TMC40 gearbox

[George Silver]

Hi Folks,

 

I have a problem with a TMC 40 M gearbox which is fitted to a 21hp nanni dieasel on a 32ft sea otter. Once the throttle is moved forward to engage forward gear, there is a delay of about 20 seconds - a loud 'click' the gearbox engages and the boat moves forward. Any idea what the problem could be.... do I need a new gearbox ? if so is it easy to fit ?

 

kind regards,

George Silver

[rover220]

Hi Folks,

 

I have a problem with a TMC 40 M gearbox which is fitted to a 21hp nanni dieasel on a 32ft sea otter. Once the throttle is moved forward to engage forward gear, there is a delay of about 20 seconds - a loud 'click' the gearbox engages and the boat moves forward. Any idea what the problem could be.... do I need a new gearbox ? if so is it easy to fit ?

 

kind regards,

George Silver

 

check box oil as a first call.

[churchward]

I guess it could be an internal selector issue in the gearbox. However, before you went down what could be an expensive route to fixing your problem there may be an alternative answer?

 

Could it be a cable issue I wonder? Perhaps the cable has stretched or is damaged. It may just need a bit of adjustment.

 

I say this as I have just fitted a new cable to my gearbox and before I did I had a similar symptom to yours but on selecting reverse. The old cable was a bit heat damaged (must have rested on a non protected exhaust pipe at one time before I bought her) but now with the new cable fitted and set right it engages drive in forward and reverse just as you would want, without any delay or chunkiness.

[steelaway]

Hi Folks,

 

I have a problem with a TMC 40 M gearbox which is fitted to a 21hp nanni dieasel on a 32ft sea otter. Once the throttle is moved forward to engage forward gear, there is a delay of about 20 seconds - a loud 'click' the gearbox engages and the boat moves forward. Any idea what the problem could be.... do I need a new gearbox ? if so is it easy to fit ?

 

kind regards,

George Silver

 

 

Hi

 

Will it go into reverse easily?

 

Alex

[George Silver]

Hi

 

Will it go into reverse easily?

 

Alex

 

Hi Alex thanks for the reply,

 

Yes she goes into reverse easily... every time without fail... just forward being the problem withthe delay in 'take up / egagement'.

 

check box oil as a first call.

 

checked the oil..... its got some in altho there is a red label on the box 'ATF only' and what is in in definatly isnt... (clear as opposed to ATF's reddish tinge). I have looked at a comment on the forums where it is debated to which oil to ude in a TMC 40 ???

 

I guess it could be an internal selector issue in the gearbox. However, before you went down what could be an expensive route to fixing your problem there may be an alternative answer?

 

Could it be a cable issue I wonder? Perhaps the cable has stretched or is damaged. It may just need a bit of adjustment.

 

I say this as I have just fitted a new cable to my gearbox and before I did I had a similar symptom to yours but on selecting reverse. The old cable was a bit heat damaged (must have rested on a non protected exhaust pipe at one time before I bought her) but now with the new cable fitted and set right it engages drive in forward and reverse just as you would want, without any delay or chunkiness.

 

I have checked the cable which 'appears' to be ok..... but Im no engineer.....

[steelaway]

Hi Alex thanks for the reply,

 

Yes she goes into reverse easily... every time without fail... just forward being the problem withthe delay in 'take up / egagement'.

 

 

 

checked the oil..... its got some in altho there is a red label on the box 'ATF only' and what is in in definatly isnt... (clear as opposed to ATF's reddish tinge). I have looked at a comment on the forums where it is debated to which oil to ude in a TMC 40 ???

 

 

 

I have checked the cable which 'appears' to be ok..... but Im no engineer.....

 

 

Hi Goerge

 

I think it was one of these 'boxs I fixed for a chap on the cut last month.

He had the same problem.

The cure was to centralise the change lever between foward and reverse by adjusting the cables, they were moving the lever to far into the reverse direction but not far enough in the forward direction.

This was almost successful but I then had to move the cable on the morse control to the end of the pivot lever to maximise the lever travel (it was in the centre hole of the lever) to increase the travel by maybe 1/2"

You are only moving the selector dogs close to the forward gear and it takes time for the drive dogs to be pulled into the drive gear. The drive dogs are under cut at about 30 degrees (like mortice joint) so that they get pulled into the drive gear.

I hope this helps.

 

Alex

[George Silver]

Hi Goerge

 

I think it was one of these 'boxs I fixed for a chap on the cut last month.

He had the same problem.

The cure was to centralise the change lever between foward and reverse by adjusting the cables, they were moving the lever to far into the reverse direction but not far enough in the forward direction.

This was almost successful but I then had to move the cable on the morse control to the end of the pivot lever to maximise the lever travel (it was in the centre hole of the lever) to increase the travel by maybe 1/2"

You are only moving the selector dogs close to the forward gear and it takes time for the drive dogs to be pulled into the drive gear. The drive dogs are under cut at about 30 degrees (like mortice joint) so that they get pulled into the drive gear.

I hope this helps.

 

Alex

 

Hi Alex,

 

thankyou very much for the information - I'll endeavor to give it a go 1 - are you an engineer for hire ??? . the morse control I have is an 'MV-2' which I have been advised have 'slipping issues' on sea otters ??? so this could well be the culprit altho most owners complain of engine revs slipping.

 

cheers

George