Random question about motor mounts - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Ultrasummer · 03-25-2020, 11:55 PM

So I pulled the engine out of my 1968 C10 today. When looking at the 2 motor mounts toward the front of the truck, They appear to be different from each other. Could this be that because of the torque or rotation within the engine one is more stout than the other? Or could it be someone's been in here before and didn't care if they were both the same or not? Everywhere I look for buying new ones...they both look the same. For that matter, is there a left and a right?

**LockDoc** · 03-26-2020, 12:18 AM

Quote:

Originally Posted by Ultrasummer

So I pulled the engine out of my 1968 C10 today. When looking at the 2 motor mounts toward the front of the truck, They appear to be different from each other. Could this be that because of the torque or rotation within the engine one is more stout than the other? Or could it be someone's been in here before and didn't care if they were both the same or not? Everywhere I look for buying new ones...they both look the same. For that matter, is there a left and a right?

They are the same. One of them has been replaced. GM had a problem with the early ones coming apart and letting the engine roll to one side and holding the throttle in the wide open position. They changed the design so that even if they came apart the engine could not roll one way or the other. You probably have one of the old design and one of the new design.

LockDoc

mr48chev · 03-26-2020, 12:43 AM

I can agree with what Lockdoc said but may be as simple as two different brands of mounts installed at different times.

I'm not sure of exactly when GM changed the Chevy mounts so they had the fingers that would keep the left side of the engine from lifting under torque if the mount broke. Anyone who has been though that with a solid rod throttle linkage rather than cable will tell you that the throttle sticking wide open wasn't fun and that was usually what happened when the engine lifted up.

Ultrasummer · 03-26-2020, 02:17 AM

well I appreciate the insight. I'm constantly learning new things on this site about these fun old trucks. Thank you

**'68OrangeSunshine** · 03-26-2020, 02:31 AM

Quote:

Originally Posted by Ultrasummer

So I pulled the engine out of my 1968 C10 today. When looking at the 2 motor mounts toward the front of the truck, They appear to be different from each other. Could this be that because of the torque or rotation within the engine one is more stout than the other? Or could it be someone's been in here before and didn't care if they were both the same or not? Everywhere I look for buying new ones...they both look the same. For that matter, is there a left and a right?

Actually it depends on what engine you pulled.
What are we talking about here? V8, L6, V6?

Ultrasummer · 03-26-2020, 10:21 AM

Quote:

Originally Posted by '68OrangeSunshine

Actually it depends on what engine you pulled.
What are we talking about here? V8, L6, V6?

The engine in question was a 1968 307.

**HO455** · 03-26-2020, 11:26 AM

They are several versions for sale currently. The link below show two of them.

http://67-72chevytrucks.com/vboard/s...d.php?t=773824

**'68OrangeSunshine** · 03-26-2020, 03:36 PM

Quote:

Originally Posted by Ultrasummer

The engine in question was a 1968 307.

OK. Thanks for responding. V8s in my limited knowledge of them have symmetrical mounting, so the pads should be the same.

68Gold/white · 03-26-2020, 03:48 PM

Try to get the ones in 455HO's post that he recommends. There are even different looking preferred mounts that other likely sell. The key is having the 2 steel plates interlock so the mount doesn't come apart. Having some sort of restraint on the drivers side of the engine helps...

Wrenchbender Ret · 03-26-2020, 04:13 PM

There was a huge recall back in the 70's for that reason. GM put cables on the engine & wrapped them around the upper control arm shafts. They didn't replace the defective mounts but the cables kept the engine from rotating too far. I was driving one onetime when it did this. The throttle was wide open & it pulled the power brake check valve out of the booster. Luckally I knew about this & turn the key off. The engine flopped back down.
I was going up hill so I didn't have trouble stopping. Scary!

George

**70STOVEBOLT** · 03-27-2020, 09:03 PM

The same thing will happen on a 250. It happened to me going down the highway once and I turned off the key and coasted to the side of the road, raised the hood and did not see anything wrong. Short time later I was pulling out of a parking lot onto a state road and I got on it to get moving quickly and the fan rubbed the shroud and made a loud noise and I let off and I felt the motor drop back onto the mount. I knew what it was then and replaced the broken motor mount and all was good again.

**FirstOwner69** · 03-28-2020, 11:43 PM

Quote:

Originally Posted by Wrenchbender Ret

There was a huge recall back in the 70's for that reason. GM put cables on the engine & wrapped them around the upper control arm shafts. They didn't replace the defective mounts but the cables kept the engine from rotating too far. I was driving one onetime when it did this. The throttle was wide open & it pulled the power brake check valve out of the booster. Luckally I knew about this & turn the key off. The engine flopped back down.
I was going up hill so I didn't have trouble stopping. Scary!

George

You may be interested in the recall letter. I also had a '65 Impala SS with a 4-speed. I broke a mount when slamming into 2nd about 1967. Luckily the throttle rod didn't bind.

Ultrasummer · 03-29-2020, 12:09 AM

Interesting piece of history you've got there. By now I've already ordered my motor mounts from LMC. They wouldn't sell them if there were prone to failure.....do you think? They are the stock mounts for my year. 1968

**HO455** · 03-29-2020, 01:53 PM

I can't speak as to which style or quality of mount LMC sells it but the one that failed holding the generic 350 in my Burban was a NAPA mount with only several thousand miles on it. NAPA had several part numbers listed but only one was in stock and being in a hurry I was just happy they had them.
I recommend you look closely at the mounts you receive and compare them to the the pictures in my link above.
For my full post scroll down to post 412 here.

https://67-72chevytrucks.com/vboard/...698377&page=17

Ultrasummer · 03-29-2020, 02:20 PM

Thanks for that info. I wonder....is it the center bolt that rips thru the rubber and now everything is free? I've seen some that have the metal plate on both sides, sandwiching the rubber or polyurothane. A bolt couldn't pull thru the sandwiched type. I'm not sure. I've already ordered from LMC but I may have to order better ones and send LMC's back.

**HO455** · 04-02-2020, 10:42 AM

Photo of how mine tore apart.

03-25-2020, 11:55 PM	#1
Ultrasummer Registered User Join Date: Mar 2018 Location: Fort Wayne Posts: 106	Random question about motor mounts So I pulled the engine out of my 1968 C10 today. When looking at the 2 motor mounts toward the front of the truck, They appear to be different from each other. Could this be that because of the torque or rotation within the engine one is more stout than the other? Or could it be someone's been in here before and didn't care if they were both the same or not? Everywhere I look for buying new ones...they both look the same. For that matter, is there a left and a right?

03-26-2020, 12:43 AM	#3
mr48chev Registered User Join Date: Jul 2007 Location: Toppenish, WA Posts: 15,435	Re: Random question about motor mounts I can agree with what Lockdoc said but may be as simple as two different brands of mounts installed at different times. I'm not sure of exactly when GM changed the Chevy mounts so they had the fingers that would keep the left side of the engine from lifting under torque if the mount broke. Anyone who has been though that with a solid rod throttle linkage rather than cable will tell you that the throttle sticking wide open wasn't fun and that was usually what happened when the engine lifted up. __________________ Founding member of the too many projects, too little time and money club. My ongoing truck projects: 48 Chev 3100 that will run a 292 Six. 71 GMC 2500 that is getting a Cad 500 transplant. 77 C 30 dualie, 454, 4 speed with a 10 foot flatbed and hoist. It does the heavy work and hauls the projects around.

03-26-2020, 02:17 AM	#4
Ultrasummer Registered User Join Date: Mar 2018 Location: Fort Wayne Posts: 106	Re: Random question about motor mounts well I appreciate the insight. I'm constantly learning new things on this site about these fun old trucks. Thank you

03-26-2020, 11:26 AM	#7
HO455 Post Whore Join Date: Feb 2016 Location: Portland Oregon Posts: 11,023	Re: Random question about motor mounts They are several versions for sale currently. The link below show two of them. http://67-72chevytrucks.com/vboard/s...d.php?t=773824 __________________ Thanks to Bob and Jeanie and everyone else at Superior Performance for all their great help. RIP Bob Parks. 1967 Burban (the WMB),1988 S10 Blazer (the Stink10 II),1969 GTO (the Goat), 1970 Javelin, 1952 F2 Ford OHC six 4X4, 29 Model A, 72 Firebird (the DBP Bird). 85 Alfa Romeo If it breaks I didn't want it in the first place The WMB repair thread http://67-72chevytrucks.com/vboard/s...d.php?t=698377

03-26-2020, 03:48 PM	#9
68Gold/white Registered User Join Date: Sep 2011 Location: Ark City, Kansas Posts: 3,324	Re: Random question about motor mounts Try to get the ones in 455HO's post that he recommends. There are even different looking preferred mounts that other likely sell. The key is having the 2 steel plates interlock so the mount doesn't come apart. Having some sort of restraint on the drivers side of the engine helps...

03-26-2020, 04:13 PM	#10
Wrenchbender Ret Registered User Join Date: Oct 2005 Location: Overland Park, Ks. Posts: 5,207	Re: Random question about motor mounts There was a huge recall back in the 70's for that reason. GM put cables on the engine & wrapped them around the upper control arm shafts. They didn't replace the defective mounts but the cables kept the engine from rotating too far. I was driving one onetime when it did this. The throttle was wide open & it pulled the power brake check valve out of the booster. Luckally I knew about this & turn the key off. The engine flopped back down. I was going up hill so I didn't have trouble stopping. Scary! George

03-27-2020, 09:03 PM	#11
70STOVEBOLT Senior Member Join Date: Jun 2005 Location: Winona Lake, IN Posts: 6,259	Re: Random question about motor mounts The same thing will happen on a 250. It happened to me going down the highway once and I turned off the key and coasted to the side of the road, raised the hood and did not see anything wrong. Short time later I was pulling out of a parking lot onto a state road and I got on it to get moving quickly and the fan rubbed the shroud and made a loud noise and I let off and I felt the motor drop back onto the mount. I knew what it was then and replaced the broken motor mount and all was good again. __________________ 70 C/10 SWB 402/TH400/3.73 "The Needy Beast" 200,000 Mile Club Disc Brake Club Owner installed options: Front Sway Bar Power Steering Power Brakes Cigar Lighter Courtesy Lights Deluxe Side Markers Wiper Delay Power windows Power Locks Sniper EFI 2015 Silverado 1500 LS 4.3/6L80/3.23 lowered 2" front & rear

03-29-2020, 12:09 AM	#13
Ultrasummer Registered User Join Date: Mar 2018 Location: Fort Wayne Posts: 106	Re: Random question about motor mounts Interesting piece of history you've got there. By now I've already ordered my motor mounts from LMC. They wouldn't sell them if there were prone to failure.....do you think? They are the stock mounts for my year. 1968

03-29-2020, 01:53 PM	#14
HO455 Post Whore Join Date: Feb 2016 Location: Portland Oregon Posts: 11,023	Re: Random question about motor mounts I can't speak as to which style or quality of mount LMC sells it but the one that failed holding the generic 350 in my Burban was a NAPA mount with only several thousand miles on it. NAPA had several part numbers listed but only one was in stock and being in a hurry I was just happy they had them. I recommend you look closely at the mounts you receive and compare them to the the pictures in my link above. For my full post scroll down to post 412 here. https://67-72chevytrucks.com/vboard/...698377&page=17 __________________ Thanks to Bob and Jeanie and everyone else at Superior Performance for all their great help. RIP Bob Parks. 1967 Burban (the WMB),1988 S10 Blazer (the Stink10 II),1969 GTO (the Goat), 1970 Javelin, 1952 F2 Ford OHC six 4X4, 29 Model A, 72 Firebird (the DBP Bird). 85 Alfa Romeo If it breaks I didn't want it in the first place The WMB repair thread http://67-72chevytrucks.com/vboard/s...d.php?t=698377

03-29-2020, 02:20 PM	#15
Ultrasummer Registered User Join Date: Mar 2018 Location: Fort Wayne Posts: 106	Re: Random question about motor mounts Thanks for that info. I wonder....is it the center bolt that rips thru the rubber and now everything is free? I've seen some that have the metal plate on both sides, sandwiching the rubber or polyurothane. A bolt couldn't pull thru the sandwiched type. I'm not sure. I've already ordered from LMC but I may have to order better ones and send LMC's back.

04-02-2020, 10:42 AM	#16
HO455 Post Whore Join Date: Feb 2016 Location: Portland Oregon Posts: 11,023	Re: Random question about motor mounts Photo of how mine tore apart. Attached Images __________________ Thanks to Bob and Jeanie and everyone else at Superior Performance for all their great help. RIP Bob Parks. 1967 Burban (the WMB),1988 S10 Blazer (the Stink10 II),1969 GTO (the Goat), 1970 Javelin, 1952 F2 Ford OHC six 4X4, 29 Model A, 72 Firebird (the DBP Bird). 85 Alfa Romeo If it breaks I didn't want it in the first place The WMB repair thread http://67-72chevytrucks.com/vboard/s...d.php?t=698377



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