Breaking motor mounts????
 

I have a 72 satellite with a stock 318. I had just recently swapped the 2bbl out with a 4bbl. During test and tune I thought I would see what it would do and broke the drivers side motor mount. I didnt think too much of it, figured it was an original part and it broke due to age and wear. I was out again trying to fine tune transmission linkage and I broke the new motor mount. The car is a stock 318 (other than the 4bbl), one wheel wonder with a 2:73 gear ratio (had not pulled cover, thats what the tag said and doesnt feel like a lower gear) and has 275/60R15's for tires on the rear. Both times the motor mount broke the tire had gripped and did not spin. I cant imagine with this setup I would be breaking motor mounts and would have the need for solid motor mounts???????

Have you checked all the mounts, ie: tranny etc ?

I hadnt really paid attention to the trans mount, just checked it...the rubber is cracked and deteriated, I tried prying on it with a pry bar but didnt get much movement out of it. I suppose the torque of the engine could make it move enough to put more strain on the LH motor mount. I'll replace them all and see if that makes a difference. Thanks for your input........

No probs man thats why we're here. Let us know the outcome.:D

Will do.......

did you replace both motor mounts when the first one broke?

No, I changed just the broken one. I'm going to change all of them this next time including the trans mount. I tried to save a few bucks.......the older mounts must be flexing enough to put too much strain on the drivers side mount.

thast a good idea 72, the drivers side is called the torque side, it gets more force against it when you rev the motor, it pulls to the right or pass. side. so all the pressure goes to the drivers side.

another idea is the schumacer mounts that are the replacement type. much stronger that the one u get at the parts store.

you always replace both motor mounts
if one breaks, that is a lot of stress on the other one
always replace both

Picture this, factory mounts are two flat plates mounted in rubber, the aftermarket ones have the metal interlinked in a "handshake" arrangement with the rubber between them. If the rubber fails, the metal will still be there to hold it.

I spent $5.00 on the replacement motor mount from Autozone, The term, "you get what you pay for" goes a long way.........

In the trades we used to say "The sorrow of poor quality endures long after the joy of low price is forgotten".

LOL. thast the honest truth scotty.

Chain that torque monster down
 

Get a short piece of chain and eliminate any chances of breaking that new mount by bolting the chain to the block and and to the k-member. Also, you will not have the excessive vibration from the solid motor mounts.

Oil leak?
 

I've heard if oil leaks on them they can deteriorate prematurely.

Another cheap old school means of strengthening the motor mount is to drill about a 1/2'' hole thru the motor mount plates, and put something like a 3/8'' bolt thru that hole. Don't torque it down, just finger tight with some blue lock tight, and you now have an unbreakable mount. You still have your vibration absorption, but the mount won't travel any farther than the length of the bolt.