C5 Engine mounts

[Rich Z]

After the aborted attempt to buy urethane engine mounts from Hinson Motorsports, I received a tip about a nearly identical product from Creative Steel -> https://creative-steel.com/shop/97-04-corvette-c5-urethane-engine-mount/. Not only were these less expensive, but they also included heat shields as well as mounting nuts for the studs. Of course I am replacing the nuts with stainless steel ones.

These will replace the Pfadt mounts now on the car, as the driver's side one has already failed with the urethane apparently damaged and the upper portion now sitting on the mounting bolt, so there is metal to metal contact with that engine mount. I'm sure that is introducing some notable engine vibration to the car's frame.

Probably won't do this till I decide to replace the clutch, as I will need to pull out the headers at that time, and might as well kill as many birds with one stone as I can.

FYI, what seems to be the easiest way to replace the engine mounts is this:

With the exh manifolds out of the way, remove the mount nuts top and bottom. Jack the engine up just a tad. Remove the 3 bolts from the alum mount on the side of the engine. Remove it and pull the mount out.
Reverse order to reinstall new mounts.

Source: http://www.corvetteforum.com/forums/c5-tech/3008985-replace-motor-mount-how.html

 

[85vette]

When my (second set of) factory engine mounts failed I could actually feel the engine drop back down on the broken mount if I wasn't babying the clutch pedal. I knew what it was as soon as I felt that. Clunky feeling.....not good.

I remember driving a 69 Impala SS that had a broken mount. If you hit the gas very hard at all on a left turn the engine would raise up making the accelerator pedal get stuck at WOT! I turned left from Appleyard Drive onto West Tennessee Street sideways one day after I forgot about that.....pucker factor was high! The brakes were pretty useless at that point.

 

[Rich Z]

Sounds like a change in underwear might have been in order........

I broke the driver's side motor mount in my old '66 GTO, and after replacing the mount, put a length of chain from the frame to the driver's side of the engine to try to keep that from happening again.

At least with the Corvettes, I suppose the torque tube arrangement will keep the engine from moving around too much. But still, I guess the torque could be bad for the torque tube and the rest of the drive train too.

The Pfadt mounts don't look like they will actually separate, as it is just the urethane bushing between the upper and lower parts that looks damaged. I hear that they are pretty susceptible to heat damage from headers, and there was no mention of any sort of heat shield when I bought them. So with these new ones, I intend to not only use the provided heat shields, but also wrap the mounts themselves with reflecting heat tape too.