No Neutral, intermittently

[whans]

This weekend on running the engine for the first time this year I experienced a problem I've never had before: The engine was warmed up and I had had it idling in forward for a while. I opened the throttle some more and after running for a few minutes the engine all of a sudden shut down, abruptly. It started again right away but it seemed to have no neutral zone on the shifter-- it was either in reverse or forward and I couldn't find the middle. In forward it wouldn't run hardly at all but in reverse it was fine. It was almost as if reverse was kicking in on top of the forward, binding it up and stalling it.

Inexplicably, the problem disappeared. I wasn't able to completely reliably reproduce it, but it did happen again a couple of times. It seemed related to running the engine in forward for a period under a substantial load. Again, after shutdown and restart it was almost impossible to find the position where it was in neutral-- the shaft either spun in one direction or the other and it seemed the two directions were almost fighting each other. I verified with the shift lever directly so I'm pretty sure it's not the linkage, which is phenomenally simple anyway.

I've never had any gear issues at all so I'm posting here on Monday morning before having looked inside it at all. Thanks for any suggestions.


Whit

[Baltimore Sailor]

I think I'd take the cover off the tranny and have a look inside. Make sure nothing's come loose, fallen off, etc. Take pictures and post.

I don't have much of a neutral zone either, but that's just a reversing gear adjustment issue. When you weren't getting good forward could you still feel the detent when you shifted?

[whans]

When you weren't getting good forward could you still feel the detent when you shifted?

Yes, the detent felt just fine.

Thanks. I figured I'd probably have to open it up, but I'd like to see if I can get an ideas here first.

[Baltimore Sailor]

Theoretically, I gues you could have the reverse binding the forward (or vice-versa). Reverse "gear" is just a braking band that grabs the the driveshaft when you push the shifter into reverse. If it were set too tightly it would grab all the time, even when in forward, which would no doubt cause problems.

I doubt that's what's happening with you, but getting the cover off is easy if you have access, and it's always good to see what stuff looks like in an engine.

[whans]

Well, I opened it up and things looked fine, as far as I could tell. I adjusted the reverse gear and that seems to have fixed the problem. I'm wondering a couple of things:

-- Does the reverse just wander out of adjustment? I've never had a problem with it in years of light duty use.... and now all of a sudden it acted up. There doesn't seem to be any locking mechanism on the reverse adjustment screw... or did I miss it?

-- What would account for the fact that the neutral zone seemed to disappear only after running under substantial load for maybe 10 minutes? I had idled in forward for a much longer time with no problem, but then it happened after period of operation under higher load.

[hanleyclifford]

There should be a spring on that adjusting nut.

[HalfHourEarly]

Think I just posted this post in the wrong thread so here it is again

I just got my Viking 33 back in the water and my A4 has a constant wine similar to the reversing gear engagement. when I disengage the shaft, the wining stops drive coupling spins and noise is gone. I replaced my cutlass bearing and stuffing box packing so the shaft does not spin very freely yet (but spins by hand with just a little effort). I have tried backing off the brake adjustment nut a couple of steps but it seems to have no effect. here's some background:

-pulled the engine this spring.
-removed the drive coupling and changed the shaft seal.
-replaced oil with penzoil high mileage 10W30 + Lucas Oil Treatment.

Funny thing is, up until this work was done, the engine would actually go into neutral and not spin (not much neutral but it was possible to hit it).

Is it possible that something is not disengaging in the Reversing Gear?

Really need help, thanks.

[roadnsky]

Are you saying that you have NO forward?
Or just no Neutral?

In theory you're supposed to set the Forward for good detent and then adjust Reverse.
When you say you've "tried backing off the brake adjustment nut a couple of steps"...
Can you be a little more specific as to what you've done?

[HalfHourEarly]

roadnsky

I have a good detent in the forward and when that happens the "wine" stops immediately. But, as soon as I pull out of forward it appears that I am going right into reverse (but not fully engaged). What I did with the brake is turn the reversing gear adjusting nut about a quarter - half turn. It sounds like simply backing off the tension on reverse should do the trick and maybe it would if i turned it more. However, it doesn't make sense why this would happen all of a sudden.

[Al Schober]

Hey Half...
The fwd and reverse adjustments are completely separate. Fwd has it's own detent, and when you're in it, fwd shouldn't slip - if it does, you need to snug up the fwd adjustment ring a notch. When you come out of fwd, there should be a place where you're in neutral and the shaft doesn't turn (or perhaps turns slowly). This may not be where the shift lever is vertical. If you don't have a neutral position, your reverse adjustment is probably too tight. Also, there's no detent in reverse - just a wedge and a roller. Make them too tight, you shear the pin, and the roller and other parts go for a swim in your crankcase.
Finally, check your linkage for slop. I've got a big Morse cable, and the transmission end was almost floating free - made for interesting shifting! Even a bellcrank & rod system will act strange if things get sloppy.

Al

[HalfHourEarly]

Thanks Al

I have disengaged the linkage and am shifting the lever by hand. I think I will try loosening the reversing gear a little more but I am still confused as to why this would be happening all of a sudden when it was fine last fall when the boat was hauled out. I can understand a little adjustment but...

[NorfolkRagbagger]

HalfHourEarly: I have the A4 in a 79 Catalina, have to adjust the reverse it seems every few months. Never seen in this great forum why, nor have I asked (other more serious matters needed attention!) I believe it's temperature - ambient, engine, and play in shifter cable - but I adjust the dang thing every few months at least. Right now I'm adjusting because my forward and reverse seem to be overlapping - idle in gear at the pier, suddenly I'm in reverse! I'm not too concerned about this because over the past few months I've had everything apart, cable, fuel lines, exhaust - I probably jiggled something - but I've NEVER set it and had it stay right where I want it. The reverse gear is like an old dog - it's a pain, but you've had him forever and you get attached to it. In that way it's like a toothache, too.

Based on previous posts, I'm "backing off" the reverse right now to hopefully create a spread between F and R.


For the record, I just minutes ago backed the reverse shaft off half a turn (counterclockwise when looking at the left-side end) and I'm no longer going back and forth between F and R. Not much R right now, but forward stays in, doesn't pop out, and it's a world of better.

[Maurice]

Hi,

Didn't see it mentioned on this one but Don Moyer's MMI A4 manual has a great description, diagram, and procedure to set the reversing gear.

Best
mo