Float A Motor Front Motor Mount
- Thread starter TinCup
- Start date
dan
Senior Member
My car has float-a-motor front and rear, and I'm thinking about switching them out for stock mounts. Right now the front of my engine sits about 1/2 inch too high and I believe sagging rear FAMs contribute to this, along with the taller replacement springs in the front.
From what I've read, vibrations are actually least with the float-a-motor rears and the stock front, and worst with FAM both front and back. Someone (John Lavoy?) will pipe up with actual experience running both stock and FAM front and rear... I seem to recall that there was some empirical (as opposed to anecdotal) evidence that supports the above assertion.
From what I've read, vibrations are actually least with the float-a-motor rears and the stock front, and worst with FAM both front and back. Someone (John Lavoy?) will pipe up with actual experience running both stock and FAM front and rear... I seem to recall that there was some empirical (as opposed to anecdotal) evidence that supports the above assertion.
Keith True
Well-known member
I have one of those,and two cars with rear FAM's.That front mount was given to me by a guy who insisted it made his car vibrate so bad the mirror was fuzzy.I went to take it outwith him,and found he had the thing installed wrong,with NO rubber under the crossmember,the bolt was riding directly on the steel.I showed him,and said let's put a puck under here to isolate the metal to metal contact.He said no,this is what the directions say and that is how it has to go.He would not accept the idea that the directions were wrong,the design just had to be defective.The directions WERE wrong,and he had installed it just like he was shown.I used it,set it up right,and have had zero problems with it.However,I see no real need for it,the stock mount works fine with no more or less vibration.If you install it wrong you will get terrible vibrations.I used it on a frame with a nice tightly riveted crossmember,with the motor mount hole rusted to about a 2 inch hole.If the engine ever gets pulled I will weld up the hole and fix it,until then this mount is working fine.
Keith True
Well-known member
It sounds as if you have other problems contributing to this.Sagging rear mounts,from bad rubbers or most likely a sagging frame.If the engine is offset to one side the frame could have taken a hit to one rail,dead on in the front and pushed it back a little.It doesn't take much.Then,the stock mounts could have been run with the rubber sleeves wallowed out and the holes in the mount could be egged out letting one side slide back.The frame could be sagging at the drivers side mount,(common) or the whole frame could have a sideways bend.I have seen a lot of that where the car was stuck in the mud and somebody would twitch it out of the ditch kind of sideways and backwards.Suddenly the hood has a vertical gap of over an inch at the rear on the drivers side and no more gap on the passenger side.I have a truck that I put another frame under a couple of years ago.It was perfectly straight.When I got it done with it,and was trying to line up the hood I found it near impossible.With the weight of everything on it the frame had nearly a half inch sag at the motor mounts.Now I have welded a lot of big truck frames together,and have seen some weird stuff,but never this.One of the retired old fellows that taught me a lot of truck frame repair told me that the frame had probably sat around for the last 40 or 50 years,(true)and was most likely bent when left in the shed.Being a very wimpy piece of steel he thinks it reverted back to it's original plane,but without any real character behind it.He thinks that if I had checked it after I had mounted the engine and trans in it I would have caught it then.So after the fact I slit two I beams under the truck,chained them to both ends of the frame,and jacked up under the mount area using a two foot piece of iron as a spreader.When the hood lined up I quit.Seems OK now.