Should I replace these motor mounts?
1967 Pedal Car Champion
Joined: Mar 2020
Posts: 9,137
Likes: 4,248
From: US-PNW
1967 Pedal Car Champion
Joined: Mar 2020
Posts: 9,137
Likes: 4,248
From: US-PNW
I'm not using either one I got from Rock. The Anchor brand from the local store was better looking as far as quality, from what I can tell. They look very, very similar to the stock GM mounts I pulled from the car - except for the grease-soaked rubber with the crack separation running around the joint.
Last edited by barkingrats; May 15, 2020 at 11:35 PM.
Le Mans Master
Joined: Aug 2017
Posts: 8,336
Likes: 2,810
From: Cool Northern Michigan
As the story goes, customers received a letter from GM corp about bringing their newer vehicle into the dealership as soon as possible.
Also as the story goes, millions of short steel cables were attached to one side of the motor mount of millions of vehicles, "just in case" the mount let go.
Evidently, that satisfied the court system as far as a possible stuck throttle accident liability.
The cable was premade, cheap, minimal time, easy fix. But not a repair.
Also as the story goes, millions of short steel cables were attached to one side of the motor mount of millions of vehicles, "just in case" the mount let go.
Evidently, that satisfied the court system as far as a possible stuck throttle accident liability.
The cable was premade, cheap, minimal time, easy fix. But not a repair.
Last edited by HeadsU.P.; May 16, 2020 at 08:31 AM.
Le Mans Master
Joined: Mar 2004
Posts: 7,500
Likes: 1,508
From: Little Rock AR
When I bought my '69 Camaro back in the late 70's it had a short length of common link chain attached between the drivers side exhaust manifold and the upper a-frame cross shaft. I thought "what the heck is that for"? I immediately removed it and tossed it because it made no sense to me at the time. I went for a drive and punched it.......WEEEEE!!!! Without the home made chain restraint (and obviously a broken mount) the engine torque rotated the drivers side of the engine up and the throttle linkage locked tight in the wide open throttle position. 
I went screaming down the road for a short while until I could shut the key off. JUST WOW! 
The OP has posted a picture of the newer style safety mount that has the interlock feature so if the rubber bond shears, the metal "T" will hold it from releasing all the way. That was the final solution.
I went screaming down the road for a short while until I could shut the key off. JUST WOW! The OP has posted a picture of the newer style safety mount that has the interlock feature so if the rubber bond shears, the metal "T" will hold it from releasing all the way. That was the final solution.
Le Mans Master
Joined: Dec 2006
Posts: 8,837
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When we get to town, I could not slow down. I was standing on the brake with two feet, and I could not stop. Pop turned the key off, and I coasted thru the stop signs into a field.
The dam throttle linkage fell off, or the spring broke, but he understood then I was not punking him.
The good old days.
Drifting
Joined: Dec 2017
Posts: 1,306
Likes: 226
From: PA
1968 or so dad let me drive the 63 Pontiac along the Salton Sea on the old two lane. He let me peg it at 120mph. It was a rolling road, so we were weightless at each crest. My 21 year old brother in back having a fit.
When we get to town, I could not slow down. I was standing on the brake with two feet, and I could not stop. Pop turned the key off, and I coasted thru the stop signs into a field.
The dam throttle linkage fell off, or the spring broke, but he understood then I was not punking him.
The good old days.
When we get to town, I could not slow down. I was standing on the brake with two feet, and I could not stop. Pop turned the key off, and I coasted thru the stop signs into a field.
The dam throttle linkage fell off, or the spring broke, but he understood then I was not punking him.
The good old days.
That would have been about 1972. As Bird says, The good old days. And as Dewey Duck once said, "That's kind of fun once you know you're going to live"
which we did as apparently neither our parents or uncle ever found out 
Team Owner
Joined: Jan 2006
Posts: 39,390
Likes: 171
From: Into the Mystic And yet, despite the look on my face, you're still talking TN
St. Jude Donor '09 thru '25
1968 or so dad let me drive the 63 Pontiac along the Salton Sea on the old two lane. He let me peg it at 120mph. It was a rolling road, so we were weightless at each crest. My 21 year old brother in back having a fit.
When we get to town, I could not slow down. I was standing on the brake with two feet, and I could not stop. Pop turned the key off, and I coasted thru the stop signs into a field.
The dam throttle linkage fell off, or the spring broke, but he understood then I was not punking him.
The good old days.
When we get to town, I could not slow down. I was standing on the brake with two feet, and I could not stop. Pop turned the key off, and I coasted thru the stop signs into a field.
The dam throttle linkage fell off, or the spring broke, but he understood then I was not punking him.
The good old days.
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Dr. Detroit
Joined: Mar 2012
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From: New Braunfels Texas
I'll state this but invite others to chime in if it is incorrect. I was told that if you decide to use solid mounts on the engine you need to use a solid mount on the transmission also.
That said, my original rubber mounts on my '80 have gone 40 years and 90k. I'll replace them next year when I swap out the engine. Given their longevity, I'll just replace them with rubber.
That said, my original rubber mounts on my '80 have gone 40 years and 90k. I'll replace them next year when I swap out the engine. Given their longevity, I'll just replace them with rubber.
Jebby
Thread Starter
Burning Brakes
Joined: Oct 2000
Posts: 878
Likes: 60
From: Minneapolis, MN USA
Thanks for all the feedback - I'm honestly not sure what I should do. It appears clear to use a "rubber" transmission mount. What is the difference between a locking and non-locking engine mount? What was on it originally?
1967 Pedal Car Champion
Joined: Mar 2020
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From: US-PNW
The locking plate rubber mounts would have been factory in '70. Think of a mount as being like an Oreo. Two metal cookies with rubber stuffing. The difference between locking and non is that in a locking mount if the stuffing separates from one of the cookies, the cookies are limited in separating from the trio. You can see the "lock" where the tabs of one cookie are captured between the bends of the other cookie. In your posted pic, you can see the two interlocking bends at the far left of the mount.
Drifting
Joined: Dec 2017
Posts: 1,306
Likes: 226
From: PA
Second, on the rubber, poly, or solid, in my opinion, unless you expect some extreme use that would justify solid, I would go with rubber mounts. I look at it this way, the original rubber mounts on my '80 are are still functional. That's 40 years and 90,000 miles. Should they be replaced? Yes, and they will next year when I swap in a new engine. For basic street driving rodding, they work fine. Some will tell you that they allow vibration. Maybe so, though with everything else rattling in a vette I never noticed it. My own experience with vibration is that when you want to get rid of it, you put something that can damp out the vibration between the part that is vibrating the part that isn't. That something is usually something like rubber. In any case, if you find out you don't like them, even the good ones like those from Corvette Central only set you back a less than $100. So, you can always change them without too much loss.
Instructor
Joined: Sep 2016
Posts: 130
Likes: 49
From: Phoenix, AZ
Replace them. Anytime you do a major renovation you should replace the incidental parts because you can at that time.
Go polyurethane. Trust me on this.
Go polyurethane. Trust me on this.
Last edited by balljointnut; May 17, 2020 at 10:48 PM.
Racer
Joined: Nov 2018
Posts: 295
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From: Toronto Canada
Thread Starter
Burning Brakes
Joined: Oct 2000
Posts: 878
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From: Minneapolis, MN USA