Stripped motor mount bolt - HELP needed ASAP - Page 2 - PeachParts Mercedes-Benz Forum

PatricdeBoer · #16 01-31-2008, 01:10 AM

I had a similar thing happen to me on my 300sd. I just jacked up the engine and unbolted the whole arm. It is held on by 4 bolts and they are all pretty easy to get at.

JimmyL · #17 01-31-2008, 01:26 AM

Well, when I had some frontend work done on my wagon in my early MB days, the guy called and said I needed engine mounts and that he wouldn't charge much to put them on. Sounded fine to me.
I picked up the car and he said one of the mount bolts was stripped so he pounded a torx head or similar socket into the allen bolt and removed it that way. Cool.
Then I was horrified to find out that he put that same bolt back in.....

I will have to deal with this some day......

ImBroke · #18 01-31-2008, 09:13 AM

Quote:

Originally Posted by JimmyL

Then I was horrified to find out that he put that same bolt back in....

I couldn't in my right mind do that, unless you absolutely needed the car back.

Chad300tdt · #19 02-02-2008, 05:09 PM

So I thought I'd give an update on the stripped bolt.

I went to SEARS and purchased the Bolt Out set.
They don't fit though the hole in the cross-member to reach the bolt head.
Went back to SEARS and got a set of Craftsman torx sockets.
Since this will probably ruin the socket, the lifetime free exchange warranty will come in handy.
I had everything in position with the motor jacked slightly to lift it to the proper position since the right mount is torn in two.
Then my floor jack ruptured.

It was a cheap POS from Pepboys (2-1/4 ton).
I went back to SEARS and got a new 4 ton floor jack which was on sale for $100 and upgraded to 4 ton jack stands.
I never should have been using the other set.
The new jack lifts to full extension in two pumps.

I'll have to try heating the bolt and seating the torx socket with a 3 lb hammer tomorrow.
The torx socket will definitely fit.
I just hope it saves me from having to drill the bolt out.

BTW, new 8mm bolts for the motor mounts are $8 a piece from the dealer.
I have two on order right now along with the 4 lower shock bushings.

More good news: The torn mount allowed the belts to rub the lower radiator hose and it has a weeping pin hole now. (I already have the new one)
I also noticed the front left caliper is leaking.

Looks like I'll be doing those before the wagon goes back on the road.

Here's a pic of the new jack and stands. This was the highlight of my day.

Chad300tdt · #20 02-06-2008, 01:34 PM

OK. The torx bit didn't do the trick.

I heated the bolt until the mount was good and smokey (about 90 seconds). Then I seated the bit with a 3lb hammer. The bit spun easier than the hex bit did. The next size torx bit is too big to bash in there.

I just sprayed the mount arm nuts with PB Blast and I'm giving it some time to work. Then I'll try loosening the arms. If I can loosen all 4 nuts on each arm, I'll retighten them and jack the motor to rip the mounts and then take the arms off.

If I can't loosen all the nuts on the mount arms, I'll drill the mount bolts out.

chuni959 · #21 02-06-2008, 04:17 PM

can you get a sawzall in there? hahah sounds funny, i know but the same thing happened on my friends 201 and we sawzalled through the entire metal arm to get it off

Chad300tdt · #22 04-05-2008, 10:44 PM

I finally got those motor mounts off today. I ended up drilling the head off of the stripped bolt and taking out the mount arm to remove the shaft of the bolt. Both mounts were shot, but the passenger side was torn in two and felt gummy from the oil that leaked all over it from the old rotted wastegate hose.

The bolt head drilled off very easily. I used Aerokroil to lube the drill bit and I cut through it in about 5 minutes. Looks like these bolts were designed to be drilled off if necessary.

Here are the old mounts and driver side mount arm.

Check out the mess I still need to clean up from that wastegate hose.

This stuff is awesome. I used it to lube the drill bit, loosen the frozen nuts, and it’s a great air tool lube.

A) Stud for motor mount arm, B) Hole for motor mount, C) Bracket for oil cooler lines. As you can see, the oil cooler lines are pretty easy to get at without the mount arm in the way. I think it will make replacing them much easier.

chuni959 · #23 04-05-2008, 10:48 PM

Chad300tdt · #24 04-05-2008, 11:02 PM

Ha! Nice pic.

Chad300tdt · #25 07-30-2008, 09:53 AM

I just wanted to give credit to DAR2KMR2 in post #15 for offering the suggestion that finally worked. I couldn't imagine the shaft of the bolt unscrewing with my fingers, but it was absolutely true.

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