Ok, I thought the motor mount R&R would be cake from all the postings on the board. Well, definitely the hardest part is removing the old motor mount.

While trying to undo the 18mm nut on the right mount, the bolt and nut got stripped within the mount. So both the nut and bolt are spinning within the mount.

How the heck do I remove the mount at this point? Any ideas would be appreciated. I was trying to figure out how this happened? I may have jacked the engine up a little too much??

The jelly sure does smell. A pic of what the mount looks like from Robin's site.


-nelson

 

Hi

Wow that is a good one.

Perhaps you can cut a slot in the nut to loosen it. You might have to remove some of the engine tin.

At least you can easily get to the top of the mount. Unless anyone has a better suggestion (and they will have) as a last resort cover the engine with an old towel or mask off with newspaper, and then grind the top of the mount off. Have a look inside and go from there. You might have to extract the innards, and I do not know what you will find, but I am sure you can get to the body of the bolt somehow and either grip or kill it.

I say to people when they are undoing these bolts to use plenty of penetrating fluid (and heat if you have access). Also be careful the nut does not bind to the carrier or else you can easily bend/crack the carrier.

If it goes well it is an easy job. I hope that someone has an easy fix for you.

All the best and good luck!

Berni

 

BTDT .... but the MM will come out

Check out this stripped MM R&R.

On installation, make sure that the square lugs are correctly lodged into the engine carrier before attacking top & bottom fastners: the floor jack on the case is the trick here .... not cranking on the 18mm nut to raise the engine.

 

A lot of times the impact gun at full torque setting will do the trick. If not, drill a hole into the top of the mount and yank a screwdriver or a center punch etc. in there.
Alternatively, you can undo the two bolts from the top and lift the motor as high as you can. This will allow access to the center rod. Maybe you can access it from there. I personally think the impact gun will take care of it.
Good luck and let us know how you did it.

 

Drill a large access hole through the top cover of the mount with an appropriate hole saw. That should give you plenty of room to grab the top of the bolt.





Andreas

 

Hi I had exactly the same problem. It's relatively easy to sort out. Jack up the engine so you have a bit of clearance between mount and carrier. The bolt has some flats on it just as it exits the mount. Have a look at a new one. You need a very thin open ended spanner (wrench?) push this in between the mount and carrier and this will hold the bolt while you unscrew the 18mm nut. The thin spanner should be 16mm. I had an old bicycle spanner in the garage. If you can't find one just make yourself one by cutting a 16mm slot in some strip steel. Difficult to explain but will be self explanatory if you are stood by the car.

If you were in the UK I would just post you my bicycle spanner.

Good luck.

pp

 

Ok guys thanks for all the suggestions. I swear, I don't know what I would do without Rennlist. I'll report back to let you all know how it went.

-nelson

 

An impact and a pry bar? Swing by Los Altos this weekend if you want me to help you with it...

Pete

 

lol..me needs one of those righ now..

 

Darn, looks like I may have to use the hole saw. The square lug is not moving as I turn on the nut. It also is partially out of the engine carrier.

-nels

 

Couldn't sneak in the 17mm wrench on the square lug? Did this last night and that trick saved me. Had to fit it in between the engine carrier and the car frame.

 

Allow me to add to my initial post .... firstly, the lug is 16mm ( as PP noted correctly), not 17mm: when I removed my 'spinning' mount, the lug was ( as we say in French ) buggered ... so a 17mm worked - as it will with a new mount if a 16 is not handy

Secondly, and of much greater utility ... that 16mm lug is a cast aluminium insert bonded to the rubber bottom cup of the mount .... the 'bolt' one sees in not a bolt, but a stud , threaded on both ends, one end for the lug and the other for the 18mm retaining nut.

Why go into that detail??? Well, if one captures the lug with a wrench as I first described in the link above , and then cranks on the 18mm nut - something must yield: either the nut spins off, or the stud spins out of the aluminium lug .... or the @#*&% stud snaps in two. Either of these three outcomes are equally satisfying .... for the mount then releases the carrier - job done.


So, lock onto that lug with a wrench & spin the 18mm nut!!!

 

Thanks Garth! I got it loosened. I just needed to jack the car up a little more and then I was able to get a skinny 16mm wrench in there. All is good now! The left side was much easier after I spent so much time with the right side.

So, just to be sure I installed them correctly, am I still supposed to see my exhaust tips move up slightly as I jack the engine up? Or does that mean I don't have the 18mm nut tight enough? I've cranked to 85 nm.

-nelson

 

Good job!

The 911 engines 'hang' on their mounts, so the MM is in extension vs. being in compression as for most other cars: when the 993 stock MM fails, it sags .... which is most easily evidenced by jacking the case ... and observing the exhaust tips move upwards.
Fresh stock mounts allow the car to be jacked by the case with no negligable ( if any) tip movement .... your RS mounts are a stiffness level above that, so I doubt that there would be even a fraction of a mm movement after torqued in place as you have done.