When to replace motor mounts?

[Daddyo]

How do you tell if your motor mounts need replacing? My mounts are 25 years old on my 120 Lehman.

 

[Daddyo]

How do you test them with a pry bar?

 

[Marin]

Daddyo---

You may have seen this already where you asked the question in the general information forum but if not----

The rubber bushing in the mount compresses to the point where there is metal-to-metal contact inside the mount. So what you see is the upper disk of metal "collapsed" down inside the "cup" of the lower mount. The rubber inside the mount just looks "flat." Not much of a description, I guess, but that's the best I can do based on what our mounts looked like before we replaced them.

 

[Chris Foster]

Another way to check how the mounts are doing is to check the shaft alignment (assuming it hasn't been readjusted in the recent past).* If you disconnect the transmission from the prop shaft and they're still in good alignment, the motor mounts haven't sagged and are still happy.* If not, before realigning, replace the mounts.

However... you will need to do the whole engine/shaft alignment process two times if you do so (once at installation and again after a few hours when the mounts settle a bit).