Gearbox failure - Help

[Guest]

 

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.

 

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.

The rear mounts are actually on the adapter/bellhosing on our engine (Vetus 415) and as you imply can be swung clear when a jack is used. I always keep a cheap scissor jack on the boat for these jobs (a very useful tip given to me by DOR of this parish.)

Edited October 27, 2015 by Guest

[ROBDEN]

 

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.

 

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.

It obviously has a lot to do with access.

 

When changing my drive plate (4.17 after sounding like a bag of spanners) there was no room for any sort of jack.

Had to put a joist across the rear slider and block and tackle to the lifting bracket on top of the engine.

Then laying upsidedown with long extensions to get to the bottom bolts of the gearbox....I hate boats.

 

Rob....

[Guest]

It obviously has a lot to do with access.

 

When changing my drive plate (4.17 after sounding like a bag of spanners) there was no room for any sort of jack.

Had to put a joist across the rear slider and block and tackle to the lifting bracket on top of the engine.

Then laying upsidedown with long extensions to get to the bottom bolts of the gearbox....I hate boats.

 

Rob....

That sounds like my previous boat.....

Not doubting what you say in any way, but surprised a scissor jack wouldn't go in. That's boats for you

That is why the good lord gave us scaffold poles and rope

[Pete & Helen]

Update:-

 

RCR phoned this morning and said that their engineer couldn't do the job till next week but could arrange a contractor to come out. When? I asked, they couldn't say. I did reiterate that I wasn't happy with the diagnosis of their engineer and they said that if the contractor confirmed it was the gearbox then I would have to pay his call our charge, but if it was the drive plate then they would pay. Decided to sort it out myself so called Richard of this parish and he is coming tomorrow morning to sort it out.

Update after fixed so you will know what the cause was

[Traveller]

This after they said they would be back today?

[ditchcrawler]

Funny, up until about a year ago I never heard a bad word said about RCR

[frangar]

I thought their cover included gearboxes? In my experience they do seem keen to replace parts that aren't covered by their policy....I wonder why that is.....?

 

Cheers

 

Gareth

[Boat&Bikes]

I thought their cover included gearboxes? In my experience they do seem keen to replace parts that aren't covered by their policy....I wonder why that is.....?

Cheers

Gareth

They have different levels of cover. Not sure whats covered, I thought gearboxes were included at some level too The OP hasn't said that they were going to charge for a new box has he? Only for a call out cost. We haven't used RCR for several years but I know two boats that were helped by them recently. Both received excellent service. Lets not start another witch hunt please.

 

Ian.

[dor]

All RCR levels of cover (except their very basic one) cover parts including gearbox. As a new gearbox will cost you close to £1K I would let them replace the gearbox. Then if it turned out to be the drive plate replace that as well.

 

If you really are going to do it yourself I would strongly recommend replacing the TMC60 with a PRM150. It is almost a straight replacement, just a few mm difference in drop and length. The basic change over took me about two hours, plus another couple of hours later on to fit the oil cooler.

[Guest]

All RCR levels of cover (except their very basic one) cover parts including gearbox. As a new gearbox will cost you close to £1K I would let them replace the gearbox. Then if it turned out to be the drive plate replace that as well.

 

If you really are going to do it yourself I would strongly recommend replacing the TMC60 with a PRM150. It is almost a straight replacement, just a few mm difference in drop and length. The basic change over took me about two hours, plus another couple of hours later on to fit the oil cooler.

Having seen DOR's Vetus installation, and the difference in engaging gear compared to the Technodrive, it would certainly be a smart move.

[RLWP]

Driveplate

 

Richard

[frangar]

Driveplate

 

Richard

 

Thanks for letting us know……Still wondering why RCR wanted to fit a new box??…..especially if the cost was going to be covered under the policy.

 

Cheers

 

Gareth

[Schipper]

This box has twin conical clutches(forward/ reverse).When ours failed I was still able to use reverse.

It seems a bit odd that they both failed at the same time??

 

 

 

Geert

[mayalld]

 

Thanks for letting us know……Still wondering why RCR wanted to fit a new box??…..especially if the cost was going to be covered under the policy.

 

Cheers

 

Gareth

 

Unless I am mistaken, RCR don't have salaried engineers.

 

rather, they have a series of independent mechanics, who work for them, and get paid for work done.

 

The consequence being that the mechanic has a vested interest in making it into a big job, and the boater doesn't actually care whether it is or not.

This box has twin conical clutches(forward/ reverse).When ours failed I was still able to use reverse.

It seems a bit odd that they both failed at the same time??

 

 

 

Geert

 

Drive plate is between the engine and gearbox, not inside the box

[Schipper]

I'm always keen to learn,how do I operate the drive plate??

I only got one cable from my selector going to the gearbox,selecting forward or reverse and one to the throttle.

Is our boat missing a clutch padle???

 

Geert

[Traveller]

Will the OP be informing RCR of the erroneous diagnosis?

[Tony Brooks]

I'm always keen to learn,how do I operate the drive plate??

I only got one cable from my selector going to the gearbox,selecting forward or reverse and one to the throttle.

Is our boat missing a clutch padle???

 

Geert

 

No, its not. The gearbox is deigned so the gear engagement is done through clutches of one type or another or brake bands, Mechanical boxes tend to use a sort of "super synchromesh" cone clutches nowadays although older ones used multi-plate clutches. Hydraulic boxes use multi-plate or cone clutches with older ones using a brake band for reverse. They will all slip to a degree when they are initially engaged providing a relatively smooth take up of power.

 

The drive plate is a bit like a car's clutch centre plate but made of steel. This is bolted to the flywheel and rives the gearbox via splines.

[David Mack]

I'm always keen to learn,how do I operate the drive plate??

I only got one cable from my selector going to the gearbox,selecting forward or reverse and one to the throttle.

Is our boat missing a clutch padle???

 

Geert

 

The drive plate simply connects the engine crankshaft/flywheel to the gearbox input shaft, so you don't operate it yourself. Its located where the clutch would be on a car engine.

 

A marine gearbox has two internal clutches - one for forward drive and one for reverse, so you just push the selector lever one way from the central position for forward and the other way for reverse.

Edited October 28, 2015 by David Mack

[RLWP]

 

Unless I am mistaken, RCR don't have salaried engineers.

 

rather, they have a series of independent mechanics, who work for them, and get paid for work done.

 

The consequence being that the mechanic has a vested interest in making it into a big job, and the boater doesn't actually care whether it is or not.

 

That isn't quite correct. They do have a handful of salaried engineers, the ones I have met are good. They also have relationships with contractors who do work for them - me for instance

 

For future reference, the engine is a Vetus M4.15, the gearbox is a Technodrive TMC60 and the R&D equivalent driveplate is an RD22AM37. There, that should Google nicely

 

This plate has a million* little holes around the periphery and will fit a variety of engines. And gearboxes for that matter, using a standard ten tooth spline

 

I'd like to sing the praises of Midland Chandlers who sorted out a driveplate PDQ for me. Nice work guys

 

Richard

 

*give or take a few factors of ten

[Pete & Helen]

Well looks like you have all done the description to death so won't ponder that point.

Richard has given you the info on the replacement part. The only difference being that it has as he said multiple holes so it will fit loads of boxes and in place of damper springs it uses a plastic looking material (not sure what it is) which no doubt will last. Having said that, if this is the first drive plate change then the old one lasted 5000 engine hours which is not bad going.

 

Big thanks to Richard fo doing such a speedy job.

 

Oh and told RCR that they made a mistake in their diagnosis. So hope that gets to whoever needs to know. Didn't speak with the same person that was dealing with the job so didn't bend her ear too much. I wonder if they will ask me to fill in a satisfaction survey? Maybe not :-)

Edited October 28, 2015 by Pete & Helen

[Guest]

 

That isn't quite correct. They do have a handful of salaried engineers, the ones I have met are good. They also have relationships with contractors who do work for them - me for instance

 

For future reference, the engine is a Vetus M4.15, the gearbox is a Technodrive TMC60 and the R&D equivalent driveplate is an RD22AM37. There, that should Google nicely

 

This plate has a million* little holes around the periphery and will fit a variety of engines. And gearboxes for that matter, using a standard ten tooth spline

 

I'd like to sing the praises of Midland Chandlers who sorted out a driveplate PDQ for me. Nice work guys

 

Richard

 

*give or take a few factors of ten

Thanks for info, drive plate number is handy since I have this setup.

I have always had great service from Midland Chandlers.

May I ask what sort of time the job took?

Cheers.

[RLWP]

A few hours. As usual, twice as long to remove as to fit. I knew where and what size the bolts were putting it back

 

Richard

[mayalld]

I'm always keen to learn,how do I operate the drive plate??

I only got one cable from my selector going to the gearbox,selecting forward or reverse and one to the throttle.

Is our boat missing a clutch padle???

 

Geert

You don't operate a drive plate.

 

It is just there instead of a clutch to absorb the jolt as gear is engaged

[Guest]

A few hours. As usual, twice as long to remove as to fit. I knew where and what size the bolts were putting it back

 

Richard

Cheers.

Nearly always quicker reassembling

Never worked out how to get the blood back in my fingers though

[RLWP]

I forgot to say - good gig! Two mugs of tea and cake!

 

Richard