140 hp Mercruiser MC-1 bellows & boot replacement job

[Jim Robbins]

Hi, I think it's time to have the bellows and the rubber boot changed on the stern drive
(don't know the proper name, keeps the wet side away from the dry side)

* Mercruiser 140 hp serial #3129102 (year ?) / Stern Drive MC-1 serial #2073371
What are All the parts required to do this job? What other maintenance to do at this time?
Is it a job that should be done by a Marine Mach.? What would this job cost, parts and labor?
Any & all details would be great. Thank-you

 

[Don S]

Re: 140 hp Mercruiser MC-1 bellows & boot replacement job

Age is probably 67 or 68. No exact info from that era.
The job is a lot of work, rather you can do it or not depends on your mechanical abilities. Many DIYers have done it, but it's not a 5 minute job and it can be confusing.
You need service manual #1, download it HERE
How much it would cost depends on the shops in your area, best to ask them, it also depends on how much corrosion is involved and what all is bad.

 

[Bamaman1]

Re: 140 hp Mercruiser MC-1 bellows & boot replacement job

You'd best to get a professional do the job. The bellows are held on by large hose clamps, and Mercury didn't see fit to put a very large lip on each end for the clamp to hold onto. If not sealed properly, you'll have water contamination in your driveshaft, etc.

A marine mechanic does these type of maintenance repairs often, and they're just better at getting the bellows(s) to seal properly. They can also checkout the condition of the U-joint, etc. at the same time.

While you're at it, you should have a vacuum and pressure check on the lower unit to make sure the seals are intact. Bad seals can be a $300+ repair, and the lower unit gears can be ruined if water gets into them.

And while disassembled, a water pump impeller is something like $27 (cost), and it should be replaced.

Sometimes mechanical repairs just mushroom out.