: Motor Mount project

09-26-11, 05:10 PM
Hey Guys, Im getting tired of breaking front motor mounts in my 98 sts with a lightly cammed northstar in it. So My ADHD Mind Got to thinking of a way to fix this mount problem. While Looking at the mount with it in my hand some of the light hydraulic fluid dripped out.

Then it hit me, shouldn't replacing the fluid with something denser that wont leak out fix the problem? But what could I put in the mount that wouldn't leak out but also seal the gaping crack in the rubber. Hmmmm tic, toc, tic, toc, tic, toc, DING DING DING. Fill the sucker up with silicone sealant and letting it cure for a week or two locking the little piston inside the mount in place. Creating a solid mount.

So thats what I did I drilled two holes in the side of the mount so I could drain the remaining fluid and pour a little degreaser in it. I then cleaned it real good rinsing through the holes i drilled until the water ran clean. I left it in the sun to dry for a couple of hours. Then I filled it with silicone rtv that comes in the tube that fits a caulking gun until it came up through the top crack on the mount. I wiped the excess and filled it a little more untill i couldnt get any more in with out it coming out the cracks. will it hold ? Who knows its in the back yard curing. I cant wait to put it on and give it a try. i took pics but I have to find the camera cable resize them the post them

What ya think guys?

09-26-11, 07:22 PM
295 ft/lb of WOT torque on caulking gun silicone.........you really need solid rubber or polyurethane shock mount stuff with a steel tube core. Your idea may hold for a while..........

Did you consider the possibility of filling the solvent-cleaned mount boot with slow curing epoxy putty mixed to about the consistency of sour cream so you could use a WEST system syringe to inject it ? Solid mount.

09-26-11, 10:13 PM
Or make a set of torque struts and you'll never have to change it again.

09-27-11, 04:20 AM
I was thinking it would hold because after all it was filled with oil. which once the rubber at the top was torn it easily flow out loosing the damping that it provided. the silicone would at least compress but not flow out . Heres a image that closely resembles our style of mount http://www.freepatentsonline.com/6663090-0-large.jpg

09-27-11, 04:01 PM
I checked the mount out today and it definitely feels stiffer than a new factory mount. im gonna give it a couple more days to cure then Ill put it to the test. Ill post pictures in a few

09-27-11, 10:47 PM
Somehow I just don't think it's gonna hold, but I'll be interested to hear the outcome. Good luck.

09-30-11, 03:43 PM
Well I couldn't wait and since i was under the car already tracking down a problem with my rack and pinion. i decided to change the mount. Its only been in there for one day now but I think its gonna hold up with no problems. I do have a little bit of vibration transferred from the engine which i can deal with, but also remember I have aftermarket Camshafts installed . I also noticed much better throttle response. I keep you guys updated if anything changes. but so far it works :cool:

johnny kannapo
10-03-11, 01:20 PM
If the mount is fluid filled it is then a pressure vessel and silicone is too soft and will tesar or rip not having a variable compression effect.

They do make a compound that they use in place if air in tires for forklifts & other specialty apps that may fair better but I would use 3M windshield gasket cement for a heavy duty strong bonding & stiff yet pliable filler.

01-12-12, 12:10 PM
See this topic

01-12-12, 01:57 PM
See this topic

This suggested thread ^^^ also has nothing to do with either strut rods or motor mounts..............(yes, there's a picture of an early Northstar dog bone)