Gearbox's
There are two main types of gearbox's used on narrowboats, mechanical and hydraulic. In either case, overheating and slipping are probably your most likely problems.
In both cases, check the oil level, and reduce power, In most cases going at half speed will stop the box slipping temporarily which should be enough to get you where your going.
For me, when it comes to Gearbox's for narrowboats PRM are king.
The mechanical boxes tend to be noisier at idle or low revs and harder to shift gears than the hydraulic equivalent.
A PRM 120 is a manual box, small, light, rattily, harder to shift but is excellent value for money at £250 gets a good used one.
If buying second-hand check for Black oil or silver streaks this shows overheating and high wear respectively.
A box that won't drive the prop, often can be a broken linkage not operating the gear lever, or a broken drive plate, to check if its either of these. Remove the dipstick and see if anything is moving in the box at all, If it isn't then its usually a drive plate failure. (The primary shaft should always be turning with the engine unless the drive plate is broken).
Quite a lot of boxes' have a 'get you home' facility where the clutch plates can be tightened to keep you going for a little while, check your manual!
Don't be scared of removing the box, taking it home and working on it, there's only two shafts in it - you CAN screw it up, but with care you should be ok.
In both cases, check the oil level, and reduce power, In most cases going at half speed will stop the box slipping temporarily which should be enough to get you where your going.
For me, when it comes to Gearbox's for narrowboats PRM are king.
The mechanical boxes tend to be noisier at idle or low revs and harder to shift gears than the hydraulic equivalent.
A PRM 120 is a manual box, small, light, rattily, harder to shift but is excellent value for money at £250 gets a good used one.
If buying second-hand check for Black oil or silver streaks this shows overheating and high wear respectively.
A box that won't drive the prop, often can be a broken linkage not operating the gear lever, or a broken drive plate, to check if its either of these. Remove the dipstick and see if anything is moving in the box at all, If it isn't then its usually a drive plate failure. (The primary shaft should always be turning with the engine unless the drive plate is broken).
Quite a lot of boxes' have a 'get you home' facility where the clutch plates can be tightened to keep you going for a little while, check your manual!
Don't be scared of removing the box, taking it home and working on it, there's only two shafts in it - you CAN screw it up, but with care you should be ok.
