Difficulty engaging forward gear - Beta 30

[LittleSister]

A quick update: I changed the gear box oil, which didn't seem to have any effect. I have then been trying to play around with the gear cable as I think this may be the issue: when going into forward, the gear lever does not seem to have made its entire range of motion into gear before throttle starts being applied; after throttle is applied, the gear level makes an additional ~5mm movement. This makes me think that the issue may be with the gear cable and that the gearbox is being made to put the engine into gear at too late a stage (i.e. when the engine revs are too high).

This brings me to a new question: How does one adjust the engagement point for forward without it throwing the engagement point for reverse out of sync? It seems to me that the only way to make the engine engage forward earlier is to shorten the gear cable, but this will then mean reverse is engaged later. Am I doing something wrong?

Thanks for the additional input folk.

A final update: I checked out the gear cable and I don't believe this is the issue - forward and reverse were engaging in exactly the same way with the cable attached as they were when I disconnected the cable and was manually putting the engine into forward / reverse using the gear lever on the gearbox. That said, I was using the boat the past couple of days and the situation seems somewhat improved - maybe the change of oil or the tightening up of some of the nuts and bolts has made a difference. Regardless, I think at this point all that's left for me to do is to monitor the situation and engage an expert (and possibly replace the gearbox) should it start to play up more seriously.

I really appreciate all the help. Wouldn't have even known the first place to begin in trying to troubleshoot the issue. Many thanks!

I don't understand how it can be both as you describe in your earlier report and in your more recent update.

In the earlier post you said that in forward the lever on the gearbox was moved a further 5mm after the throttle was applied. This is, if correct, a really important clue as to what may be (and what is not) the problem. If you were later operating the gearbox manually (i.e. at tickover, and not connected in any way to the throttle) how can the lever subsequently be moving that extra 5mm?

Ignoring your update for the moment, and focusing on the additional 5mm movement. Can you confirm whether you have a single lever engine control (same operating lever controls both gear selection and reverse) or separate gear and throttle levers?

I can't see that the cable being out of adjustment would result in that extra 5mm movement. (That's not to say you shouldn't check that adjustment anyway, to eliminate additional complications and confusions, ensuring that when control lever is set to neutral, the lever on the gearbox is held by the cable exactly central, and doesn't have a different distance to travel to get properly into forward or reverse.)

The additional movement is, it seems to me, the result of one of the following potential problems:
a) GEAR CABLE MOUNTING - If the mounting for the cable outer sleeve termination at the gearbox end is not rock solid (i.e firmly fixed in position relative to the gearbox), it could be moved backwards and forward, which will mean that the cable inner attached to the gearbox lever will vary in both distance travelled and force applied.
b) SINGLE CONTROL LEVER FOR DIRECTION AND SPEED - there is something amiss with the single lever control which is not moving the gear cable equally depending on whether you select forward or reverse. The gear cable should be moved exactly the same distance (albeit in different directions) whether forward or reverse, and that movement should be completed before the single control lever starts to move the throttle cable to increase revs from tickover; or
c) SEPARATE CONTROL LEVERS FOR DIRECTION AND SPEED - there is something amiss with the gear control lever (throttle lever is irrelevant) which is not moving the gear cable equally depending on whether you select forward or reverse. The gear cable should be moved exactly the same distance forward and backwards; or
c) GEARBOX INTERNAL ISSUE - I think this is unlikely, but there could be both (i) something internal to the gearbox that is (initially?) resisting the full travel the cable is trying to achieve in forward, and (ii) some 'slack' somewhere in the cable system (including mountings, cable condition and operating lever) that means that resistance isn't (fully) transferred to the operating lever (and only belatedly overcomes the gearbox resistance as a result of vibration or whatever?).

Suggested further checks -
1) Can you move the gear cable outer mounting (at the gearbox end) at all by shoving it towards and away from the gearbox?
2) Disconnect gear cable from gear change lever on gearbox (a) Check does the gear cable travel at the gearbox end, from operating lever in neutral to forward the same distance as from neutral to reverse, and (b) Check whether the distance the lever on the gearbox can be moved from central (neutral) to fully forward equals the distance from central to fully reverse.
3) Replace gear change cable - might well make no difference, but will eliminate complications and confusing any other issues, and importantly is much easier and less costly than rebuilding/replacing the gearbox (which currently we can't say is the problem anyway, so could be pointless).