Help with M104 cylinder head bolt. - PeachParts Mercedes-Benz Forum

jmerc6 · #1 12-06-2008, 03:05 PM

Today I was in the middle of removing the cylinder head bolts. I was able to loosen all but one. The head is stripped so that my socket won't grip. Anybody else have that happen? How can I remove this last bolt?

Another question I've got is the "pin" that holds the timing chain guide. I screwed a 6mm bolt into it with a socket, washer, and nut, but I can't get it to budge. What I'm doing wrong? I'm afraid that I'll break the plastic chain guide.

babymog · #2 12-06-2008, 04:19 PM

A slide-hammer will remove the pin, some have been successful with washers and spacers to drive it out.

The stripped bolt head can be overcome with bolt removers. There is a set that works well for me, made by IRWIN, Autozone, Advance Auto, NAPA, and others stock it. It comes in a blue plastic case (or without), the sockets look like black 3/8 drive sockets with an external hex for turning it with a wrench (as an alternate to turning it with a ratchet). Has an internal reverse-helix that drives down onto a bolt head and turns it out.

jmerc6 · #3 12-08-2008, 09:25 AM

The bolt heads on the M104 are not hex head but torx. Will those easy outs still work?

Turbo E320 · #4 12-08-2008, 09:30 AM

A torx bolt is just like any other when it comes to bolt removers. Get a non-drill type properly sized for the bolt and if that doesnt work get a properly sized drill type easy out.

By non-drill type I mean you dont have to drill into the head bolt to insert the bolt extractor. Obviously drill type means you have to drill into the bolt.

whipplem104 · #5 12-08-2008, 11:40 AM

An easy out is going to be your only chance before drilling the head off.
The bolt is not a torx though. It is a 12point. Also as far as the guide rail pin. You should use a slide hammer tool if you do not have the proper pin puller.

babymog · #6 12-08-2008, 12:39 PM

Yes.

I bought mine on a recommendation on the Diesel forum when I had a bit broken in the head bolt, no easy way to drill it out. Worked great, the IRWIN socket grips around the outside of the bolt head instead of the inside. In the case of one bolt, I had to grind the external hex off of the socket/easy-out to be able to fit it in the hole, but on other head bolts no problems at all.

Inexpensive, I believe the set cost around $20 at autozoo.

Quote:

Originally Posted by jmerc6

The bolt heads on the M104 are not hex head but torx. Will those easy outs still work?

jmerc6 · #7 12-08-2008, 03:17 PM

Went by NAPA today and showed them one of the bolts that I am trying to remove. Told me all they had was a drill-out. Also told me that it wasn't a torx but a 12 point. Bought the 12 point bit but not the easy-out. Going to try somewhere else. I live in a small town in TN and somethings are not easy to find.

babymog · #8 12-08-2008, 03:43 PM

Ouch. The NAPA here stocks them, so do the Autozone and Advance Auto, hopefully you'll find them in stock.

jmerc6 · #9 12-09-2008, 11:06 AM

It's amazing how well things work when you've got the right tools! Thanks to the NAPA guy I got the 12 pt. instead of the torx. I gently tap it into the socket and with a 24" breaker bar got it loose.
Now to the other problem. Any suggestions about a slide hammer to remove that stubborn timing chain guide pin? I've got a 6 mm by 50mm bolt but I think I may need a much longer bolt.

Hirnbeiss · #10 12-09-2008, 11:48 AM

Quote:

Originally Posted by jmerc6

It's amazing how well things work when you've got the right tools! Thanks to the NAPA guy I got the 12 pt. instead of the torx. I gently tap it into the socket and with a 24" breaker bar got it loose.
Now to the other problem. Any suggestions about a slide hammer to remove that stubborn timing chain guide pin? I've got a 6 mm by 50mm bolt but I think I may need a much longer bolt.

Don't forget the right emoticon. You need a

or similar for that one.

I have always had success easing the pin out with a stack of washers to provide leverage for the bolt to pull against. It sounds like you already removed the timing cover - maybe you can temporarily reinstall so the washer can push against that instead of the chain guide.

jmerc6 · #11 12-09-2008, 02:12 PM

You're exactly right. I did remove the cover first. I'll reinstall and try again. Thanks

jmerc6 · #12 12-10-2008, 10:26 AM

When I went to reinstall the top cover to remove the pin, I saw no access hole to get to the pin. If I put the cover on, how will I get to it?

whipplem104 · #13 12-10-2008, 11:16 AM

What you want to do is put a nut on the bolt and then a spacer. Anything will work, a socket or a piece of tube steel. On the m104 you can push against the rail since it is aluminum. thread in you bolt and then use the nut to pull out the pin.

jmerc6 · #14 12-10-2008, 12:35 PM

I'm a little confused (obviously). The rail I'm looking at is plastic. I fear it can't take the pressure. My car is '91 300CE.

jmerc6 · #15 12-10-2008, 01:42 PM

Well I check the rail again. This time I put on my glasses, turned on the lights, and wiped the black oil. Guess what?! It isn't plastic! It is aluminum. I trusted my guides and did use a spacer and put a little more pressure and presto. It can right out. Thanks again!!