Pre Alpha Shifting Problems

[Scott in MN]

'80 pre alpha lower unit on a Mercruiser 228 on a Searay
Shifting has been vauge. Came into dock the boat and had to put it in reverse and then couldn't get it out of reverse. Looked at the shift plate and the black plastic cable end guide on the lower unit shift cable was bending, preventing the cable to be pushed in. I could reach in and straighten it, upon which it would shift into forward. I figured that the previous owner had been shifting it without the engine running, causing it to bend.

I thought this would be an easy fix, just install a new cable end guide and adjust everything per the manuals. I installed the new guide on the cable and while off the shift plate had no problem pushing the cable in to engage forward, however when I pull on the cable it will not go into reverse. Yes, I have a helper turning the prop when trying to shift. Feels like it is close. It catches a little but not to the point where it is in gear. Seems like the cable needs to slide a little further.

What's going on? Reverse was working. Maybe just barely? I didn't really mess with anything to change anything. Previous owner had his boat mechanic install a new lower unit shift cable last spring and its operation is smooth. Is there something on the other end of the cable prventing it from sliding a little further or engaging reverse.

 

[Bondo]

Re: Pre Alpha Shifting Problems

You only have to post your Question Once,.......
If you're using your Back Button,..... Be Sure to Refresh the page to See your post........


As for your Problem,.......

I'd think that you Probably need to Replace the Complete Cable...........
It's Probably Stretched from the abuse of the earlier problem........

 

[Scott in MN]

Re: Pre Alpha Shifting Problems

Don't know what I did to post twice. Unintentional. I requested the duplicate to be removed.

Even if the cable was stretched, if I have the engine end of the cable removed from the shift plate and am pulling on it, shouldn't it move the shift slide in the upper lower unit as far as it can go? Should not make any difference if the cable is stretched?

 

[Haut Medoc]

Re: Pre Alpha Shifting Problems

Shift spool/crank wear or excessive play?......
With the drive off of the boat, will the drive itself go into reverse?
Is the shift fork bottoming into the bell housing & preventing that little extra you need to engage reverse?.......
I would do these tests/observations.......
There are tests outlined in manual #6 on how to check......
http://www.boatfix.com/merc/Servmanl/6/6covr3.pdf
Section 1C, page 42 or so......​

 

[Scott in MN]

Re: Pre Alpha Shifting Problems

OK,
I removed the drive last night. It shifts fine into reverse when I turn the shift shaft coupler and turn the prop.

Also did the other tests. I got 11/16" of play in the cable instead of the max. recommended of 9/16" (p. 1C-39). I then hooked up the degree gage and pointer (1C-41) and measured 13 degrees of movement. According to the manual this implies that the problem is with the gear case shift spool assembly.

I don't want to hear that I need to dig into the gear housing. It just seems that if I could get another 1/8" movement of the shift slide it would take care of the problem.

I should also say that the lower shift cable is very smooth, still feels like a new cable.

 

[Haut Medoc]

Re: Pre Alpha Shifting Problems

This was replaced when?.......
Why is it all crusty?......
If your cable is sticking or bottoming on the last 1/8", you won't get the rotation on the shift crank that you need.....
If you did not replace the entire cable assembly, now is the time to do so......
How much play is in the end of the shift slide?......​

 

[Scott in MN]

Re: Pre Alpha Shifting Problems

I was told the cable was replaced spring of '06. I assumed they replaced the whole assembly.

Crusty? Ha, I thought all old drives looked like this. I suspect some water leakage was occuring. Is it a definete no no to use even a non silicon gasket sealer when reassembling?

Cable is not sticking, but is bottoming out on the brass cable guide shown in the picture.

Play in the end of the shift slide? Not sure what play you want me to measure. No play in the shift slide on the cable, there is a positive conection at the set screw end of the slide, right? While in forward I measured the 11/16" of play in the whole system as measured following the proceedure on page 1C-39.

 

[Haut Medoc]

Re: Pre Alpha Shifting Problems

I was told the cable was replaced spring of '06. I assumed they replaced the whole assembly.

Crusty? Ha, I thought all old drives looked like this. I suspect some water leakage was occuring. Is it a definete no no to use even a non silicon gasket sealer when reassembling?

Cable is not sticking, but is bottoming out on the brass cable guide shown in the picture.
All I'm sayin' here is that if the cable bottoms out before it can turn the shift shaft enough to engage reverse, you are SOL.....​

Play in the end of the shift slide? Not sure what play you want me to measure. No play in the shift slide on the cable, there is a positive conection at the set screw end of the slide, right?

Yes the cable end to set screw was what I was referring to.....​

While in forward I measured the 11/16" of play in the whole system as measured following the proceedure on page 1C-39.

For the $45 bucks or so, I would throw a new cable at it & see what happens......
There is one more thing.....
If the upper shift shaft lever is contacting the bell housing preventing enough travel to engage reverse, you might try grinding a bit off of it to get that little extra......
If that makes it work, I'd start shopping for a new lower.....
That would mean that the shift crank in the gearcase is worn & will need to be replaced.....
The fix I suggest might buy you some time, but how much is anyone's guess.......​

 

[Haut Medoc]

Re: Pre Alpha Shifting Problems

Looked at your picture again, the shift slide should be able to go all the way in so that the shift crank can contact the bell housing.....:redface:
Something is preventing that.....
I would definately put a new cable assembly on, I don't care how smooth you think it feels, it should be capable of more travel than that if disconnected from the shift plate....​

 

[Scott in MN]

Re: Pre Alpha Shifting Problems

Shift crank being the arm on the top of the upper shift shaft with the roller on its end that sets into the shift slide, right?

What's your word on using a little non silicone gasket sealer when installing the drive?

 

[Haut Medoc]

Re: Pre Alpha Shifting Problems

Shift crank being the arm on the top of the upper shift shaft with the roller on its end that sets into the shift slide, right?
YES.......

What's your word on using a little non silicone gasket sealer when installing the drive?

Ya don't need it.......
It's the large o ring that keeps the water out of the ujoint bellows......​

 

[Scott in MN]

Re: Pre Alpha Shifting Problems

Thank you for your assistance.

 

[Don S]

Re: Pre Alpha Shifting Problems

You shouldn't need any sillycone to seal that. A new gasket and orings EVERY time the drive comes off is a must.
You also should change the bellows. Looks like a water and oil mixture in there. Probably water in the drive also.
You also have the OLD style shift cable, who knows if it was installed correctly.
Here is a Merc Service bulletin regarding shift problems on the one drives. That manual is for Alphas and the wrong one.
You should get manual #4 for your drive.

Service Bulletin