spannerman
Well-known member
We had a boat in this week with two Mercruiser 4 cyl diesels on B3 drives, it had a horrible rumble from both drives. When we got them off one took what was left of the thrust bearing with it, all the balls were rolling around in the bellows and the other was knackered also.
Result, needs two new complete primary shafts with bearings and U/J's, new thrust bearings and seals, and new bellows.
Luckily the water that had got into the drives wasn't enough to do any damage otherwise he could have been looking at two new drives.
The reason for this damage is the seller who is not a mechanic of any kind but runs a glassfibre workshop told him that the drives don't need to come off for 5 yrs when you replace the bellows!
We always take off a Mercruiser drive at service for this very reason, its the only way to check it hasn't leaked, plus checking motor alignment is part of the service.
So this poor guy has saved on 5 yrs servicing, but now the cost has caught up with him, as the bill will be around £6000.
Result, needs two new complete primary shafts with bearings and U/J's, new thrust bearings and seals, and new bellows.
Luckily the water that had got into the drives wasn't enough to do any damage otherwise he could have been looking at two new drives.
The reason for this damage is the seller who is not a mechanic of any kind but runs a glassfibre workshop told him that the drives don't need to come off for 5 yrs when you replace the bellows!
We always take off a Mercruiser drive at service for this very reason, its the only way to check it hasn't leaked, plus checking motor alignment is part of the service.
So this poor guy has saved on 5 yrs servicing, but now the cost has caught up with him, as the bill will be around £6000.
