Checking Engine Mounts

Status
Not open for further replies.
jimmcgee

jimmcgee

.
Feb 26, 2008
603
Catalina 30 Marathon, FL
I have a 1995 Catalina 30 MKIII with a Universal M-25XPB diesel engine.

I'm 90% sure that my rear engine mounts are bad due to the amount of vibration I'm seeing and a resonant noise I'm getting back through the hull.

There are relatively low hours on the cutlass bearing and there was no play in the cutlass bearing when I checked it prior to splashing in the spring.

If I press a boat hook against the starboard rear engine mount while running both the vibration and resonant noise stop immediately; which is why I'm 90% sure one or both rear mounts are bad.

What is the proper procedure for checking one of these mounts to determine if it is either bad, or worn and nearing the end of its life? I checked the Universal Manual, Nigel Calder's book and the C34 Universal engine wiki. There's a lot of information on replacing them, but nothing I can find on checking their condition.

Thanks,
Jim
95 C30 Island Time
 
Stu Jackson

Stu Jackson

.
Feb 26, 2004
22,802
Catalina 34 224 Maple Bay, BC, Canada
It's kinda like reefing: if you think you need to it's almost too late! :)

Given the age of your boat (16 if my math is correct) then you may well be due for a replacement. OTOH, mine are 25 years old and I've chosen to live with the resonance, 'cuz it tells me if the engine is running OK or not. I can FEEL different things and have, over the years, been able to diagnose some things I wouldn't be able to if the engine was as whisper quiet as some I've heard (or not, like one of our skippers who says that friends came over and didn't know his engine was even on!).

You could check the condition of the rubber. If they're dried out and stiff, that's kinda the giveaway.
 
jimmcgee

jimmcgee

.
Feb 26, 2008
603
Catalina 30 Marathon, FL
Stu,
Most of the posts on the C36 forum recommend the Vetus K75 mounts over the stock Universal mounts. Is that because they're better at isolating vibrtation, more readily available or cost less?

BTW, the C36 wiki's are a great resource.

Thanks,
Jim
 
Stu Jackson

Stu Jackson

.
Feb 26, 2004
22,802
Catalina 34 224 Maple Bay, BC, Canada
I don't think the C36 site has a wiki, but we do! :)

The wiki is kinda the tip of the iceberg for our C34 website. It is a collection of past writeups that have stood the test of time.

For more daily Q&A's use the Main Message board and its great search engine. There have been scads of discussions about this subject.

http://c34.org/bbs/index.php/board,11.0.html

Good luck.

The concept of the 75s over the 50s is that they're stiffer.
 
Status
Not open for further replies.

Top Bottom