How do you stop a reverse gearbox jumping out of gear?

Steven · Post by **Steven** » Sun Jul 26, 2009 4:06 pm

I have a Model 90 which I have been using for the last 5 years without any problem and recently bought a 170 in almost unused condition.

The 170 and 90 seem to have identical gearboxes but with different props.

My problem is that my 170 will not stay in gear - it engages and drives but if you do not hold the gear lever in position it simply jumps back into neutral.

I'm not sure where to start and none of the bolts look like they have ever had a spanner on them so I'm not keen to break the paint seal on things that don't help this problem. Can anybody help?
Thanks Steven

niander · Post by **niander** » Sun Jul 26, 2009 5:24 pm

afraid i know nothing of this model but

none of the bolts look like they have ever had a spanner on them

That is good!
it means no bodge artist has been inside it!
and they could have been rounded off by the same guy etc

sure someone will offer you advice soon...

Steven · Post by **Steven** » Sun Jul 26, 2009 7:19 pm

Thanks for the reply Niander.

I took the gear box oil filler plug out and all looks well in there. Oil is up to the correct level and looks very clean.

I replaced its remote set up with a tiller and thumb throttle. With the remote set up, it would have been kept in gear by the tension of the remote gear cable but my model 90 stays in gear quite happily, although it does go into neutral if you kill the engine in gear.
Steven

Post by **RickUK** » Mon Jul 27, 2009 8:56 am

Steven - don't worry about it - these boxes disengage without any drive on, and therefore pressure on the prop. If you try it in a test tank or on a boat, all should be well. Rick.

Steven · Post by **Steven** » Mon Jul 27, 2009 11:08 am

Cheers Rick - that sounds very encouraging. Wheelie Bin #3 gets emptied tomorrow so I'll give it a test in that. I've never noticed this with my 90.

I'm going to give first refusal on the remote set up for a 170 to this forum if anybody is interested - check the "for sale" pages. Includes remote throttle lever, correct throttle cable, cable retaining fixing, linkage frame for gear, throttle and tiller cables as well as the remote cabling and control box. Everything that is required apart from the wheel!

Steven

Waggles · Post by **Waggles** » Tue Aug 04, 2009 8:31 am

Steven,

My 90 behaves much the same as yours, will stay in gear OK but will jump out when stopped in gear which seems to agree with Rick, don't think it should jump out while driving though.

If it does I would first check the linkage and pivot bolt to make sure it is fully engaging the gear. I have noticed the linkage rod can flex quite a bit under strain so if it is binding in the top of the gearbox to some extent that may cause it not to engage properly too. As you have just changed the linkage It makes me think the problem could be there.

If thats OK then the only thing I can think of is a worn or damaged clutch dog. Don't have enough experience yet of these boxes to know if that is likely.