85 300D engine mount changeout.%#@! I stripped a hex bolt... - PeachParts Mercedes-Benz Forum

Carrameow · #1 05-20-2002, 08:24 AM

I 'm trying to change out my engine mounts on my 300D. There are those hex bolts that you have to undo from the bottom of the car holding the engine to the mounts. I stripped one. Does anyone got amy ideas?

haasman · #2 05-20-2002, 11:54 AM

You stripped the head of the hex bolt?

If there is room I would try an EZ Out. Take another like bolt to a tool store. Have them match the EZ Out to it. The $64,000 question is to check and see if the EZout will have enough room.

I have been there ... I now use some sort of a flush to clean out debris out of the head. I also whack the allen socket securely making sure it is seated before starting to back 'em out. I just showed this to my son and daughter the other day while working on the car with them.

savagetom · #3 05-20-2002, 04:59 PM

Bummer! The socket head on these bolts is pretty deep. If you are really, really lucky you will be able to clean out the socket well in the head of the bolt to get the hex driver in deeper. Also, buy some valve lapping compound and dip the hex driver in it before inserting into the bolt. The abrasive will help get a better bite. Many people suggest loosining the bolt with a surge instead of steadily increasing pressure on the wrench.

haasman · #4 05-20-2002, 05:27 PM

savagetom

valve lapping compound. What a great idea! Tighten it up a bit.

Carrameow · #5 05-21-2002, 12:20 AM

1. If I drill the head off (its too thin for an EZ-out) and then Raise the engine with a Hoist and remove the mount, will enough of the shank be left to get a grip on with vise grips? Please don't laugh.

2.Fill the allen hole with heavy duty Epoxy Putty and then hammer a 10mm Metric socket in place and let the thing harden overnight? Please dont laugh

mikemover · #6 05-21-2002, 03:14 AM

Is there room to get a VERY large pair of vise-grips on it?

Mike

Ashman · #7 05-21-2002, 03:29 AM

is there room in the head to grind a slot in it for a flat head screwdriver?

Or can you JB weld a piece in there so you can then remove it?

Or maybe you can have something welded on it to be able to remove the bolt.

Alon

fasthair · #8 05-21-2002, 01:23 PM

One of the best tools in my box for just this thing is a set of screw extractors. Snap On sells them as does Matco tools and I would guess Mac does too. This tool works real well for removing rounded out alllen head bolts that are deep inside a hole or otherwise hard to get to fastners. Look at the photos I have posted and I think you will see just how well they will work for you. FYI I had this very same problem last week on a 450SL and used these to get the bolt out. Good luck.

fasthair

savagetom · #9 05-21-2002, 08:18 PM

My son snapped one of these bolts when reinstalling the mount on his 300D. Still not sure why unless the bolt was in a terrible bind against the side of the mount. He ended up having to remove the arm from the side of the engine. There was just enough sticking out to back it out with a screwdriver. The passenger side mount is difficult to remove because it is under the turbo and a bracket that holds the air filter drain line. Good luck! I'm sure you'll get it.

sainttammany · #10 05-30-2002, 12:00 PM

I had this happen on my 82 300d. The bolt holding the mount was I think a 7mm allen hex. I think I turned it the wrong way first, rounding the hole. The fix was easy. I used a the largest titainium drill bit that would fit in the allen hole and turn without binding. It went through that hardened bolt like butter, realeased the pressure on the threads and came out by hand. I took the motor mount off and put a thread insert in it.