What Outdrive am I most likely to have/Clanking sound

T

TXVR6

New Member
Dec 14, 2007
27
Hi guys. I have gone through my paperwork and can't find anything relating to the outdrive. I'll go out on a limb and assume its the original. I know it was rebuilt last year. I have the Merc 350 260HP so would that be an Alpha One?

It was painted the last time the bottom was done so I can't see any decals. I don't currently have a way of pulling it out of the water either.

When I turn sharp in either direction going either forward or in reverse it makes this clanking sound. It does not do it during normal maneuvers but only when I'm turning sharp to leave or back into the slip. The previous owner said he asked about it when it was rebuilt the last time and was told that was common for that model. :huh::huh:

Sounds like BS to me but he has 30+ years of boating experience to my 8 months so I didn't say anything. It apparently didn't bother him enough for him to do anything about it and he was out in the boat 2-3 times a week until selling it to me. Thinking back he may have said it was making that noise before the rebuild. I can't remember.

It sounds horrible but apparently has been doing it for a while.

Any ideas of what it could be?

Thanks.
 
1979 might even be pre alpha, sounds like ujoints to me, put in bind when you turn hard right or left. If it is fine in normal running conditions it may be normal for that unit. My 04 Alpha, gen 2 will make noise if turned all the way to the stop right or left.
 
I don't know for sure but my friend told me to stay away from rebuild outdrives/engines b/c when they are put back together they can't get the gears or driveshaft or whatever it is to mesh back together as well as they originally did.

It sounds like when you are turning the outdrive it is slipping off whatever connects the outdrive to the engine maybe? Do you lose power?

My friend explained this to me when I was buying my boat a year ago so forgive my vagueness (spel).
 
In a 79 you probabaly have the pre-Alpha drive model 1R. That's what I have in mine. If you can get the serial off the drive I can confirm that for you.
 
A rebuild done correctly will bring everything back to factory specs and should run as good as a new one for less money. If the housings/engine blocks are not damaged you can rebuild, there are times that you want to go with a factory reman instead of rebuilding it just depends on the situation at the time.
 
Yea, what is this notion that you can't rebuild a drive. I have heard others say that also. While I have not attempted it, I have done a lot of rebuilds in the automotive world and there are not many things that are not rebuildable. I would think that if the housing is in good shape, and the internals were not destroyed any drive would be a good rebuild candidate.
 
I had my pre-alpha 1 drive rebuilt last year. everything works good. No noises while turning, etc. It was a complete rebuild, i.e., gimbal, shafts, impellar, et al. completely satisfied with the work done by the certified Merc. mechanics.

Something doesn't sound right if it still makes an unsettling noise while turning.

My .02

Gregg
 
I would definately pull the boat and take a look at it. If you have a fair amount of auto axperience you will have no problem pulling the drive. Rebuilding is another story. The shaft has a u joint (just like the drive shaft on your old car) that will be visible when you pull the unit. It is very common for them to wear out. Even faster if you run your drive with it trimmed way up. Hard turns are tough on the units also. If you keep using this without checking it , you could end up with a big expensive mess. There could be a plethora of other things wrong, but giveb the info you gave, It is possible it is the joint. They dont last forever and checking them should be annual maintenance if you use the boat with regularity. If that isnt the problem, you have completed step one for the mechanic. There is a problem though, there should not be noises coming from your drive.
Phil
 
Probably an I-R drive. It fortunately has been several years since I looked at sterndrive stuff, but I think that you can identify this drive by the preload pin at the top of the intermediate drive shaft. That is the vertical shaft that runs from the lower unit, though the water pump and up into the upper unit. You access it by draining the oil from the drive and splitting the upper from lower units, like you do to change the raw water pump, which needs doing every few years.

In your case, it sounds like the u joints are knocking. Some knocking noise is normal and merc has a set of clips to minimize the noise. Other noise could signal a problem. Only inspection can tell if the noise you hear is normal or the indication of a potential problem. The drive should be removed from the gimbal housing and the u-joints inspected.

Best regards,
Frank C
 
you either have a u-joint going out or the gimbal bearing was replaced and not pressed in all the way.
you need to get this fixed before you run the boat again. if the u-joint fails, it can wipe out the whole bellhousing, rip your bellows and sink your boat.
don't "shadetree" this. have a mercruiser mechanic fix it correctly
you will probably need to change the bellows at the same time.
pay a merch tech to fix this correctly and it will be much cheaper in the long run.
 
Last edited:
Franks links to the book pages have disappeared from his post, if you have email notification set up they are in the email, at least they were in mine.
 
I do have email notification turned on but did not get the notification for that or most of the other posts.

Can you repost the links?

Thanks for all the information guys. I'll have to get with the Marina and have them take a look at it.

I'm hoping its not a dire situation.
 
Ok thanks I got them.

Thanks for all the info guys. I'll get with the marina and see what can be done to either quiet it down, or replace whats failing.


:thumbsup:
 
Ok, well I found this, https://appcenter.mercurymarine.com/litreq/orderForm.jsp?type=mc

If you get the engine serial number and the outdrive serial number, you can follow that link and order the shop manuals. I have found that even if you dont do your own work, it is handy to have the books so you can refrence your mechanic. Also, (and you shouldnt have to do this,,,) This way you can make sure your mech has the right manual.

Here is the "Contact Us" link for merc http://northamerica.mercurymarine.com/utility/contact/

The above links look great!!!! Looks like thats what you need. Pay the mechanic, a tow is usually in the $300 range!
 
Any good certified Merc technician can rebuild a drive to factory specs. A key factor is you need the proper factory tools which cost 2-3 grand. There are critical areas that must be set to spec, such as drive gear preload. Some of the processes are time consuming and tedious however, they must be done or the drive will fail.

Since Alpha Ones didn't enter production until 1983 you most likely have a Pre-Alpha, sometimes called a Merc #1. I have one on my boat. It is very similar to the Alpha One which improved upon the Merc #1 design.

Jack
 
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