Question about filling motor/trans mounts.

**nik12937** · 04-04-2014

So while I had my subframe lowered to get into my transmission (thanks again for writing that guide Bill), I saw my motor mount has finally started to leak and sag a little. I have some new hydraulic mounts that I drilled a while back and forgot about, and now is about time I filled them.

I originally was going to fill them with that window weld stuff like I've seen in a thread before, but it's supposed to cure to a shore rating (hardness) similar to polyurethane mounts. I'd rather fill them with something closer to the rubber the mount is made of though so they still have some give.

Does anyone know what could be used to achieve this? I'm almost thinking black RTV would work, but I'm not sure what shore number I'd really want to aim for.

And how long should I let them cure? Some threads on other forums have said 24 hours is enough, but I've also seen some people say up to a month.

**Turbocharged400sbc** · 04-05-2014

The window weld takes a couple weeks and the rtv takes a few months
if neither is fully cured then you end up with a spaghetti maker when you put the motor down on it

**nik12937** · 04-05-2014

Wow, that's a long time to wait for a mount. I'll just have to bite the bullet and wait until summer to put them in. I don't want to take a chance of having vibrations when I'm stuck in traffic, the blown mount is already bothering me a little.

**Turbocharged400sbc** · 04-05-2014

*****

**Slick2500** · 04-05-2014

I don't know how good the quality of them are but Partsgeek has solid engine mounts for ~$30.

**Turbocharged400sbc** · 04-06-2014

No "solid" mounts are solid...they are hollow with air instead of oil/ water...so they collapse fast as ****.
there really isn't much difference between RTV and the urethane