can someone please give me a little education on the different motor mounts available for midyears ?

the mounts on our 66 are not a matched pair but i don't think either one is the locking type. i'm guessing one is original and the other is an aftermarket replacement.

how likely is an original style mount to fail ? i like to keep things correct/original but not if safety is an issue with them.

after doing a search in the forum and finding some info on a recall long ago on pre 68 motor mounts i'm interested to find out more.

thanks

 

Chevrolet did do a recall for motor mounts that were failing, primarily the driver's side mount, in the late 60's early 70's. At the same time they redesigned the original mounts to incorporate an interlocking mechanism that allowed the mount to absorb vibrations but only move a fraction of an inch should the rubber break loose from the metal brackets. Unfortunately the recall did not require them to install these new mounts. What it did call for was for the dealer to install a short cable with ends that a bolt would slip through. The strap was wrapped around the exhaust manifold and fastened to the bolts that held the upper control arm to the chassis...

You can make your own locking motor mount just as the aftermarket did, by drilling a hole through the center of the stock (new) mount and installing a bolt with a lock nut on it. The bolt looked like this...

You then champer the hole to allow the head to fit flush (head next to the block). Attach the lock nut to the bolt as it comes out of the mount and you now have a safety mount. Very easy solution with the only challenge being to find the correct length bolt. Most hardware stores carry a variety of these in various lengths. I would use at least a 3/8ths bolt and preferably a 7/16ths. The nut doesn't need to be torqued, simply snugged down tight.

Good luck... GUSTO

 

There are still many SB cars out there with the original mounts in them. Don't know about BB's.

I don't believe the Corvettes used the cable restraint. Not sure.

Using the bolt method as described above was an accepatable alternative to using the redesigned factory mount. Id'ing a locking mount is easy. Just look for fingers that will prevent the two metal halves from separating in the event the rubber separates.

 

Here's an easy way to tell:

Floor the gas pedal with the clutch depressed. As the tach passes redline, slip your foot off the clutch. When the tach reaches reline again, lift your foot off the gas. If the engine continues to accelerate, the pedal linkage has jammed in the WFO position due to a broken non-locking motor mount, allowing the engine to torque over.

At this point you'll be wishing you'd bought a Toyota anyway.

 

I still have the original mounts in my 63, Mike. They're still in good shape.

BTW, IF it's your thing, you can still buy "original" non locking mounts.

Chuck

 

The originals are still on my '65 too and also are in good shape. The Corvette mounts and some of the like pass car mounts were tougher than run of the mill mounts that failed.

I also have a car that still has the OEM mounts on it and that car was in the recall bunch. Mounts are still good.

Were the Corvettes even on the recall? I don't have my papers handy to look.

 

Nope. The Corvette wasn't part of the recall, as the throttle linkage on the Corvette didn't hang up and jam at WOT when the mount failed like it did on most of the passenger cars.