Imco Extreme SC help

[Cigaretteman]

I hope some of you can help me with this question.
After the end of the season 2006 when we put the boat inside for winterstorage I discovered that I have a little bit of sideways movement on my propshafts. If I grab the propeller I can move it form side to side or up and down a little bit and was wondering if that should be possible. The lowers was rebuild 50 hours ago and are running perfect and there are no shavings in the oil at all.
If it is not supposed to be that way what is the procudere for removing this sideways play, can I tighten something or must I have some bearings changed ?

Cigaretteman

[Mr Gadgets]

It depends on the setup. Imco uses shims to set the preload on the two tapered bearings that support the propshaft. Merc uses a crush sleeve. During assembly if the races are not seated properly they can move and loosen the preload. Normally, break in of the bearings doesnt loosen it enough to make the shaft sloppy, it will only turn easier.
So this is something that needs to be fixed. If it was shimmed on assembly, then the proper number of shims need to be removed for proper preload. If it was built with a crush sleeve, it can be tightened up by tighting the retaining nut that is outboard of the bearing carrier. It must be tightened until the proper preload is obtained.
In most cases, someone that has experienced doing it and the proper tools should tackle this to get it right. If it isnt right, more damage will result. And depending on the amount of free play, it may have some consquences. The first thing might be propshaft seals. So if you do just tighten it.. look for water in the oil in future. I have seen the nut tightened and no ill effects. I would take it back to the person that rebuilt it.. It shouldnt loosen up in 50hrs..

Hope this helps
D*ck

[Cigaretteman]

Originally Posted by Mr Gadgets

It depends on the setup. Imco uses shims to set the preload on the two tapered bearings that support the propshaft. Merc uses a crush sleeve. During assembly if the races are not seated properly they can move and loosen the preload. Normally, break in of the bearings doesnt loosen it enough to make the shaft sloppy, it will only turn easier.
So this is something that needs to be fixed. If it was shimmed on assembly, then the proper number of shims need to be removed for proper preload. If it was built with a crush sleeve, it can be tightened up by tighting the retaining nut that is outboard of the bearing carrier. It must be tightened until the proper preload is obtained.
In most cases, someone that has experienced doing it and the proper tools should tackle this to get it right. If it isnt right, more damage will result. And depending on the amount of free play, it may have some consquences. The first thing might be propshaft seals. So if you do just tighten it.. look for water in the oil in future. I have seen the nut tightened and no ill effects. I would take it back to the person that rebuilt it.. It shouldnt loosen up in 50hrs..

Hope this helps
D*ck

Thank you for the answer! My problem is that the rebuild was done in the US and I live in Denmark Europe and have the boat here. The rebuild was done by the seller just before I bought the boat. Can a Mercruiser mecanic handle the job or does it require special tools ? I dont know how big the difference really are between the XR and the Imco.

Thank you.

[monstaaa]

a merc tech trained in i/o's will be able to do it. evrythingd*ck said is spot on.