Engine: Separated Motor Mount

[JoeHall]

Yesterday in the 63GT, I turned at light and goosed it a bit due to oncoming traffic. Heard the fan blade kissing the shroud, and simultaneously felt a shift in the gas pedal pressure. Don't even need to look at it, been down this road many times. Due to torque under acceleration, the motor tries to lift on the left side, eventually the vulcanized rubber in the left motor mount lets go, and the motor lifts. The right side mount is never a problem, since the motor pushes down on that side, while lifting on the left side.

The fix is easy, a small linked chain bolted to the top mount stud, and ran to a frame mound bolt just below. I leave a bit of slack so the motor will not vibrate as if in a solid mount. But when the motor begins to lift, the chain tightens and holds it in place. I have left the chain in place on the 62GT for decades, and cannot believe I did not install a chain in this car when I first got it, about 30,000 miles ago.

[Mike Van Veghten]

Another simple fix is to either buy a similar sized doughnut with a thru hole, or just modify the stock mount by removing the studs and drilling a thru hole.
Put it back in place with a longer bolt, washers and lock nut.
Or you can add another measure of safety and comfort by placing a thinner piece of rubber "under" the mount with a properly sized bolt.

I've done it with and without the second piece of rubber, with no obvious felt difference (currently this way on my daily driver Lark wagon) without the under piece of rubber.

AND...there's no nasty hunk of chain anywhere in the engine compartment.

Though...MANY years back, I did use a chain to hold the hot rod engine down in my 56 Chevy. No broken mounts...just front mounts stretched to the limits with more torque than the mount system was designed to take.

Mike

[DEEPNHOCK]

Chevy got sued back in the late 60's/early 70's when their motor mounts would separate, the engine would rock over and jam the throttle open.
Several accidents and deaths were reported.
This caused the entire GM line to go to 'interlocked' motor mounts.
Nothing new...
And the solutions offered up here are all good.
Use the KISS system and make your engine stay put.
New mounts....and a positive retention method....

[Flashback]

Used 32 Ford mounts on my 53. Won't have to revisit. Course, at my age, I probably would never had to replace them anyway. LOL

[bensherb]

Chevy got sued back in the late 60's/early 70's when their motor mounts would separate, the engine would rock over and jam the throttle open.
Several accidents and deaths were reported.
This caused the entire GM line to go to 'interlocked' motor mounts.
Nothing new...
And the solutions offered up here are all good.
Use the KISS system and make your engine stay put.
New mounts....and a positive retention method....

Chevy's imediate fix was to run a short cable around the upper control arm shaft and bolt it to the block. Same idea as your chain but quieter.

You can also replace the Stude mount with the bisquits from the early Chevy V8 mounts and an appropriate length bolt. These are urethane, the stock ones are rubber. https://www.ebay.com/itm/Engine-Moun...5ZSk1M&vxp=mtr

[tsenecal]

I remember seeing that short safety cable on some older Chevys. Never knew it was the result of a law suit.

[bensherb]

I remember seeing that short safety cable on some older Chevys. Never knew it was the result of a law suit.

Yea, it was actually installed as a recall. GM recalled almost 7 million 1965-70 Chevy's in '71 or '72 (don't remember?) and installed that cable. I had a '66 Caprice at the time and had to take it in.

[sals54]

Another simple fix is to either buy a similar sized doughnut with a thru hole, or just modify the stock mount by removing the studs and drilling a thru hole.
Put it back in place with a longer bolt, washers and lock nut.
Or you can add another measure of safety and comfort by placing a thinner piece of rubber "under" the mount with a properly sized bolt.

I've done it with and without the second piece of rubber, with no obvious felt difference (currently this way on my daily driver Lark wagon) without the under piece of rubber.

AND...there's no nasty hunk of chain anywhere in the engine compartment.

Though...MANY years back, I did use a chain to hold the hot rod engine down in my 56 Chevy. No broken mounts...just front mounts stretched to the limits with more torque than the mount system was designed to take.

Mike

Ditto, Mike. That's exactly how I do them.

[Bordeaux Daytona]

Chevy got sued back in the late 60's/early 70's when their motor mounts would separate, the engine would rock over and jam the throttle open.
Several accidents and deaths were reported.
This caused the entire GM line to go to 'interlocked' motor mounts.
Nothing new...
And the solutions offered up here are all good.
Use the KISS system and make your engine stay put.
New mounts....and a positive retention method....

I had this happen when I tried flooring it or was brake torquing our '65 Wagonaire 283(I was young and stupid, I'm old and stupid now).
It revved up and slammed the shifter into park fortunately. I knew it was the motor mounts because I heard about the recall and we had some sort of book that listed recalls(this was in the late 80's).
I can't remember if the motor new mounts had some sort of safety or not but it can happen to the '65-'66 Studes too.

[JoeHall]

Well the deed is done. It took about an hour to install the chain. With fan shroud, HFI, PS, PB, AC, charcoal can, etc, the engine bay in that GT is kinda busy, and its difficult to even access that area. Grease up to the elbows, but that's what Lava is for. If I had opted to replace the mount, instead of an hour it woulda took more like a day. As for the chain being unsightly, it takes a flashlight to even see it. Not that I worry about an in service looking engine bay anyway. As is, its good to go till the next motor rebuild.
Thanks