Gearbox failure - Help

[Pete & Helen]

I have a vetus engine coupled to a Technodrive TMC 60M gearbox.

All was well tootling along the canal when suddenly (without any bangs or any warning) lost all drive to the prop shaft.

 

All the controls are working and its selecting forward and reverse and engine will rev as it should do. Checked oil and thats ok. and one other thing, I have noticed before, and I am sure it happened when ever the engine was running. there is what could be described as the end of a shaft just protruding out of the rear of the gearbox, presumably in line with the input shaft which now doesn't move. The prop shaft also moves very freely.

 

I am right in thinking that there is a thrust plate or some arrangement between the engine and gear box that could cause this if it fails?

 

Is it hard to check and replace? Engine out job or lifting gear required??

 

At the moment I'm stuck on the Coventry canal nr Nuneaton if you just happen to be passing by.

[Traveller]

Cannot help with the technicalities even though I have the same gearbox. This link might be of some use though (I hope so)

 

Link removed wrong gearbox sorry - you said TMC not TMP

Edited October 26, 2015 by Traveller

[Tony Brooks]

Its a hydraulic box, have you checked the oil level?

 

I think those boxes had a problem with pop-rivets in the clutches at one time, not saying that is what it is but maybe worth discussing it with TMP.

 

It could be a drive plate but I would have expected some noise before complete failure, oil level is best bat at the moment.

[Traveller]

The OP does say he has checked the oil, Tony.

[Boat&Bikes]

Can't help much with the box, not one I'm familiar with. I am based in Nuneaton though with car so if your stuck for any tools or provisions just yell. Good luck . Ian

[Pete & Helen]

Can't help much with the box, not one I'm familiar with. I am based in Nuneaton though with car so if your stuck for any tools or provisions just yell. Good luck . Ian

 

Thanks Ian. Got RCR coming out to have a look. If I get stuck for anything I will let you know. Thanks again

[Tiggs]

 

 

All the controls are working and its selecting forward and reverse and engine will rev as it should do.

Is it hard to check and replace? Engine out job or lifting gear required??

 

How do you know it is selecting forward and reverse if the prop is not going round?

 

Is the lever on the side of the box moving forward and back fully 45 degrees?

 

If the gearbox is fault - sounds like a clutch failure - then it should be removable without removing the engine, easily lifted with a couple of blokes and some rope and wood.

[Tony Brooks]

The OP does say he has checked the oil, Tony.

I went back to re-read the thread and did not notice that either time.

[Traveller]

I went back to re-read the thread and did not notice that either time.

Not sure if that means you found it or not :-) But OP says:

"All the controls are working and its selecting forward and reverse and engine will rev as it should do. Checked oil and thats ok. and one other thing, I have noticed before, and I am sure it happened when ever the engine was running. there is what could be described as the end of a shaft just protruding out of the rear of the gearbox, presumably in line with the input shaft which now doesn't move. The prop shaft also moves very freely."

 

​Presumably the reference to oil is to gearbox oil.

[Tony Brooks]

Not sure if that means you found it or not :-) But OP says:

"All the controls are working and its selecting forward and reverse and engine will rev as it should do. Checked oil and thats ok. and one other thing, I have noticed before, and I am sure it happened when ever the engine was running. there is what could be described as the end of a shaft just protruding out of the rear of the gearbox, presumably in line with the input shaft which now doesn't move. The prop shaft also moves very freely."

 

​Presumably the reference to oil is to gearbox oil.

 

It means that during replying I went back to check that they had checked the oil level and both then and the first time I read it I missed it.

[mayalld]

I have a vetus engine coupled to a Technodrive TMC 60M gearbox.

All was well tootling along the canal when suddenly (without any bangs or any warning) lost all drive to the prop shaft.

 

All the controls are working and its selecting forward and reverse and engine will rev as it should do. Checked oil and thats ok. and one other thing, I have noticed before, and I am sure it happened when ever the engine was running. there is what could be described as the end of a shaft just protruding out of the rear of the gearbox, presumably in line with the input shaft which now doesn't move. The prop shaft also moves very freely.

 

I am right in thinking that there is a thrust plate or some arrangement between the engine and gear box that could cause this if it fails?

 

Is it hard to check and replace? Engine out job or lifting gear required??

 

At the moment I'm stuck on the Coventry canal nr Nuneaton if you just happen to be passing by.

 

Your diagnosis (drive plate) is almost certainly correct.

 

The symptoms match (the lack of rotation on the input shaft stub is the clincher), and Vetus fit drive plates that are crap.

 

It isn't an impossible task, and can be done with ropes and a bottle jack, so no lifting gear needed.

 

Basically, you undo the R&D coupling from the gearbox output, and undo the coupling from the prop shaft (to give more room), and slide the prop backwards (note how far into the coupling the shaft goes)

 

Use the bottle jack under the engine to support the weight, then remove the bell housing.

 

Unbolt the plate from the flywheel, and remove the splined portion from the gearbox spline.

 

New R&D driveplate, and reassemble in reverse order, checking alignment of the shaft, and off you go.

 

Take you about half a day.

[Guest]

 

Your diagnosis (drive plate) is almost certainly correct.

 

The symptoms match (the lack of rotation on the input shaft stub is the clincher), and Vetus fit drive plates that are crap.

 

It isn't an impossible task, and can be done with ropes and a bottle jack, so no lifting gear needed.

 

Basically, you undo the R&D coupling from the gearbox output, and undo the coupling from the prop shaft (to give more room), and slide the prop backwards (note how far into the coupling the shaft goes)

 

Use the bottle jack under the engine to support the weight, then remove the bell housing.

 

Unbolt the plate from the flywheel, and remove the splined portion from the gearbox spline.

 

New R&D driveplate, and reassemble in reverse order, checking alignment of the shaft, and off you go.

 

Take you about half a day.

agreed. If the visible shaft end at the rear of the gearbox has stopped rotating, there is no drive into the box. This rotates whenever the engine is running (or should do!) Almost certainly the drive plate. I have the drawings for this box somewhere and will post them.

 

Edited October 26, 2015 by Guest

[ROBDEN]

If I have read this correctley. Have a look at the split half coupling.

Push shaft back into coupling and re-tighten.

 

It's happend to me more than once.

 

Oh yeah! The TMC60 is a mechanical box.

 

Rob....

[ROBDEN]

 

Your diagnosis (drive plate) is almost certainly correct.

 

The symptoms match (the lack of rotation on the input shaft stub is the clincher), and Vetus fit drive plates that are crap.

 

It isn't an impossible task, and can be done with ropes and a bottle jack, so no lifting gear needed.

 

Basically, you undo the R&D coupling from the gearbox output, and undo the coupling from the prop shaft (to give more room), and slide the prop backwards (note how far into the coupling the shaft goes)

 

Use the bottle jack under the engine to support the weight, then remove the bell housing.

 

Unbolt the plate from the flywheel, and remove the splined portion from the gearbox spline.

 

New R&D driveplate, and reassemble in reverse order, checking alignment of the shaft, and off you go.

 

Take you about half a day.

Half a day? Not if it's a trad, there's no room to get the bottom bolts. You will need to find a very small person to get them.

Also the rear mounts are on the gearbox.

[Pete & Helen]

Update.

 

RCR engineer has been and thinks that it's a gearbox problem. I did point out the input shaft stub end wasn't rotating but this was over ruled as he thought that a failure of the drive plate would be noisy. So they are comming with a new gearbox tommorrow morning. Will wait and see what happens.

 

Thanks for you'd comments.

[ROBDEN]

I have a vetus engine coupled to a Technodrive TMC 60M gearbox.

All was well tootling along the canal when suddenly (without any bangs or any warning) lost all drive to the prop shaft.

 

All the controls are working and its selecting forward and reverse and engine will rev as it should do. Checked oil and thats ok. and one other thing, I have noticed before, and I am sure it happened when ever the engine was running. there is what could be described as the end of a shaft just protruding out of the rear of the gearbox, presumably in line with the input shaft which now doesn't move. The prop shaft also moves very freely.

 

I am right in thinking that there is a thrust plate or some arrangement between the engine and gear box that could cause this if it fails?

 

Is it hard to check and replace? Engine out job or lifting gear required??

 

At the moment I'm stuck on the Coventry canal nr Nuneaton if you just happen to be passing by.

Opps! Sorry. Missed that.

[ditchcrawler]

When my drive plate went it was changed by disconnecting the prop shaft and sliding it back, then removing the gearbox, the drive plate was changed through the hole where the gearbox covered. This was on a Beta engine.

[bizzard]

And what if it is only the drive plate, are you still going to let them fit a new gearbox. I'd watch them carefully in case it is just the drive plate. I think they should have removed the box today for inspection before stating that its the gearbox. Supposing it is the drive plate and they don't bring a new one with them. Drive plates do usually make a noise before and when they fail, but not always.

[bottle]

and , if I may, they should bring a new drive plate as it would be prudent to fit a new one if fitting a 'new' gearbox.

[Chris Davidson]

I'm no expert, but I do know that when our drive plate failed it did not make a noise.

So it could easily be a drive plate fault .

I would have thought that it would be easier to check that before replacing the complete gearbox.

[Guest]

Not impossible that the input shaft has sheared I suppose, but still thinking driveplate. If I was fitting a new box, I would fit a driveplate as a matter of course, just as I would want a new clutch in my car if the gearbox was being removed for any reason.

 

Either way, hope you are soon underway again.

Edited October 26, 2015 by Guest

[Bee]

I would also suspect the drive plate before anything else. I don't know these boxes but I wonder if there is a selector fork attached to the selector lever that has failed, seem strange to have no fwd or rev. so suddenly.

[Boat&Bikes]

If the input shaft isn't inputting how can the gearbox receive any drive? Is there a clue here? Ian .

[Guest]

If the input shaft isn't inputting how can the gearbox receive any drive? Is there a clue here? Ian .

That is my thought too. I know on our technodrive/Vetus that the shaft mentioned by the OP can be seen rotating from the rear whenever the engine is running. I can only think drive plate failure, followed by possible shaft failure. Knowing how these boxes engage gear, I would not rule the latter out. My money is on the drive plate though.

I would also suspect the drive plate before anything else. I don't know these boxes but I wonder if there is a selector fork attached to the selector lever that has failed, seem strange to have no fwd or rev. so suddenly.

There is a sort of fork on the other drawing which I will find.

 

Edited October 27, 2015 by Guest

[mayalld]

Update.

 

RCR engineer has been and thinks that it's a gearbox problem. I did point out the input shaft stub end wasn't rotating but this was over ruled as he thought that a failure of the drive plate would be noisy. So they are comming with a new gearbox tommorrow morning. Will wait and see what happens.

 

Thanks for you'd comments.

 

That is a VERY surprising diagnosis!

 

Sudden gearbox failure is rare. Drive plate failure common. I can say with certainty that when our drive plate failed (Vetus + TMC). it wasn't noisy.

 

As it fails, the hub part of the drive plate tends to shift up the spline a little, leaving the backplate spinning uselessly on the flywheel. It isn't fouling anything, so no noise.

 

Gearbox failure should only be considered after PROVING that the drive plate is OK.

Half a day? Not if it's a trad, there's no room to get the bottom bolts. You will need to find a very small person to get them.

Also the rear mounts are on the gearbox.

 

The rear mounts aren't a big problem.

 

When we did ours, I followed the following process;

 

Bottle jack to take rear loading of engine.

 

Slack the top mount nuts on rear mounts a little

 

detatch the rear mounts from the box, and swing them 180 degrees out of the way.

 

Much less trouble than trying to remove the box with mounts attached.