Shift cable

CNYcorey

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Sep 19, 2024
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Hey everyone, this is my first post here and I'm happy to be aboard. Sorry in advance for the lengthy post. I have a 1973 StarCraft SS I/O. I've installed a new shift cable but the adjustment is not going well. I really should have a manual but I've been getting my info online, so it's been a bit difficult finding the pertinent info for my particular setup. Anyway, I've installed the new style lower shift cable. It had to be tapped out and fastens through the back side instead of the front side like the existing one. I'm wondering if I got any important details wrong (because I know there's not much forgiveness and things seem to need to be exact.) I left about 3 threads showing on the brass fitting going into the hole on the bell housing that I tapped. I tightened the little threaded plug that traps the cable in and backed it off about 1/8" and wrapped the wire back on so it can't move. I'm not sure if that was proper because I've seen conflicting info. Some saying to leave 1-3 threads showing on the brass fitting and some saying to tighten the threaded plug and back it off only a half turn.
After thinking I had installed the cable properly, I moved on to the adjustment and I can't seem to get it right. Adjusting the (lower SC) barrel to 6", 4 turns away from the plastic end, I'm still getting clacking when the prop is spun. I'll get full engagement at the 10 o'clock forward position but that's about the best results I can seem to get. So that leads me to believe I need to pull the out drive back off and adjust something there. Another thing I know I did wrong, was that I bought and aftermarket shift cable that's supposed to work for my application but it was tight in the stainless tube at the end and was rubbing and binding a bit. I filed that down and got it to run smoothly and effortlessly. In hindsight, I wish I got the OEM cable but I was hoping to work with what I've got now. Any help/insight is greatly appreciated, thank you!

PS I'm a carpenter by trade and not much of a mechanic, but my whole life, I've done my own repairs out of necessity. So I'm mildly capable, doing repairs in my driveway that are not extremely difficult.
 
Joined
Sep 14, 2024
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I am not an expert, but I have done this exact same job once, last June, and everything turned out perfectly. I have a 1976 120 with an MC-1 drive. Did the tap thread-chasing thing.

There are a couple of things I did differently than you, no doubt because we followed different online "how-to" write ups. I only left one thread on the big brass nut showing (actually, I screwed it in until it bottomed out, then reversed it out one turn). Another thing is I tightened the set screw on to the end of the cable until it just touched, so it was free to rotate but no fore and aft movement was possible. Also, I used a genuine Mercury cable and other parts that came with it in a kit.

As to your perceived problem, are you saying the prop is clacking when the drive is supposed to be in neutral? Full forward at 10 o'clock sounds right. I'm just trying to clarify what you think the problem is.
 

CNYcorey

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Sep 19, 2024
Messages
7
I am not an expert, but I have done this exact same job once, last June, and everything turned out perfectly. I have a 1976 120 with an MC-1 drive. Did the tap thread-chasing thing.

There are a couple of things I did differently than you, no doubt because we followed different online "how-to" write ups. I only left one thread on the big brass nut showing (actually, I screwed it in until it bottomed out, then reversed it out one turn). Another thing is I tightened the set screw on to the end of the cable until it just touched, so it was free to rotate but no fore and aft movement was possible. Also, I used a genuine Mercury cable and other parts that came with it in a kit.

As to your perceived problem, are you saying the prop is clacking when the drive is supposed to be in neutral? Full forward at 10 o'clock sounds right. I'm just trying to clarify what you think the problem is.
Thank you for your response!
Yes, exactly. In the first couple steps of the adjustment process, when in neutral, there's some clacking when the prop is turned by hand. So from the very beginning, that tells me something isn't right. I think I need to take the out drive back off set it up as you stated, (one thread showing on brass fitting, almost tight plug) then start my adjustment.process. I think my problem is that there's so many different outdrivies with different processes for each one. Now I'm just hoping the same process applies with your '76; and my '73 and that the non-OEM cable is Ok.

I'm so close I can smell it so I have a feeling this is going to work. I'll report back with results. Thanks again!
 
Joined
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Thank you for your response!
Yes, exactly. In the first couple steps of the adjustment process, when in neutral, there's some clacking when the prop is turned by hand. So from the very beginning, that tells me something isn't right. I think I need to take the out drive back off set it up as you stated, (one thread showing on brass fitting, almost tight plug) then start my adjustment.process. I think my problem is that there's so many different outdrivies with different processes for each one. Now I'm just hoping the same process applies with your '76; and my '73 and that the non-OEM cable is Ok.

I'm so close I can smell it so I have a feeling this is going to work. I'll report back with results. Thanks again!
Do you get reverse at about 2 o'clock? Does the clacking in neutral ever go away on the way to reverse? Is it possible you might get it right just by rotating the barrel a little more in one direction or the other away from the 6 inch dimension? Did you verify by serial number that your cable was the right one for your drive?
 

Pmt133

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Jan 6, 2022
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571
Pre 1976 drives have a different adjustment for the cable if memory serves... 5-7/8" maybe?
 

CNYcorey

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Sep 19, 2024
Messages
7
Do you get reverse at about 2 o'clock? Does the clacking in neutral ever go away on the way to reverse? Is it possible you might get it right just by rotating the barrel a little more in one direction or the other away from the 6 inch dimension? Did you verify by serial number that your cable was the right one for your drive?
No, I couldn't get reverse. I'm not sure if it goes away on the way to reverse. I don't think so. I could check but it would be a little while until I can get some help. I've tried moving the barrel a bit in either direction. I didn't verify by serial number because I can't seem to find the info anywhere. I really need a manual because I don't even know what I'm calling my setup/out drive. The cable I got is for alpha 1 gen 1/2. I was told it would work but it would be nice to know for sure. The serial number is 3584610.
 

Scott06

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Apr 20, 2014
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No, I couldn't get reverse. I'm not sure if it goes away on the way to reverse. I don't think so. I could check but it would be a little while until I can get some help. I've tried moving the barrel a bit in either direction. I didn't verify by serial number because I can't seem to find the info anywhere. I really need a manual because I don't even know what I'm calling my setup/out drive. The cable I got is for alpha 1 gen 1/2. I was told it would work but it would be nice to know for sure. The serial number is 3584610.
if you are having trouble getting reverse did you adjust the slotted lever I think around 2:50 in this video?

\

if you have a factory manual it will be outlined in there.
 

CNYcorey

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Sep 19, 2024
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Yes. I've watched this video and the slot didn't seem to help. My setup is also slightly different than this guy's boat. Instead of the cables being parallel to the boat, they are perpendicular, mounted on the transom, above the engine.
 
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Sep 14, 2024
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I was told it would work but it would be nice to know for sure. The serial number is 3584610.
I have a dealer parts manual from September 1976. It lists as the original part number for your cable as B-49518A1. That number was superseded by part number 73723A01, which is what they sell today to fit all MC-1 through Alpha Gen 2 drives. So your part should be OK. I believe you have an MC-1 drive.

The order of things, in my opinion, should be this. First remove the drive and make sure you can still get forward, neutral and reverse by hand shifting the top of the lower shift shaft. If yes, you know the problem is not in the drive. Then look for some reason why your cable, upper shift shaft, remote control, etc. are not transmitting the same motion as your hand shifting. I don't think the minor adjustments to the brass nut and set screw are going to solve the problem. There is something grossly wrong with your shift system.
 

CNYcorey

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Sep 19, 2024
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Ok, awesome! Thank you for this valuable info! I'll post updates as I go. It's raining today unfortunately.
 

CNYcorey

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Sep 19, 2024
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In the meantime, here's a little background info: I had some shifting problems for a while this summer where I'd lose forward or reverse here and there. In hindsight, the throttle lever wasn't very smooth. I would adjust the cables and be ok for a little bit but never perfect. I would continue to have problems. At one point, my prop hit some rocks on the St Lawrence River (it's a bit treacherous.) A month or so later, I lost all shifting capabilities and had to get towed in. That's when I found, at the outdrivie, the cable core was severed and the cable sleeve was also all shot, and torn up. All the damage was on the outdrivie before the transom about 6" past where it fastens to the bell housing.
Another thing I noticed when doing the shift cable is that when I pulled the outdrivie, there was milky brown oil up in the bellows where the U-joints and drive shaft go in. I'm wondering if that would be due to the 2 O-rings on the drive shaft needing to be replaced.
Also, when I opened the oil vent at the top of the outdrivie, a little bit of fluid came out. The color looked to be a nice blue color like when it went in but glittery with specs of metal. I didn't change the outdrivie gear oil this year though so it's the same oil I put in last year. I have yet to pull the bottom screw and see how much metal is there but I'll be doing that shortly.
 
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Sep 14, 2024
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I had a dodgy shift cable too. It was drawn tight across an engine bell housing edge, the cable had finally hard-kinked there, and the sheath was about half cut through. The inner core was being forced back and forth over that sharp edge. Movement required so much force it also wrecked my remote control. I am assuming this was the main reason this was a free boat. (I was looking for an interesting project like this.) Suggest you verify operation of your remote control as well.

Oil in the bellows is bad news. Does it smell like gear oil or engine oil? I had about a half cup of gear oil in my bellows, and resealed the drive shaft yoke to fix that.
 

CNYcorey

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Sep 19, 2024
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Yeah, it looked like milky engine oil. Not much of it. There's 2 ancient 0-rings on the drive shaft and I've had it in and out a few times so I'm going to start there.
But, SUCCESS!!! I pulled the outdrivie back off and poked around a bit and came to realize my non-OEM cable was a real turd and the source of my headaches. The slide mechanism was hitting the step from the plastic tube to the brass fitting. I had to file down the sharp edges on both and cut a Bic pen in half and use it as a sleeve inside the slide and over the fitting. (It was loose as a goose for whatever reason). It's much smoother now and I have gears. The cable is super cheesy compared to the old one that came off so that's a regret, but we'll see how long it lasts.
 

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Scott06

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Yeah, it looked like milky engine oil. Not much of it. There's 2 ancient 0-rings on the drive shaft and I've had it in and out a few times so I'm going to start there.
But, SUCCESS!!! I pulled the outdrivie back off and poked around a bit and came to realize my non-OEM cable was a real turd and the source of my headaches. The slide mechanism was hitting the step from the plastic tube to the brass fitting. I had to file down the sharp edges on both and cut a Bic pen in half and use it as a sleeve inside the slide and over the fitting. (It was loose as a goose for whatever reason). It's much smoother now and I have gears. The cable is super cheesy compared to the old one that came off so that's a regret, but we'll see how long it lasts.
The o rings on the driveshaft are to keep it tight in the gimbal bearing, nothing to do with water. Make sure the big quad ring is glued in the bellhousing.
if its gear lube mixed with water it is from inout shaft seal On drive, if grease it’s from the gimbal bearing. Either way the water should not be there
 
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Yeah, it looked like milky engine oil. Not much of it. There's 2 ancient 0-rings on the drive shaft and I've had it in and out a few times so I'm going to start there.
But, SUCCESS!!! I pulled the outdrivie back off and poked around a bit and came to realize my non-OEM cable was a real turd and the source of my headaches. The slide mechanism was hitting the step from the plastic tube to the brass fitting. I had to file down the sharp edges on both and cut a Bic pen in half and use it as a sleeve inside the slide and over the fitting. (It was loose as a goose for whatever reason). It's much smoother now and I have gears. The cable is super cheesy compared to the old one that came off so that's a regret, but we'll see how long it lasts.
Great recovery, with that bit of a Bic pen. Respect.
 

Scott06

Admiral
Joined
Apr 20, 2014
Messages
6,428
Yeah, it looked like milky engine oil. Not much of it. There's 2 ancient 0-rings on the drive shaft and I've had it in and out a few times so I'm going to start there.
But, SUCCESS!!! I pulled the outdrivie back off and poked around a bit and came to realize my non-OEM cable was a real turd and the source of my headaches. The slide mechanism was hitting the step from the plastic tube to the brass fitting. I had to file down the sharp edges on both and cut a Bic pen in half and use it as a sleeve inside the slide and over the fitting. (It was loose as a goose for whatever reason). It's much smoother now and I have gears. The cable is super cheesy compared to the old one that came off so that's a regret, but we'll see how long it lasts.
We have all learned the hard way on aftermarket parts not worth the aggravation. My shift cable is 20 hrs old original bellows lasted 18 years and we’re still in decent shape… why bother messing around

One of the few things I do buy aftermarket is u joints. The oem perma lube merc ones don’t last that long. I have the GKN ones on my gen 2 the casting number in it crosses to the same GKN U joint for RWD Volvos … you can get a good quality spicer for a qtr the cost
 
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