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Driver Side Motor Mount

Dee23

Dee23

New member
Hey guys, we all know that 3800's are torque monsters from the factory(for the most part) and definately if your moddified decently. Now im 270whp(for now) and most of you guys have long surpassed this WHP already. I wanna know if you've ever experienced what im experiencing now.

The problem is, in reverse(only reverse) theres a crazy knock. Dead stop, hill or not, big or small load, I tap the gas and the motor looks like its swinging on a swing. I mean thats how much it moves, but it hasnt always done that.

I know its a mount, but the tranny & motor mounts are only 5 months old and the dogbones are no more than a month old (all are GM dealer ship mounts). Now im sure most of you are putting down more torque than me so have anyone ever heard this knocking sound(in reverse or forward)?

Mounts may be defective, but I swear I've went through about 8 tranny/engine mounts between the two bc something was wrong with them so i'll be damned if i have to change another(I will if i have to).

Honestly, I wanna fabricate a mount to sit right on the back of the motor or somewhere bc these motors could actually use it especially with the extra power we're adding to it(I know the motor has to move a bit but it could be a lil more stiffer). At the end of the day GM couldve secured these motors a lil better, especially the SuperCharged ones.

Any thoughts???
Thanks, Dee.....
 


have you flipped the dog bone mounts yet? that firms the engine up a lot. you said new from the dealer, so i assume stock mounts.

and if it didnt move like this after all the new mounts were installed, either a dog bone mount broke or a mount blew on ya.
 
yeah the sway is flipped and the radiator mounts are poly(3800performance). I think the rad poly mounts may be shot a lil. But its only in reverse when i here this crazy knock on the driver side so it may very well be the motor mount again. you guys get any knocking sound?
 
i did when my motor mount was blown to crap.

new motor mount and trans mount, and flipped dog bones, and shes been solid since.
 


Maybe the motor mount is just loose and not properly torqued. Whats the torque spec on the motor mount?

Also, if you guys know the torque specs for tranny mount and torque mounts that'll be great too. I think my mounts are overly tightened or just to loose
 
i just made them all tight. i dont think you can over torque them unless they snapped off when putting them on.

if i were you id put the car on ramps, then get under it and have someone shift it while you watch whats going on. the mounts are the only thing holding the engine in place, so one has to have a problem.
 
Yeah, i had my car on the lift 3 times last week doing the load test. The motor moves a lot on the passenger side. We found the dogbones allowed to much movement so I changed them. Less movement up top now, but still incredibly to much movement bottom right passenger side. Im leaning towards the motor mount once again...Fuucckk

Funny thing is, the 3rd motor mount out of the five i've installed I actually over torqued that one and snapped the stud right off. I've been at war with these mounts for the longest....
 
Most likely the drivers motor mount, if it's one of the hydraulic filled POS's I've had them go out on me in under a month.
 


There is a extreme way if you wanted to spend the time to do it. I do not have any dog bone mounts now because i did not like the way they covered the front rocker cover. I made two rear mounts one from the diff to the frame and one from the xmission driver side this is how the transmission is mounted in other cars IE: cads I have a aluminium cradle but the steel would just as well. It did make a little more vibration in the sterring wheel but not bad. You can see pics at JohnK4 on photobucket or here is a link I think not too sure how to post a link http://i1091.photobucket.com/albums/i383/johnK4/GTX Pace car replica/Eng/913e8564.jpg
 
I wish it was the tranny mount, i'll change that in 5min. Motor mount in about 15min but thats only if the motor falls back into place on the first try, LOL.

My mount was a solid GM mount like my last two and they all had fluid in them(including the ones on my LS too). They're just hydraulic filled mounts but they claim they're solid all the way through.

I swear after market mounts have been on my to do list forever. Personally i think the torque mounts are positioned perfectly(for the most part) for these torqued motors. Dodbones or not, these motors could definately use some strong mounts on the bottom rear. I mean theres one on the driver side, passenger side, two dogbones up front, but GM totally forgot about the backside of these motors
 
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