What is this??

[special-K]

In all the years I`ve been into these trucks I`ve never had or seen a broken motor mount.They must not have been that bad.

[68gmsee]

I've seen several broken motor mounts on vehicles that I have owned. None caused the problem mentioned, however. I'm glad of that, especially after reading Old Chevy Mech's post.

Usually a broken motor mount can be noticed or seen when revving the engine in park or neutral. I have the originals on one of my trucks and I've checked them in the past. However, after reading all of these post, it wouldn't hurt to check them more often.

[Old Chevy Mech]

It was a long time ago, and I honestly dont remember the specifics of the mounts. If they were new or used, I dont recall. I do know that it never happened again in any of my trucks, so it could have been a fluke. Scared the beejeezes outa me, but not enough that I'd ever part with my Blazer or Pickup!!

Frank

[Longhorn Man]

frank, your story is the exact reason they did the recall and retro fit. And with as cheap as GM is when it comes to recalls, you know it was an issue for them to do it in the first place.

[special-K]

Makes you wonder why they are so rare to find.I`ve seen them go bad and let the motor rock,on any random vehicle.They do go bad.But,can honestly say it`s such a rare occurance on these trucks that I don`t know of any stories until now.I`ve ran 450 hp motors with them,seen diesels mounted to them,and known of wreckers as well as other heavy haulers that dodged this bullet.Maybe there was a bad batch that never got to this area.I know it wasn`t widespread enough for many trucks to have it or for many bad stories.Then,there`s the past 35 years putting proof in the pudding.I`ve had several truck with original motors sitting on their original mounts with mount still in serviceable condition.

[Old Chevy Mech]

I remember the next morning telling my Dad what happened, and he said "Thats strange". Asked me how I got home and if there was anything broke, I told him no, just the mount. Told me to go get a new one off the shelf and replace it before driving it.
Never heard another word about it again, or since then (about 1983). Seeing that strap thing kinda jarred the memory bankks! LOL

Frank

[68gmsee]

GM's fix reminds me of a comment my old uncle used to say re: some vehicles. (Can't remember which ones)

"They sell them with a roll of duct tape and baling wire in the glove compartment."

[nightmare]

I had to do something similar on my '91 GMC Sonoma. I replaced the broken mounts twice before I "fixed" it. Instead of mounting something to the frame, I wrapped a length of 3/16" cable around the mount on the engine, and the frame itself, and bolted the cable together. It was a V6, but with a standard, and 3.73 gears, that thing would move.

I know mounts get fatigued with time, but hot rodding it only speeds that up exponentially.

[Brock]

Originally Posted by too much stuff

Factory engine hold downs. If the motor mount broke, that would hold it in place. Didn't need to be on both sides as the torque from the engine would only lift it one way...
I have seen most of these on 67-68 models.

I've broken two motor mounts in my dirt track car (actually one broke and the other the bolts backed out of the block)...Both were the driver's side and the motor torqued up so far it hit the hood. the second time it actually pulled the trottle cable to the point the motor stuck wide open...definite attention getter!!! So I agree on it being a Motor "tie-down".

[Longhorn Man]

the ex had a poS-10 blazer with the 4.3 CPI vortec... the left motor mount was broken for a long time. If you had it in drive, and was rollin down the road, just jab the throttle twice, the shifter would pop into overdrive. (automatic) When the tranny mount let go, then the sucker would bump the hood.

[67ChevyRedneck]

I got a set of v-8 motor mounts from a junkyard (stands and mounts) out of a 71/72 five or six years ago. Installed them in my truck with the newly installed V-8, and went for a test drive with the hood off. The first time I cracked the throttle open hard I saw the engine just about jump out of the engine bay I figured it was just 35 year old mounts. \

I also had an 86 camaro that the tranny mount broke on, it thumped the floor when you hit the throttle (well, what little throttle a 305 had), scared the piss out of me the first time it did that. It was really loud when it smacked the floor.

The reason for some trucks with them on one side and some on both could be as simple as some dealers are lazy or cheaper than others and only saw fit to install them on the DS.

[68 50th]

Here's a couple pics I saved at some time.
Sorry, don't have any better res pics.

[special-K]

It is a good safety feature,reguardless of how many ever broke.Because when they do...WHOA NELLY!!!!That``s why you see motors plated in with high HP drag cars.I`ve seen guys run a chain for "what if",too.

[original_balzer]

Cool stuff, those diagrams.

Not a GM but I had a 85 jeep grand waggy that the previous owner had swapped in a mild built 401. I had it out bashing the rockers in on some boulders. I was climbing a small but steep hill in 4 low. Suddenly out of the blue all hell broke loose and I went FLYING over the top of the hill (literally caught air). the motor mount had broke and the engine twisted pinning the throttle wide open. That was a hell of a scare. I didnt even know what had happened till later at home I figured it out rev'ing the engine in neutral.

[Stocker]

I had an eye-opener back in '68 in my '65 Corvette, a fairly strong runner with a 327/365 (same as a fuelie but with a Holley & high-rise). Launched it hard and the throttle stuck wide open -- it released after I hit second gear, but it was exciting for a moment... found out later it had a broken motor mount. I remember hearing that was one reason they started using throttle cables (instead of linkage).

[seacrow]

Here is that safety recall strap setup as installed. this is on a 68 motorhome that I am parting out. The driver side was bolted to the manifold and through that frame bracket, the pass side was bolted in this case to the AC compressor and used the tower as a bracket. I had never seen these either.

[Willys47]

was this just a problem on small blocks does any one have picture of how the fixed this problem with the big block motors?

[eagleuh1]

Seacrow, that is exactly how my 68 c20 with 327 was mounted. Passenger side under the engine mount tower to the AC bracket, driver from frame loop to the exhaust manifold at rear. Removed when installed headers after engine rebuild.

[Dark Knight]

Those torque straps were only used on the trucks with the Corvette option. The stock motor mounts couldn't handle the monster torque of the 454 SS.

[71tahoe]

Originally Posted by msgross

makes me wish I bought those Prothane mounts and not the "made in India" ones now.!

All the chevy motor mounts I've bought new (1990 and later) have interlocking metal plates with the rubber isolater sandwiched between. If the rubber fails, the plates catch limiting movement. No chance of major failure unless your torque can shear off the steel tabs. Then you would probably destroy the retrofit bracket on the exhaust with that much torque too.

[Old Chevy Mech]

Originally Posted by 71tahoe

All the chevy motor mounts I've bought new (1990 and later) have interlocking metal plates with the rubber isolater sandwiched between. If the rubber fails, the plates catch limiting movement. No chance of major failure unless your torque can shear off the steel tabs. Then you would probably destroy the retrofit bracket on the exhaust with that much torque too.

No Kiddin..(Not that I doubt you) but I am going to have to cut one apart to see that.

Frank

[bmfpeterson]

i have had a couple recalls on some newer trucks and did nothing about it, one was a tail gate strap and somthin else. maybe thats why there are not that many of those torque straps because most people would not do anything about em! just my opinion

[71tahoe]

Originally Posted by Old Chevy Mech

No Kiddin..(Not that I doubt you) but I am going to have to cut one apart to see that.

Frank

That's a really good idea. My memory isn't what it used to be and it's way too cold to go look at one for a couple of days.

[pritch]

This thread stirred up memories of my '68 Nova when I was in high school. That thing would break the driver side motor mount about every 3rd or 4th time I would really hit it. It wasn't nothing special, just a good strong 327 and a three speed tranny. Factory 3ott, but a PO had converted it to a nice Hurst floor shifter. But it was a motor mount breakin' sunny beach.

[71 super]

I have never seen one on a bb truck, but several years ago the part number for the limiting straps was still in the GM computer system as a good number. I robbed the loop tht mounts to the frame on the drivers side and mounted the strap to the rear bolt hole in the head of my 402, because I thought the strap was a good idea. I had a friend (elderly gentleman) who had a 69 truck that mount broke on and pinned the throttle rod in the wide open position, he hit a telephone pole and totaled the truck. The primary reason for Gm going to a throttle cable setup was because of this problem.