Mercruiser alpha 1 gen 1 shifting issue, regarding shift cable barrel adjuster with locknut (not the larger brass one)

[Speeddemon007]

Hello, new here, and I've searched around, but can't find the answer to this specific question.

Had my new to me, 21' Thompson Cuddy, with 3.7L 180, and alpha 1 gen 1 out last weekend. Maiden voyage started out great.

Left the wives and kids on the dock, while my buddy and I went for the first ride on the lake, in case any issues came up.
Issue that arose, we fixed (somewhat) but I feel needs further adjusting.

Everything was working perfect, until it wasnt. The shift cable on top of the motor, has a brass barrel adjuster, but also has a locknut against another barrel adjuster. That locknut came loose, the barrel adjuster moved and I lost forward, in fact, all the way forward, was reverse, and reverse was reverse.

We adjusted it, so it engaged again, and had a great rest of the day. However, forward doesn't have a solid "click" into gear. Picture hitting the gas in a CVT transmission, you're just suddenly in first and moving, with no shift noise. Same with reverse.

Now, is there a proper measurement/setting for that rear barrel adjuster with the locknut.

Sorry for the long winded post, just figured I'd give some solid info on what happened.

Thank you for whatever help you can offer.
I'm not with the boat currently, but heading there next weekend, and hoping to get this properly adjusted.

 

[dubs283]

there are two shift cables in a mercruiser sterndrive system

one from the remote control at the helm to the shift plate on the engine and one from the shift plate to the bellhousing in the transom assy. known by the terms remote cable and lower shift cable

the item you have circled in the picture is the remote shift cable, in order to properly adjust it you first need to adjust the lower shift cable. to do so the drive must first be fully engaged in FWD gear. remove both cables from the shift plate assy. then with the lower cable cable end free from the shift plate assy, turn the brass trunion (barrel) on the threaded until a measurement of 6" between the center of the plastic end hole and center of the trunion is achieved. install the lower shift cable on the shift plate.

next place the remote control at the helm in the FWD detent position and adjust the trunion to fit onto the shift play assy with the lower cable still locked in the FWD position. before you install the shift assist mechanism shift the remote into NEU, REV and FWD while checking to ensure the prop is locked in gear and spins free in NEU.

with the remote in the NEU position you may then install the shift assist assy on the shift plate assy. if you are still having shifting issues try removing the shift assist assy and see if that helps, otherwise you may need to replace the lower shift cable, a common wear item in the shift system

 

[Speeddemon007]

Thank you. I'm pretty sure the lower shift cable has been replaced, which is why that locknut came loose, that or they adjusted everything, and didn't/forgot to tighten it up.
The item I circled is the brass piece with the locknut that sits up against it, this is what came loose.
However, I think I've figured out why I'm confused.
While thinking this piece is a separate unit, I guess it actually turns the threads Inside the larger barrel adjuster (trunion).
Therefore, if I just follow standard adjustment procedure, I should get everything back to functional (hopefully).
Locknut that came loose, is against the larger barrel in the second photo.

When you say "fully into forward gear" do you mean the shifter as far forward as it will go?

 

[Eric 3.7LX Alpha 1]

here's a video showing the procedure:

 

[Bt Doctur]

While thinking this piece is a separate unit, I guess it actually turns the threads Inside the larger barrel adjuster (trunion).

Incorrect. the threaded rod is threaded all the way in and the nut secures it, it does not secure the barrel adjuster

 

[Speeddemon007]

While thinking this piece is a separate unit, I guess it actually turns the threads Inside the larger barrel adjuster (trunion).

Incorrect. the threaded rod is threaded all the way in and the nut secures it, it does not secure the barrel adjuster

Okay, so if that's the case, and it unthreaded, if I thread it all the way back in, technically, I should be back to where I started. I'm wondering now, if the previous owner used that to adjust the shift cable, instead of doing it properly.
Now, that being asked, technically, if the cable was stretched, would this not be a way to take the length out of the stretched cable?

 

[Eric 3.7LX Alpha 1]

There is a limit to how much stretch a cable can have and still shift correctly.

 

[dubs283]

if the cable was stretched, would this not be a way to take the length out of the stretched cable?

no, the threaded tube you are referring to is independent from the inner cable which provides the shifting. even if the threaded tube moved from its normal, locked position from the outer sheath end the distance between the trunion and inner cable plastic end would remain the same. this is because the trunion would remain stationary in the shift plate and the plastic end would remain stationary as well. the only difference would be the length of the outer cable which may cause excess play or binding for the inner cable riding inside it

the inner cable is a plastic sheathed metal wound cable and not very prone to stretch. most issues are caused by the inner cable wearing the inside of the outer sheath causing slop or binding due to excessive debris from the worn outer cable

removed the lower cable and seat the threaded tube to the brass outer cable end. hold the brass end firmly with pliers and tighten the nut with a 7/16" wrench. then you can adjust the cables accordingly

 

[Speeddemon007]

no, the threaded tube you are referring to is independent from the inner cable which provides the shifting. even if the threaded tube moved from its normal, locked position from the outer sheath end the distance between the trunion and inner cable plastic end would remain the same. this is because the trunion would remain stationary in the shift plate and the plastic end would remain stationary as well. the only difference would be the length of the outer cable which may cause excess play or binding for the inner cable riding inside it

the inner cable is a plastic sheathed metal wound cable and not very prone to stretch. most issues are caused by the inner cable wearing the inside of the outer sheath causing slop or binding due to excessive debris from the worn outer cable

removed the lower cable and seat the threaded tube to the brass outer cable end. hold the brass end firmly with pliers and tighten the nut with a 7/16" wrench. then you can adjust the cables accordingly

At the end of the day, this is the exact answer I needed.
Thank you so much for the help, this will have me on my way to hopefully a solid season of fun and laughs.
Once everything is adjusted, I'll report back!

I will be removing the lower unit in the fall, and going through it, more than likely replacing that lower cable for peace of mind, the bellows (they're in good shape currently, but I don't know the age of them), the gimbal bearing, and inspecting the u-joints.