Delayed Gear Engagement - Forward Only

[Foswick]

I have Universal M35-B with only about 500 hours on it. The boat is new to me, this spring. The issue is that when shifting into forward, there is sometimes a slight delay for the gear to engage - usually about a second, but up to maybe 2 seconds. At least half the time, there is no delay at all. Reverse does not have this issue, ever.

The manual addresses this in a troubleshooting guide and suggests: Lever travel N to B not equal to N to A. Refer to diagram.

The suggested remedy: Adjust cover plate until the lever is exact mid-position. Refer to shift lever diagram and text.

OK, simple enough ... but after looking at the diagram and reading the text, it is still unclear to me what they mean. Here are the two diagrams to which they might be referring:

A couple of things occur to me. First, the cable should be centered in the neutral position. If it is adjusted such that it favors reverse, the shifting travel to forward might be just a tiny bit shy of where it needs to shift into forward. That makes some sense to me, but that should be an adjustment that can be made on the cable at either end. I have played with this adjustment on the shifter level (cockpit) end. In fact, I just replaced the shifting lever (for an unrelated reason) and adjusted the cable at that time. It performs exactly the same after the replacement/adjustment as it did before.

So, when they talk about A <--> N being the same as B <--> N, if I am understanding correctly, that should be a matter of fine-adjusting the cable length.

But, the manual talks about adjusting the cover plate until the lever is exactly mid-position. I see "cover" labeled on their diagram, but I have no idea what they are talking about or how adjusting it would address the issue. It doesn't help that this part of the transmission is on the side of the engine compartment that is almost completely inaccessible and almost unviewable.

I will add one more clue. She idles high. The recommended range is 800-1000 and she idles at a bit over 1100 (by the instrument, not by direct measurement). Intuitively, it "feels" like that is the issue - that she idles just right at the threshold above which she won't shift, but below which she will. When shifting back and forth (such as with a standing turn), there is a sense that she needs to settle a bit before she will fall into forward. It isn't much - like it needs to settle down from 1100 RPMs to 1095. That is, I am pausing in neutral, as normal, but it seems like she needs just an extra couple of seconds to fully settle down to that threshold RPM.

I need to address the idling issue anyway because the idle adjustment screw is adjusted all the way down and she still idles a bit high. So, that has to happen whether it is the cause of the shifting problem or not. And, that might just fix it.

But, I was hoping someone could help me understand what they are saying about the cover plate.

 

[dlochner]

But, the manual talks about adjusting the cover plate until the lever is exactly mid-position. I see "cover" labeled on their diagram, but I have no idea what they are talking about or how adjusting it would address the issue. It doesn't help that this part of the transmission is on the side of the engine compartment that is almost completely inaccessible and almost unviewable.

I think the plate they are talking about is the cover that is bolted to the transmission with 4 bolts. The position of that affects the cam inside and how the interacts with the internal shifting. I was once told by the transmission mechanic to never touch those bolts. He had just rebuilt the transmission and I was going to install it.

So, when they talk about A <--> N being the same as B <--> N, if I am understanding correctly, that should be a matter of fine-adjusting the cable length.

I thought this too once upon a time. The fine tuning adjustment only works in neutral to get the cable to the exact length necessary. The necessary length is reached when the midpoint of the rod's extension out of the cable jacket. At this point the amount of cable throw will be equal fore and aft.

Try these steps.

1. Fully extend the rod, detach from the shift lever if necessary.
2. Put the transmission lever in neutral. Do not move it again until you are done.
3. Find the exact midpoint of the cable throw on the rod and mark with a sharpie.
4. Connect the cable to the shift lever and place in the neutral position.
5. Now, adjust the cable length with the fine adjustment fittings so that the cable ends attach in the correct places and the mark made for the cable throw midpoint is just peeking out of the cable.
6. Tighten everything up so nothing moves.
7. Test the fitting, by engaging the transmission with the engine running. This can be done at the dock. Gear engagement should be very solid and the throw should be equal between forward and reverse.

In the transmission the shift lever is connected to a cam, once it put the tranmission in gear, the cam is not touching anything until the shifter is pulled back and the cam engages with the transmission and takes the transmission out of gear.

At least on my transmission, and I think all marine transmissions, when the lever is upright pushing it forward puts the boat in reverse and pulling back puts it in forward with a right hand drive.

Figuring all this out took several very hot and tiring days sitting in the travel lift well. Eventually I was towed to my slip, where I finally figured it oul

Good Luck!

 

[dmax]

While you're at it, change the transmission fluid - always helps.

 

[Foswick]

I think the plate they are talking about is the cover that is bolted to the transmission with 4 bolts. The position of that affects the cam inside and how the interacts with the internal shifting. I was once told by the transmission mechanic to never touch those bolts.

That was my tentative conclusion as well. And, the diagrams kind of support this. Unfortunately, the parts diagrams/catalog make no mention of this part. I wish I could get a better look at it, but it is really tucked away in a hard-to-reach spot.

Thank you for the thorough response.

 

[Ward H]

I went thru this when diagnosing my Hurth HBW 50 (IIRCC) tranny, then again when I installed the TMC 40 tranny.
First thing I did was take off the shift cable and checked the throw of the shift lever on the tranny, making sure it was in dead neutral when at straight up/ 90 from horizontal. On my TMC 40 the shifter was on the port side so to keep the shift direction the same I had to loosen and rotate the shift lever 180 to the bottom, ensuring the it was in dead neutral when 90 below horizontal. I loosed the shift lever using the bolt that clamped the lever to the shifter shaft.

Then I had to adjust the throw of the shift cable to ensure it met or exceeded the throw of the shift lever.
I then determined the center of the throw distance on the cable and clamped it down so the center of the throw matched the center of the shift lever.

But, the manual talks about adjusting the cover plate until the lever is exactly mid-position.

I don't see that. It talks about clearance between the shift lever and cover plate but that is by moving the shift lever on the shifter shaft, not the cover plate. It also talks about adjusting the shift lever as I needed to do, moving it to another position.

 

[Davidasailor26]

One thing you didn’t say you checked - If you disconnect the cable and shift the transmission with the lever manually does it always shift reliably? I’m concerned that you may already have some clutch wear that, in the words of the diagram, “would be indicated by slow clutch engagement.”

Also, if the idle screw is already all the way down and the engine is still idling at 1100 you may want to check the RPMs with an optical tach. Just wouldn’t want you to go through a lot of work to bring the idle even slower if your tach is reading off.