Broken motor mount, can it be welded?

KCinBR · KCinBR's Garage

In the process of dropping the motor today we found the motor mount broken, like the mount twisted when we were trying to get the bolts out. Here is a pic let me know what you think. I can get it welded at work and reinforced a little also or should it be replaced?

KTL · 11-19-2007, 03:37 PM

Happens quite often. You can have that welded. Just clean it up good and make sure it's bent back into place square. The original part was welded to create the mount bar, so no big deal welding it back together. Just be sure there's good meat to weld on, and reinforce with additional plates if need be.

A good weld is obviously important!

911 in SC · 11-19-2007, 03:39 PM

You know, I was thinking about it - do you think I broke it when I was trying to break the bolt loose?

Just kidding. I certainly hope I didn't break it!

burgermeister · burgermeister's Garage

Agree with KTL. That area sees mostly shear loads (except when breaking motor mount bolts loose of course), so a good weld should make it good as new.

Joe Bob · Joe Bob's Garage

I have one sitting here on the shelf....make me an offer.

klaucke · 11-19-2007, 04:06 PM

It's a very common break when removing the old bolts, I once had one do the same thing. Welded it up and never looked back.

KTL · 11-19-2007, 04:09 PM

Quote:

Originally Posted by 911 in SC

- ...........do you think I broke it when I was trying to break the bolt loose?

Just kidding. I certainly hope I didn't break it!

Actually, I bet that's how the majority of them actually do break!!!!

That's how I broke mine. A local friend had the same problem. Darn bolt wouldn't let go and tore the bar. Next time I do an engine drop on an engine that's been undropped for a long time, i'll be heating the bolts up a bit to break them loose. Or just fire up on the impact wrench........

911 in SC · 11-19-2007, 04:17 PM

Hmmm, interesting. Sorry about that KC!

So do you recommend reinforcing it too? It certainly wouldn't hurt, would it?

Where are the pics of the clean engine bay and tranny? I can't wait to see them!

KCinBR · KCinBR's Garage

Quote:

Originally Posted by 911 in SC

Hmmm, interesting. Sorry about that KC!

So do you recommend reinforcing it too? It certainly wouldn't hurt, would it?

Where are the pics of the clean engine bay and tranny? I can't wait to see them!

Yes I'll be renforcing them also, maybe both sides.

I sent the pics to you about hour and a half ago, must got stuck in the line.....hre's one

DUK · 11-19-2007, 04:24 PM

I did the same exact thing. Here's what I did to fix and reinforce it. (plus I added some holes, there's nothing lighter than a hole, right?)

KCinBR · KCinBR's Garage

Nice Duke, but I probably wont do the holes, I mean I have a Carerra with power seats and windows and AC and lots of other stuff that adds much weight. So I'll weight

on doing the holes untill I loose all the other stuff.
Thanks for posting the pic, now I know exactly how to do the repair.

911 in SC · 11-19-2007, 04:32 PM

Great pics. Yeah, I just got them. Man, it cleaned up quite nicely! I'm impressed. Hopefully you'll be able to keep it that clean.

I can't wait to do mine next! Then again, that means I won't get to drive it. Not sure if I want to do that...

911pcars · 11-19-2007, 05:51 PM

My suggestions. Reinforce the mount with additional material, top and bottom. Duke's version looks fairly rigid.

In addition, convert over to the early style, nut and bolt arrangement instead of the thread-on bolt. That way, With a nut to counter-hold, there's less twisting force on the ends when loosening and/or tightening the bolt.

Adding lightening holes helps offset the increased material weight needed to reinforce the ends. Every little bit helps.

Sherwood

Mitch Leland · Mitch Leland's Garage

Sherwood, are you saying you could drill out the threads of the captive nut on the engine support and use a nut with a longer bolt?

911pcars · 11-20-2007, 11:15 AM

Quote:

Originally Posted by Mitch Leland

Sherwood, are you saying you could drill out the threads of the captive nut on the engine support and use a nut with a longer bolt?

Yes sir. As a result, you will have a retro engine mount bar (same as early 911). No where else on the entire car is there such an arrangement; 60 ft.lb (or so) torque applied to a fastener at the end of a longish lever. The applied loosening and tightening force is concentrated on the weakest section of that lever - NG.

Sherwood