and rotor, pics below from one of my cars years ago. Now, I use a small amount of blue Loc-Tite.

 

[Stevester 500E]

I am calling this an incorrect tolerance, manufacturer error, period.
I took the approach of filing down a 1/8 bit down too a tight fitting 3.15.
"Party time, excellent!"

 

[Stevester 500E]

Holy cow, these look like 15 to 25 year old caps!

They are 3mm. Do not use ball-end hex drivers. With new rotors and a quality 3mm driver, there should be no problems. If a previous mechanic already buggered up the heads, there isn't much you can do besides replace the bolts.

DO NOT use anti-seize. If the bolts loosen, it will destroy the cap and rotor, pics below from one of my cars years ago. Now, I use a small amount of blue Loc-Tite.

 

[nocfn]

Anti seize made that mess? Did you use a quart of it?

 

[gsxr]

Anti seize made that mess? Did you use a quart of it?

No, that was when installed as per factory... dry! No anti-seize, no threadlock. I still don't know what caused the bolts to back out but 1 rotor bolt came totally out, 1 was very loose and almost out, and the third was still tight. Then, the single bolt for the rotor bracket also came loose and the locating pin sheared. Believe it or not, the car was driveable on 4 cylinders; happened while sitting at a stoplight (sudden rough running), made it ~30 miles back to my sister's house. Of course this was when traveling out of state and I had no spare parts, had to buy from a salvage yard at BOHICA prices. More photos here:
http://www.w124performance.com/images/M119/EZL/rotor_failure/

Ever since, I've been using blue Loctite! I would expect anti-seize could allow the bolts to be more prone to loosening, which is why I would never recommend it for this application.

 

[outrbnks]

3 is a loose fit but the correct size - don't use a ball end hex key just a regular 3mm one & go easy!

This has been discussed at length in this thread FYI-

http://www.500eboard.com/forums/showthread.php?t=1657

Read the thread, JC220 referenced, he came up with the solution, which I adapted

New size metric hex cap screws I had to special order from Fastenal M5 x .8 x 14 - they use a 4mm hex key unlike the MB screws.

https://www.fastenal.com/products/details/MS2540014A20000

I got the SS ones at .26 ea, had to wait about 7 days to get them, worth the wait, never strip screws again

Also picked up a nice quality Snap-on 4 mm Hex socket, Works perfect, fits these new cap screws perfectly..