Front mount check

[jszuba]

Hi!
Is there a way other than visually to check the front mount for wear and tear?

You know... when looking at the top of the mount one can see the bracket around the bushing - the vertical thing in the centre that sticks out and goes around (the bone itself I think).

When I push the bracket from side to side I get a bit of deflection without having to use too much pressure from my thumb.
So, would that mean my mount is shot?

I'm asking because I get vibrations at low rpm, and I have recently replaced my rear mount...

[Asimo5767]

My front mount is shot, and mine vibrates quite a bit, even though my other mounts are good. If you can move it with your thumb then it is probably shot. Just take a close look at the top bushing and look for cracks or tears in it.

[deevergote]

It should have a small amount of flex, but not much. The top part is the only part that goes bad, normally. Removal is the best way to check, but if you can move the mount around on the rubber easily, it's probably done.

You could pull it out and fill it with a liquid urethane. It will make it stiffer than stock and reduce wheel-hop (though the vibrations will increase slightly).



The rear mount is most responsible for vibrations. The side mounts are next. The front mount is really just a torque mount, and doesn't really support the engine. A really bad front mount will be noticeable by the feeling of your engine moving when you shift. Even then, not so much. The turbo guys don't even use the front mount (no clearance with the turbo!)

If you just replaced the rear mount, you might simply be feeling increased vibrations because the mount is new, and therefore stiffer.

[lo-specials]

It should have a small amount of flex, but not much. The top part is the only part that goes bad, normally. Removal is the best way to check, but if you can move the mount around on the rubber easily, it's probably done.

You could pull it out and fill it with a liquid urethane. It will make it stiffer than stock and reduce wheel-hop (though the vibrations will increase slightly).



The rear mount is most responsible for vibrations. The side mounts are next. The front mount is really just a torque mount, and doesn't really support the engine. A really bad front mount will be noticeable by the feeling of your engine moving when you shift. Even then, not so much. The turbo guys don't even use the front mount (no clearance with the turbo!)

If you just replaced the rear mount, you might simply be feeling increased vibrations because the mount is new, and therefore stiffer.

What kind of vibrations are we talking about?
A lot of shaking with accelerating and with taking a right turn, this after doing an auto to manual swap?

[johnl]

The upper bush is OK if the webs aren't ripped through or partially through (I'd be very surprised if the lower bush were bad, it's pretty robust).

Mine is shot at the upper bush, which is quite soft in any case due to the voids in the rubber. With my bush I've cut some pieces of thick fabric re-inforced rubber (might be old converyor belt rubber, just found it somewhere) and rammed them tightly into the voids to take up the slack (not pretty but it works a treat!). I'd bet the bush is now stiffer than stock, despite the webs being half torn through.

I also have a piece of this rubber in the rear mount, but it's very hard to access and I can't can't fill all the voids without removing the mount, which is a pain the arse, sometime...

To check your mounts; put the engine in 1st gear with the handbrake off, then go to the front of the car and vigorously push / pull it backward and forward trying to load up the engine mounts while you watch for excessive motion (engine rocking). If any mounts are substantially shot you should be able to see the engine rock excessively.