Spinning stud on rear engine carriage mount...

[RichPugh]

I had the car up on the lift and the engine supported with my motorcycle stand. I cranked off the drivers side 18mm nut without an issue... then the passenger side gave me a problem. It wouldn't budge so I sprayed it with PB and went back at it. I thought I broke my socket but it was fine. Put it back on and it seemed to be backing off... The nut has some resistance as if it was backing off reluctantly but I spun it for a while and noticed the nut not backing down the stud... SO... I assume the stud is broken, probably up in the rubber mount area and is just spinning.

I unbolted the top 13mm bolts in an effort to lift the top out but it wasn't coming up. I tried to lower the engine down a bit to simply try to pull the stud down out with the carriage and that didn't work either. I had planned to replace both rear mounts anyway (105k on the car and no clue as to when they were, if ever, replaced)... so... what are my options?

I think I have about 1/8" gap below the carriage and above the nut so it did move some... Am I sawzalling this thing off? I was gonna remove the bumper and exhaust anyway for what I'm doing.

[earossi]

I assume that you are talking about the nut on the motor mount bolt, right? I can't visualize the access to the that nut, but it might be easiest to use a Dremel tool to cut through the nut. There is not a lot of room on the bottom side of the mount.

[RichPugh]

I'm gonna try to hit it with an impact gun first and see if the resistance is enough to allow the impact gun to remove the nut slowly... kinda like the top nut on a strut when you don't have a tool to hold the shaft from spinning... thats what I'm dealing wih, LOL. PITA

[earossi]

Originally Posted by RichPugh

I'm gonna try to hit it with an impact gun first and see if the resistance is enough to allow the impact gun to remove the nut slowly... kinda like the top nut on a strut when you don't have a tool to hold the shaft from spinning... thats what I'm dealing wih, LOL. PITA

Worth a try. You're certainly not going to worsen things. Sounds like the stud head has spun in the interior of the motor mount.

[RichPugh]

Originally Posted by earossi

Worth a try. You're certainly not going to worsen things. Sounds like the stud head has spun in the interior of the motor mount.

Yep, that's what I assumed... Figured someone on these forums has had a similar issue and could suggest a smarter solution.

I've considered lowering the engine stand slightly to load the nut but I didnt want to relieve the carriage from the bottom of the mount stud square seat. I didnt think the stud was supposed to spin if the carriage was snug up against it and its square seat...

[RichPugh]

I got it. I let the engine down putting some downward pressure on the back of the nut and hit it with an impact driver for about 45 seconds. It sloooooooowly backed off but got the job done. Replacing soon with WEVO SS mounts prolly

Broken Porsche 993 motor mount spinning stud - YouTube

[Traveller]

From your video, it doesn't look like just the stud is spinning, but the whole interior of the mount with the rubber damper.

Those square ends on the stud should fit into the slots in the engine carrier...

[RichPugh]

Hey Alex,

Yeah, its the stud leading way into the interior of the guts of the mount... all spinning No biggie. I got it off and have ordered the WEVO black SS mounts. I am aware of how the top of the square stud base/seat sits into the top of the carrier slots. That's why I was worried about it spinning with the engine supported UP with a motorcycle lift! The carrier shouldnt have dropped while I was attempting to loosen the nut so I couldnt figure why/how it was spinning, assuming it was still seated in the carrier slots.