Mercruiser sterndrive help/parts?

[deserttoad]

Hi there,<br /><br /> I have a 1973 boat with a mercruiser sterndrive. The lower unit seized up last year, so I bought a used lower for it, only it doesn't<br />fit. I guess the last owner had it rebuilt and didn't tell me. The one I bought has a short eight spline shaft, but my upper gears take a 12<br />spline, longer shaft. I was hoping someone could tell me the best and least expensive fix for this problem. I was once told the best thing to do<br />would be to replace my upper pinion gears and buy an upper seal kit.<br /><br />Also, I don't know what drive I have and what I need (i.e. Alpha, Bravo,etc.) or what ratio or gear set I would need.<br /><br />Any info would be greatly appreciated.

 

[kdmiller8251]

Re: Mercruiser sterndrive help/parts?

What kind of boat??? Get some serial numbers off the drives to start... Without that info good luck..<br /><br />Tallman

 

[SS MAYFLOAT]

Re: Mercruiser sterndrive help/parts?

Gone thru your secenero several years back and boy what a headache. You need to mention what size motor you have. It makes a difference since there is a big difference in gear ratios between the 8 cylinder and 4 cylinder engines. Be patient there are members here that know exactly what you have and what you will need. I wish this post was around when I was having trouble with mine. But you are going to have to list what size engine you have. Good luck

 

[Trent]

Re: Mercruiser sterndrive help/parts?

1973 was a Mercrusier I drive. What horsepower you got?<br /><br /> Drive ID

 

[flashback]

Re: Mercruiser sterndrive help/parts?

give us some info, Trent knows what it takes

 

[deserttoad]

Re: Mercruiser sterndrive help/parts?

Wow! Just when I was beginning to think the landfill was the only place my old boat would ever sail again....<br /><br />Okay, I did leave a bit out. It's a 1973 Caravelle with a 4 cyl. 140 HP Merc. As for numbers, on the outside of the upper drive the number is 3387983.<br /><br />Also, I have all the repair manuals and one of them has the number 33531-80 written on it. It might be the number of the old Lower Unit, but you would all know better than me. .<br /><br />Thanks everyone!

 

[Trent]

Re: Mercruiser sterndrive help/parts?

Gear ratio is 1.98 for that setup.

 

[deserttoad]

Re: Mercruiser sterndrive help/parts?

Okay, so does that mean all I need to buy a set of used upper pinions gears in a 1:98 ratio and it will work?

 

[flashback]

Re: Mercruiser sterndrive help/parts?

This is out of my league, what splines are you refering to? the shaft that fits into the coupler or the other end. I am guessing at best but I think you may have a earlier model and trying to install a later model, I have read it won.t work but if the input shaft is the problem, you may be able to change just the shaft. Heck!! don't listen to me, I really don't know, <br /><br />Trent, you got any answers?

 

[RandyJ]

Re: Mercruiser sterndrive help/parts?

Toad. I recently went thru a similar episode. Well, not very similar. You probably have the same outdrive I have. I see some things where people are saying such and such lower units will interchange with i/o or outboards. Gears maybe but on the Merc I outdrives the lower unit definitely has a shorter driveshaft. Don't know if he has it for sale or not but this guy in north Alabama has a couple I'm sure he would part with one of them very reasonable if you want to contact him you can e-mail me @ freindsncompany@yahoo.com

 

[deserttoad]

Re: Mercruiser sterndrive help/parts?

ah! Right you are! The Lower unit I bought (for a 1973 outdrive) DOES have a shorter shaft. So what drive do I need? Since the one I ordered for the '73 didn't fit, I assume I need a newer model, but which one? The serial number listed on my upper should help with this I hope.<br /><br />And if so, looks like also have an older lower for sale...<br /><br />I'm just a farmer, not a sailor....

 

[mikeblare]

Re: Mercruiser sterndrive help/parts?

Hey toad going through the same sort of problem. with your serial number it sounds as if you need part number 45-41939a1 it has a preload pin on top of the shaft and I think it should be 13 splines not 12 but Ive been wrong before(you are talking about the vertical drive shaft right?) goto this url they have the best prices I have been able to find on anything their shafts have a one year warranty which isnt bad at all. Just copy and paste. http://www.amarket.com/im939.htm <br /><br />Good luck and happy rebuilding holler if you have anymore ?'s

 

[deserttoad]

Re: Mercruiser sterndrive help/parts?

Man I am confused. This shaft will replace the shaft from the lower unit into the upper pinion gears, right? So do I need to dismantle my lower unit to install it? I think I am trying to convert a 1973 old lower to a newer upper...<br /><br />I talked to one person that said nothing I could do but buy a different lower (said I needed a Mercruiser I drive) for $750, and nobody wants the old lowers like mine, so he'd give me $200 for it.<br /><br />This has been the most helpful sight so far, I feel the end of this problem is near...<br /><br />Thanks to all!

 

[mikeblare]

Re: Mercruiser sterndrive help/parts?

Yeah you need to dismantle the lower unit to replace. Its not that bad as long as you dont have to but new gears or bearings. First take off the prop and drain the gear oil throught the drain hole. Then if you dont have the proper spanner to remove the ring just behind the prop lay the case on its side on something to cushion it and using a dull cold chisel and hammer start on one side and start unscrewing the ring (there will be an arrow showing which way to take it off)work your way around the ring so you dont keep hitting on the same tab. Once you get that off youll need to pull the bearing carriage the best way is with long armed gear pullers, if you dont have those and the case doesnt look to corroded you might be able to wrap some good rope around the cross pieces and giving a good solid jerk get it loose. If that doesnt work you will need liberal amounts of heat and patience heat the case and keep working at it. once that isout youll have two ways to disassemble the rest if the shaft is in one piece grab hold of it with vise grips a couple of inches above the flat for the water pump and use an open end wrench on the nut at the bottom of the gear.once the nut is off you can pull the shaft and the gear will slip past the clutch dog aloowing you to pull the prop shaft and gear out. If the shaft is broke its a little trickier go buy a thin long flat bladed screwdriver a cheap one because you will be ruining it. file the flat into a narrow point heat the screwdriver and put a 3/4 inch bend down just shy of 90 degrees then at the very point bend in about an 1/8 of an inch to mak a little hook. In the middle of the clutch dog there is a little groove about 1/4 inch deep and thick there is a wire spring wrapped several times in this groove holding a pin in place feel around with your finger till you feel an end. thentry and hookit about an inch back pull it up over the dog grab it with a pair of needle nose pliers and unwind around the dog. Feel around the groove until you find the pin and use your tool to push it through. Once it drops pull out the prop shaft and dog then the gear and rest of the shft should be able to be pulled.

 

[deserttoad]

Re: Mercruiser sterndrive help/parts?

Thanks for all the help. The prop is already removed, so I guess I need to remove the horizontal shaft/bearings first then the vertical. I have a new water pump for it, so my question now is if there are any seals for the lower unit? I will be ordering the new shaft soon, and I know I need to get a an upper seal kit, is there anything else I need?<br /><br />Is it fairly simple to get this back together correctly, or should I take it to a boat shop? I am mainly worried about water leaking inside.<br /><br />Thanks again,<br /><br />Jim

 

[RandyJ]

Re: Mercruiser sterndrive help/parts?

Not really too bad to re-assemble, just lay out everything EXACTLY like you took it apart. Pay attention to how much play you have in propshaft & drive shaft before you start disassembly. Only really critical thing I found in my one and only lower unit rebuild was making sure the shims went back in just like they came out. If you have a drain plug with magnet be very careful not to break the magnet. Guy I bought my boat from thought the lower unit was locked up.... just the magnet off the drain plug was broken off and jammed in the gears. I got a very nice boat with a newly rebuilt Mercruiser 140 i/o for $1225.00 I fixed the lower unit and now I've got a $3500 boat...with new carpet & a good polishing it would sell for even more... all because of a bad assembly by an inexperienced mechanic. Also note, if you ever pull the engine make certain ALL motor mount nuts & bolts & washers & spacers go back EXACTLY as the came out or you will be replacing couplers frequently... and they ain't cheap.

 

[deserttoad]

Re: Mercruiser sterndrive help/parts?

Hi again,<br /><br /> Can't seem to get the bearing carrier out, hate to put too much heat to the aluminum, but it's soaking in penetrating oil for now. I'm not sure where it is hanging up but I'll try again tomorrow. Chipped a piece off it with my puller, so I'll have to replace it too (49.95, not too bad), hopefully I'll get it without breaking anything else.<br /><br />Thanks again,<br /><br />Jim

 

[deserttoad]

Re: Mercruiser sterndrive help/parts?

Hooray! I have successfully removed all parts. New ones are on the way. I had to weld up my own puller, but I finally got the guts out.<br /><br />Just hope I can get it all back together correctly.<br /><br />Jim

 

[Markboat]

Re: Mercruiser sterndrive help/parts?

Here’s what I know:<br />Boat: Glastron Sierra, 19 foot Cuddy<br /><br />Engine:<br />5.0 Liter, Chevy V-8 <br />Serial #: 06674553<br /><br />Outdrive:<br />Mercruiser Alpha One, (R.H. ROTATION) <br />The serial number on the sterndrive itself is different from the one the inside of the boat cover says. The sterndrive label says: 0C815142, the Mercruiser web site doesn’t recognize the number.<br />The sterndrive serial number on the inside of the motor cover is: <br />Serial Number: 0C629497 <br />Model Number: 5010165BS<br /><br />Prop was:<br />Black Max Stainless<br />PROP NO RPT NO. RAKE<br />48-16316-19 19RBM 20 DEG<br />This was a 3-Blade Prop<br /><br />Here my problem:<br /> At low speed while turning slightly to pick me up after a waterskiing fall, my brother hit the top of a large boulder. The prop bent up on the blade tips, and the Prop Shaft no longer turns when the boat is put in gear. I know, really bad right? But I drained the Outdrive lubricant I found little or no metal fleck. We also never heard any gear grinding noise or vibration. When we run the engine in gear, there is no vibration. When I turn the now free turning prop shaft, there is no resistance of any kind. I tried to pull the thing open and failed. It loosened but would not pull off. I also did not have and could not find to buy the “Outside Star” style socket required to remove the plate just on top of the upper gears.<br /> So far I ordered a manual called, “Clymer Marine Repair Manual Mercruiser Stern Drives-Alpha One, Bravo One, Bravo Two & Bravo Three 1986-1994”<br />Is that the one I want? Or do I just want the Merc service manual and parts catalog?<br /><br />Here’s what I need to know:<br />1- Is a gear almost certainly stripped?<br />2- Is it likely that something else gave way?<br />3- And of so, what?<br />4- What is my correct Gear Ratio?<br />5- Where the heck do I get a star socket?<br />6- What the heck did I most likely miss trying to get the Outdrive off?<br /><br />7- I was gonna replace the prop by getting two composite props, from Comprop, via Overtons.com, they are both 4-Blade, one is 13.7 dia. x 18 pitch, the other is 13.6 dia. x 20 pitch. Any comments or suggestions on using either of these?<br /><br />8- Here’ what I want to know:<br />9- What’s the horsepower of my engine?<br />10- What’s the cubic inches of my engine? <br />11- How can I increase the horsepower?<br />12- Can I ever put in a larger engine?<br />12- What size engines are likely to fit?<br />12- Can anyone recommend an online dealer that might have everything I am seeing at MercruiserExpress.com?<br /><br />Loads of thanks in advance for anyone with helpful info,<br /><br />Markboat

 

[Markboat]

Re: Mercruiser sterndrive help/parts?

O yeah, the Glastron Sierra is a 1990.