unGodly grinding noise coming from 165 outdrive

[seanable]

Hello Folks.
OK, so, I learned how to fiberglass, and glassed the deck on my '71 Thunderbird cuddy. Hand buffed 15 years worth of oxidation off of the hull, swapped out the lower outdrive, bought a new prop, buttoned up the wiring, new gauges where needed, new Walmart seats, new carpet, etc. etc. basically hemorrhaging money..take it out to lake Oroville last night...the 165 L-6 runs beautifully (after a carb. rebuild, new wires, oil change...) BUT...the outdrive makes a horrid grinding noise. I have run cars with wore out transmissions, and this noise is similar but louder and scarier First question...What would be making that noise? It is obviously a bearing. It makes the noise in gear or not, and is more pronounced while in gear. i'd just as soon fix the 165 outdrive...but wouldn't mind taking this as an opportunity to upgrade...which brings me to my next question...
I acquired, sometime back, a 1987 Mercruiser 4.3 ltr. V-6. I sold the V-6, which was like new, leaving me with the outdrive, which sits in my yard. I would like to take this outdrive from the 1987 (which i believe to be an alpha one) and hang it where the '71 model 165 outdrive is. will it bolt up? are there any internals that are interchangeable? (hoping that I could fix the racket for no money, only my time and such. I also have the option of an older jet pump.....but i don't have it here and no information on it yet.
the old cuddy is epic fun. my wife and i had a blast. i am looking forward to taking the family out on it for some good memory making times. This forum has been key to me successfully making a lot of the repairs on this old cathedral hull. THANK YOU. and when i know what i am talking about enough to give sound advise, i will do that here.

 

[stonyloam]

Re: unGodly grinding noise coming from 165 outdrive

Not sure if it will bolt up, but first things first. Pull the outdrive and check the gimbal bearing and U-joint (more likely to be bearing). Could be as simple as a new gimbal bearing is needed.

 

[seanable]

Re: unGodly grinding noise coming from 165 outdrive

That's what I'm gathering by reading other threads on this site. I will be studying the factory manual, a beautiful thing to have access to here (many thanks to the late Don S). I am clearing a spot to perform this operation and will follow up after i get 'er tore down.

 

[achris]

Re: unGodly grinding noise coming from 165 outdrive

Yes it will bolt up, but you'll need to change the yoke shaft first. The internals are not interchangeable.

The noise in the current drive could be bearings or a cracked gear. Either way, it will be cheaper to put a new SEI drive on. You can't buy the special tools required to do the job for the cost of a new drive...

Chris.......

 

[seanable]

Re: unGodly grinding noise coming from 165 outdrive

OK, achris, that is great news. I'm going to go dig the alpha one unit out after I get done with this. How about gear ratio? the Alpha one, as i likely stated before was behind a 4.3 V-6....pretty close to a 4.1 L-6, except, i imagine there would be torque variances between the two. close displacement, similar horse power...gearing should be close. should be..
Is the alpha one an improvement over the mercruiser 1. I truly appreciate your time taken to answer my questions.

 

[seanable]

Re: unGodly grinding noise coming from 165 outdrive

OK...done some research. the alpha one outdrive has a 1.84 ratio, tooth count; 17-19. the 4.3 ltr. = 262 c.i.
My 165 L-6 is only shown to be 3.7 ltrs. (224c.i.) the ratio behind it is...1.65, tooth count; 24-24, a bit lower geared than the alpha one. I've run motorcycles all my life, and played with gearing, both in the primary, and final drives. i have swapped rearends in old pick ups to give them the cruising speed of a sedan, are boats at all like this? There are a LOT of mitigating factors at work here. I am stymied. please help.
I'm gonna create a fresh thread with this puzzle. it is one for the boat wizards for sure.

 

[seanable]

Can I successfully use a higher geared outdrive? 1.84 > 1.65 ?

Can I successfully use a higher geared outdrive? 1.84 > 1.65 ?

The outdrive in my Thunderbird cuddy makes a noise that makes me hurt physically while running it. It is a 1971 Mercruiser 165 L-6 currently. I can dig into the 165 outdrive, maybe find what is dying in there, and attempt a sound repair not having the alignment tool, etc. to do it right...OR...I have a complete Alpha One unit that was behind a 1989 4.3 ltr. V-6. I have just learned that the Alpha One outdrive has a 1.84 gear ratio, and a tooth count of 17-19. This is opposed to the 165 outdrive having a 1.65 ratio and a 24-24 tooth count.
I have played with the gearing on my motorcycle..primary drive and final drive..still have yet to find my optimum combination..but i get the concept, somewhat. Boats have many variances though...i am trying to wrap my brain around it all, but not quite there yet. The Thunderbird is 18 ft. will be used primarily for cruising, WOT of 4900 RPM.
I was informed that the newer unit will bolt up but i would need to change the yoke. Wouldn't i be able to recover some of the gearing change back by varying the prop? :facepalm::laugh::mad-new::laugh:
I thank you in advance for your thoughts on this.

 

[FreeBeeTony]

Re: Can I successfully use a higher geared outdrive? 1.84 > 1.65 ?

Re: Can I successfully use a higher geared outdrive? 1.84 > 1.65 ?

FYI...........the WOT of the IL6 is more like 3900-4200RPM's.......
What pitch prop are you currently using?

 

[seanable]

Re: unGodly grinding noise coming from 165 outdrive

When I put 4900, i meant to go glance at my tach, it was like 3900 RPM not more than though. The prop has a 19 pitch. the only thing stamped on it is 19 A4 .

 

[achris]

Re: unGodly grinding noise coming from 165 outdrive

The original ratio on the L-6 was 1.65:1. If you are currently running a 19" and only pulling 3900, with the 1,84 and the same prop you should get around 4350. If you are not in the habit of running 'balls to the wall' all the time, that should be perfect... If you like your WOT, then get a 21" prop (should pull it down to about 4000).....

Chris.........
(I run a prop that would allow over 5100 on my engine... Love it!)

 

[seanable]

Re: unGodly grinding noise coming from 165 outdrive

well, i'm *** deep in outdrive. the gimbal bearing is hammered kitty poo, and sure was telling me all about it. i got the circlip out, and went to harbor freight for their "rear wheel bearing puller", got online and found a set of bellows, and a gimbal bearing for $102 shipped.
i always like this part of a repair, because i have located the problem, have the new parts in hand...still a few unanswered hurdles..such as how to avoid buying an alignment tool. oh AND getting the damn gimbal bearing out. i tried a slide hammer (btw, the smallest puller in the set works, in theory so far). i guess i'm pulling the gimbal housing next...i'm off to the wonderful, God i dont know what i'd do without it, manual section here....any body have any thoughts?
Oh, the bearing was cheap, because it is cheap. I used to think,"if we get in a war with china, they'd kick our asses"...nope, their machinery is epic junk. junk, junk, junk. If the Third Reich taught us nothing else, it was that well built, well designed machinery will win a war (however, a madman, and a circle of creeps and freaks will lose even faster). guess where my new bearing is from? no...not Germany. C H I N A. wonder if it'll last a year?

 

[GA_Boater]

Re: unGodly grinding noise coming from 165 outdrive

If you don't use the alignment bar, there is a good chance it won't be long before you are doing the same work all over again, along with a new coupler.

 

[Sangster21]

Re: unGodly grinding noise coming from 165 outdrive

I really don't think you want to re install the outdrive without first checking with an alignment bar. I think they can be had pretty reasonably from e bay, I found the dimensions here on iboats and machined my own. As far as pulling the gimbal bearing if you don't have luck with the slide hammer, use a piece of threaded rod and a plate that goes against the bell housing and pull it out that way. I am not sure if yours has it or not, but did you check for and remove the snap ring that retains the gimbal bearing?
Alan

 

[CharlieB]

Re: unGodly grinding noise coming from 165 outdrive

Just for the experience, change oil in your old drive, looking for any metal. You can pull the top off the upper gearcase and inspect the upper gearset, but you will need to replace the o-ring seal under the cap/cover.

Hopefully the O/D is fine and the gimbal bearing is the only noise-maker.

Have you checked iBoats prive on a gimbal bearing? I don't think it is chinese!

 

[998cc]

Re: unGodly grinding noise coming from 165 outdrive

still a few unanswered hurdles..such as how to avoid buying an alignment tool. oh AND getting the damn gimbal bearing out. i tried a slide hammer (btw, the smallest puller in the set works, in theory so far).

You can borrow mine. One of my kids goes to Chico State and makes trips back and forth to Shingle Springs.

998cc
1972 Gulfstream, Mercruiser 165 L6

 

[Bondo]

Re: unGodly grinding noise coming from 165 outdrive

oh AND getting the damn gimbal bearing out. i tried a slide hammer (btw, the smallest puller in the set works, in theory so far). i guess i'm pulling the gimbal housing next...

Ayuh,..... Welcome Aboard,..... Don't pull the Housin', use it as a perch for the puller yer gonna build,...

Ya need a length of threaded rod, 3/4" or so, 'n some nuts, 'n of course various sized washers,...

Put 1 end of the rod through the bearin', 'n use washers, 'n a nut on the inside of the hull,...

Then bridge the housin', 'n use more washers, 'n another nut,...

turnin' the outer nut will pull out the bearin',....

'n,.... ya Gotta have an Alignment bar,... No way 'round it,...

 

[GA_Boater]

Re: unGodly grinding noise coming from 165 outdrive

You can borrow mine. One of my kids goes to Chico State and makes trips back and forth to Shingle Springs.

998cc
1972 Gulfstream, Mercruiser 165 L6

And that's an offer you can't pass up, seanable. Only cost would be a six pack or two of 998cc's favorite beverage. :joyous: