Technodrive TM170 TM880A, TwinDisk engaging failure, low hours

[vas]

hello,

had a very UK day on the boat (thank god without wife and kids) being the race committee boat for a raggie 25nm race.
Started nicely with a F5 and pissing down with rain on our back edging F6 on the middle of the route and dropping to a F3 as reached the end.
Did half an hour planning at 16-17kn, then an hour or so displacement but one of the guys was rather fast so had to rush to the finish line (which we had to setup). Anyway, second time on the plane doing 17kn and after 10mins lost power, dropped speed and port engine reved up to 2400 (was running at 2200rpm). Thought the worse engines neutral, went down everything looked fine (both engines there, both props there slowly turning) continued at 6kn scratching my head and boat steering to port. Didn't have much time to consider as the saily things were approaching, moored stern to on a designated spot with engine looking like working fine on reverse,

After the race was over went down to check levels, both engines and gboxes were fine filled to the max line.
Slightly puzzled, checked the cable runs and lever on top of the box movement and all is fine and identical to stbrd engine.
After a decent lunch we set off for the return trip only to find that indeed port engine does practically bugger all on fwd and thankfully works fine on reverse (don't want to think how I'd moor the Med way back at home port)
Now I have to admit that gboxes are NOT my strong point, it's the only part of a car I've never taken apart and definitely not on a boat.
I think the box is a Technomarine or something like that I'll take a clear pic of the box and the label tomorrow.

A knowledgeable friend says that since I do have reverse, it's unlikely it's a serious failure and started mumbling something about the threeway valves that route the oil from the pump to either front or back plates and other strange things.
Same guy also recons that it's highly unlikely that the fwd plates/disks are worn.
Mind engine has 620h or so.

Opinions?

cheers

V.

 

[superheat6k]

Re: port gearbox works only on reverse

I would check first that the selector cable is properly attached. Assuming it is a hydraulic box the selector is simply a lever operating an internal diverter valve to send oil under pressure to one of two clutches. If the cable has come loose perhaps it isn't setting the lever to the correct position in Ahead.

Techno marine could be Technodrive or perhaps Twin disc. I have manuals for the latter, model MG502, which were common with Volvo Penta TAMD60 series.

 

[vas]

Re: port gearbox works only on reverse

thanks,

it is indeed a Technodrive and cable does the full movement unobstructed, and the axle underneath moves (i.e. lever NOT slipping against the axle or anything silly like that)


Exact specs from the label on the box are:
Type: TM 880/A
Ratio: 2
Serial: 118006 (port) 18011 (stbrd)

looks like this (excuse the filthiness, but haven't actually done a decent clean around the engines and boxes yet)

I realize there is a sender on each box, but was never connected and have no gauge for it. Looks like the oilpressure and boost gauge VDO ones I have already wired up. I could switch the cables over from the oil pressure to this sender and see if it comes up with anything decent on fwd compared to rev. Thing is I don't know if this sender has similar psi range to the engine oil pressure one and if the pressure is there no matter if the diverter works to either fwd or rev...

Else I'll probably remove the assembly underneath the lever where the cable mounts and see what's in there. Would be nice to have a manual ofcourse, will see if I can get something from google.

cheers

V.

 

[kashurst]

Re: port gearbox works only on reverse

sounds like the forward clutch has failed. I don't think theres anything wrong with the oil pressure as you can use reverse. Either way its gearbox off time. Still winters coming, once you have got it off take back home and take it apart in the garage? Gearboxes aren't that difficult., just need shimming correctly to make sure they don't whine. I doubt yours is materially worn re bearings clearances etc. so just taking it to bits, replacing the clutch parts and it should be good to go. or see if you can get a recon unit.

 

[superheat6k]

Re: port gearbox works only on reverse

Vas

I haven't found a manual for your box yet, but on the Twin Disc the oil pressure is ~300psi, so way above engine oil pressure, but as astern is working OK I doubt that is the problem.

In your photo the selector cable mount plate is bent downward half way along, and as a result the cable connection is misaligned - is this the same on both boxes ?

With the cable set up like this the push away position would work ok as it is further from the cable mount clamp so would be taken up by cable flex, but the pull position could bind possibly preventing full free movement of the selector lever toward the cable (to the right in your picture).

If I find the manual I will send you a link.

 

[MapisM]

Re: port gearbox works only on reverse

Would be nice to have a manual ofcourse, will see if I can get something from google.

Your wish is my command! :encouragement:
My understanding, after googling around in IT a bit, is that your 880 gearbox is just the 10 degrees downward angled version of the 170 model (straight shaft), whose manual you can find here:
http://allpa.nl/media/manuals/Techn...orkshop Manual TM 170 - TM 170A - TM 880A.pdf
One thing I noticed while searching is that torsional compatibility is frequently mentioned as a critical point for this gearbox, specifying that torsion-induced vibrations could damage the thing.
I hope this isn't your case...

 

[vas]

Re: port gearbox works only on reverse

sounds like the forward clutch has failed. I don't think theres anything wrong with the oil pressure as you can use reverse. Either way its gearbox off time. Still winters coming, once you have got it off take back home and take it apart in the garage? Gearboxes aren't that difficult., just need shimming correctly to make sure they don't whine. I doubt yours is materially worn re bearings clearances etc. so just taking it to bits, replacing the clutch parts and it should be good to go. or see if you can get a recon unit.

Looks like I have to first establish that the diverter (3way?) valve works so oil pressure does push the plates and is not restricted somehow. Haven't seen drawings so haven't got a clue.
That aside, yes it's a box off and a few happy evenings at the garage
Good thing that it's only around 50kg (only specs I've found...)
Anyone able to confirm that 600h is normal for a set of disks as it seems to me that's a bit too early, no?

Vas

I haven't found a manual for your box yet, but on the Twin Disc the oil pressure is ~300psi, so way above engine oil pressure, but as astern is working OK I doubt that is the problem.

OK, that's off the list then, thanks!

In your photo the selector cable mount plate is bent downward half way along, and as a result the cable connection is misaligned - is this the same on both boxes ?

With the cable set up like this the push away position would work ok as it is further from the cable mount clamp so would be taken up by cable flex, but the pull position could bind possibly preventing full free movement of the selector lever toward the cable (to the right in your picture).

yep, both are a bit abused but since I checked (with a guy working on the levers) that all the travel is there and identical on both boxes I didn't bother. It's cosmetic in my book and got quite a few things above in the todo list...

If I find the manual I will send you a link.

thanks I'd very much appreciate it.

cheers

V.

 

[vas]

Re: port gearbox works only on reverse

Your wish is my command! :encouragement:
My understanding, after googling around in IT a bit, is that your 880 gearbox is just the 10 degrees downward angled version of the 170 model (straight shaft), whose manual you can find here:
http://allpa.nl/media/manuals/Techn...orkshop Manual TM 170 - TM 170A - TM 880A.pdf
One thing I noticed while searching is that torsional compatibility is frequently mentioned as a critical point for this gearbox, specifying that torsion-induced vibrations could damage the thing.
I hope this isn't your case...

thanks a lot MM!
saved me the thoughts of opening the thing up, bloody hell, that's a real mess! I see 100ton presses, precision tools, 9 disks, heating up bits to 120C before refitting, nah, don't think so!
Hope it's the top assembly, if not goes to a specialist.

cheers

V.

 

[NorthUp]

Re: port gearbox works only on reverse

Drain the gearbox oil, or possibly just look at the oil on the dipstick- wipe it on a clean white rag or kitchen roll.. The brass filings you will probably see are from the ahead clutch plates.
The control valve is very unlikely to be faulty.

 

[vas]

Re: port gearbox works only on reverse

Drain the gearbox oil, or possibly just look at the oil on the dipstick- wipe it on a clean white rag or kitchen roll.. The brass filings you will probably see are from the ahead clutch plates.
The control valve is very unlikely to be faulty.

when I wiped 4-5 times the dipstick on clean kitchen roll, it came up nice and clean with no metal bits.
Will do the draining and see what's in there before proceeding.

cheers

V.

 

[vas]

Re: port gearbox works only on reverse

notice noone has replied on this simple Q, so posting it here alone to attract your attention and hopefully have an answer

Anyone able to confirm that 600h is normal for a set of disks?
To me it seems early.

cheers

V.

 

[kashurst]

Re: port gearbox works only on reverse

600 hours is not much. If the clutch pack has failed it may well be caused by the boat either hitting something or getting a big rope around the prop and putting a big shock load into the gear box at some point in the distant past. /Have a good look at the drive plate too whilst its all in bits - that may give some clue.

 

[rafiki_]

Re: port gearbox works only on reverse

Vas, I would be very surprised if the plates were lifed for only 600 hrs, I would expect 2000 or 3000. I'm not a transmissions specialist, so this is not a factual answer, but 600 just sounds stingy for heavy duty bits and pieces.

 

[vas]

Re: port gearbox works only on reverse

thanks guys,

that's what I wanted to hear all day
I'll check the easy bits first, see if the diverter is working, if not, i'll remove the oil and check for debris, then I'll remove and see who'll repair it.
28th is a national holiday down here, so may have a go at checking it.

cheers

V.

 

[rbcoomer]

Re: port gearbox works only on reverse

Hi Vas,

Sorry to hear you have gremlins so soon after launch, although I guess a few teething issues were to be expected...

A bit of a long shot, but presumably you are certain it's gearbox not prop or shaft - as in prop somehow worked loose etc? I'm sure you'll have checked that the shaft wasn't turning, but would hate to think of all the work pulling the gearbox out only to find it was something else! I'm assuming this won't be the case as I'd guess prop would be pushing against shaft in forward and if loose, more likely therefore to slip in reverse? Just in case I'm missing something however, thought it was worth a mention! Good luck for a quick and easy/cheap fix - if such a thing exists with boats...

 

[vas]

Re: port gearbox works only on reverse

Hi Vas,

Sorry to hear you have gremlins so soon after launch, although I guess a few teething issues were to be expected...

A bit of a long shot, but presumably you are certain it's gearbox not prop or shaft - as in prop somehow worked loose etc? I'm sure you'll have checked that the shaft wasn't turning, but would hate to think of all the work pulling the gearbox out only to find it was something else! I'm assuming this won't be the case as I'd guess prop would be pushing against shaft in forward and if loose, more likely therefore to slip in reverse? Just in case I'm missing something however, thought it was worth a mention! Good luck for a quick and easy/cheap fix - if such a thing exists with boats...

better having gremlins now in Nov with temps dropping to 20C rather than next July

prop is bolted onto the box solidly through a flange with 4XM10 bolts (iirc)
was down when colleague was moving the controls and I could see shaft rotating albeit v.slowly (like 1/3 the speed of the stbrd engine on fwd.
TBH, wasn't down checking the shafts when reversing later on, but it does bite as well as the stbrd in reverse, so pretty sure reverse works just fine.

Haven't removed the prop on either side, but I understand it's not a simple task; involving heating, massive pullers lots of swearing and heavy hammers. Cannot imagine shaft slipping against prop tbh.

However, I guess there could be a far fetched thought of something wrapped around the axle/p-bracket area that doesn't let the shaft rotate fwd but loosens up on reverse, but I recon it's too far fetched and doesn't relate to actual facts: Was on the plane on clean 20m deep water with no debris around when I lost power and engine revved up, so definitely shaft/prop combo rotated less than it should compared to engine revs == something's wrong inside the box.

we shall see

V.

 

[rbcoomer]

Re: port gearbox works only on reverse

better having gremlins now in Nov with temps dropping to 20C rather than next July

prop is bolted onto the box solidly through a flange with 4XM10 bolts (iirc)
was down when colleague was moving the controls and I could see shaft rotating albeit v.slowly (like 1/3 the speed of the stbrd engine on fwd.
TBH, wasn't down checking the shafts when reversing later on, but it does bite as well as the stbrd in reverse, so pretty sure reverse works just fine.

Haven't removed the prop on either side, but I understand it's not a simple task; involving heating, massive pullers lots of swearing and heavy hammers. Cannot imagine shaft slipping against prop tbh.

However, I guess there could be a far fetched thought of something wrapped around the axle/p-bracket area that doesn't let the shaft rotate fwd but loosens up on reverse, but I recon it's too far fetched and doesn't relate to actual facts: Was on the plane on clean 20m deep water with no debris around when I lost power and engine revved up, so definitely shaft/prop combo rotated less than it should compared to engine revs == something's wrong inside the box.

we shall see

V.

Yes, agree it does sound like it's inside the gearbox. Something entangled seems unlikely as surely wouldn't explain rise in engine revs - rather the engine would be laboured and dropping rpm? I'm not that familiar with fitting of shaft props and it did seem unlikely, but would have felt guilty if I said nothing and it later transpired to not be gearbox at all! :ambivalence:

20 degrees? That IS summer for some of us you know!

 

[rafiki_]

Re: port gearbox works only on reverse

So it was working ok for a while? Then for no reason stopped? No big bangs, crashes, oil leaks? While we always suspect the worst, usually this sort of failure is most likely to be something quite simple, if you can work it out. Are you sure about the controls, cables etc?

 

[vas]

Re: port gearbox works only on reverse

20 degrees? That IS summer for some of us you know!

you should know by now that I really like teasing you lot up north It did actually drop to under 20 on Sat and Sun night, but it's up again should be 22C midday today.
Similarly to JFM (who's paid by the SOF tourist board), I'm getting my monthly allowance from the Greek tourist board

So it was working ok for a while? Then for no reason stopped? No big bangs, crashes, oil leaks? While we always suspect the worst, usually this sort of failure is most likely to be something quite simple, if you can work it out. Are you sure about the controls, cables etc?

yes P.,

no noise, no bang, no oil leak, nothing fancy looking AND reverse working just fine.
Cables all fine, turning the right degrees the lever that actuates the oil diverter valve (compared to the stbrd box next to it)

New idea (nasty one though!) that just had. Port engine is the one that I dismantled all the heat exchangers cleaned them carefully replaced all o-rings and refitted. Cannot imagine that there's any sea water leaking in there damaging the lot, but in that case the liquid level would've risen considerably. It's spot on the MAX mark as is the stbrd box, so hopefully nothing like that has happened. Mind i've done 90odd nm since getting back in the water two months ago, so i'd expect to have a seized box much earlier. Coming to think of it, with 300psi, all box oil would have been on the sea the first 5mins of operating (unless it goes through the cooler at a different pace which I very much doubt)

cheers

V.

 

[vas]

Re: port gearbox works only on reverse

seems that we have some really lovely days, no wind, sunshine and warm enough for a tshirt, so had a go this morning with various things on MiToS, sorted some water leaks and then went down to check the gbox.
Undid the cables on both boxes to feel the way they work.
Started both engines on idle and just turned the lever on both boxes.
Stbrd works fine in both fwd and reverse. As soon as you turn the lever axle start turning
Port box works as the stbrd ONLY on reverse. On forward, does bugger all.
Lifting the idle from 650 to 1000 it sort of v.slowly starts rotating the axle

Now,

Before doing that i removed the oil filters on both of them to check
Stbrd was perfectly clean, no debris.
Port was clean except for some ground metal, very little in quantity, on kitchen roll was about three needle heads in size.
Debris was NOT bronze/brass whatever yellowish thing. It was iron of some sort that was attracted by magnet.

Following this, I removed the diverter axle, an axle with two sets of opposing holes where the lever is mounted. Looked clean, couldn't do much with it tbh, looked at it a bit more and back in it went...
At the bottom of this axle was a valve, I could blow through it (with difficulty) but couldn't see the hole through it, guess that's ok.

Tried again, same behaviour, so not much achieved.

HOWEVER, I noticed that when I was engaging reverse on the port box while holding the oil to cooler pipes, you could feel a rush of pressurised thing through them. On idle, when turning the lever to fwd, you felt bugger all. At 1500rpm you sort of started feeling something (and the axle would turn a bit...)

Plan for tomorrow is to get there and try to remove the diverter valve assembly altogether. Before that, I may remove the stbrd gbox diverter axle and drop it in the port one and see what happens.

Any other ideas based on my latest findings?
found two guys that can tackle gboxes here, see how it goes and then it's off to them.

Still curious why it would fail with 600h (if it turns out it's the fwd disk set)

cheers

V.