oldmanofthehills
Well-Known Member
I think the most important thing is to use a more reliable clutch system, such as used for many many years by numerous other marine gearbox manufacturers
Technodrive TMC40M clutch slipping?
- Thread starter PaulGS
- Start date
bluerm166
Well-Known Member
Perhaps someone who has experienced a failed TMC40 could do a questionnaire of first owners so that we can get an impression of the falure rate .
e.g. failed at x nautical miles ,y years after I bought it new,comment e.g.replaced under warranty or still running.
My TMC 40 ws running happily when we lifted out but I would like to see and contribute to a similar questionaire on Raymarine tiller pilots ,whose failure rate must be a great deal higher.
e.g. failed at x nautical miles ,y years after I bought it new,comment e.g.replaced under warranty or still running.
My TMC 40 ws running happily when we lifted out but I would like to see and contribute to a similar questionaire on Raymarine tiller pilots ,whose failure rate must be a great deal higher.
Boater Sam
Well-Known Member
I would pension it off and replace with a PRM95 which will be infinitely reliable. Almost a straight swap, just a slight drop height difference.
fishermantwo
Well-Known Member
The gear ratios are different.
From my notes, The ATF should meet Allison C-3 or Caterpillar TO-2 specifications or Dexron 2 if available. Dexron 3 and above have too much in the way of additives and may foam. I can not find the manual now but I did take a photo of the adjustment procedure.
Tranona
Well-Known Member
See post#9. not quite so simple as the PRM is also a bit longer, but doable. However if the TMC is a 2.65:1 a different propeller (or repitching) may be needed, particularly if it is a feathering propeller with a different pitch forward and reverse. The TMC is 2.65 in forward and 2:1 reverse and the PRM is 2.5:1 both ways.
fishermantwo
Well-Known Member
Talk about not reading my own posts! The ATF specifications are in the bottom part of the first photo from the manual above. Basically what the manufacturer is saying is modern ATF"s meant for the new generation of cars are too good for a gearbox that needs some friction.
PaulGS
Well-Known Member
Thank you for posting this. This is the procedure I intend to carry out. I'll likely change the oil too (though it looks like honey and I very much doubt that it's an issue in this instance - it's "ATF".
fishermantwo
Well-Known Member
ATF is always red. Honey coloured makes it a hydraulic oil.
mogmog2
Well-Known Member
If I could tag a question on, any idea how I can tell which TMC40 I have? And consequently whether I should be putting sae oil or ATF in? Thanks.
FWIW, mine's old (1997) and works as intended. No complaints.
FWIW, mine's old (1997) and works as intended. No complaints.
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PaulGS
Well-Known Member
The exact model number should be on the gearbox itself. As the original poster I might just add that I never got around to making any adjustment and the engine has performed flawlessly since. Probable false alarm!
mogmog2
Well-Known Member
Thanks. It seems my serial number plate has gone AWOL so I've no idea. I've emailed Beta now but not sure how soon I'll get a reply. Thanks anyway.
fishermantwo
Well-Known Member
All TMC40's use the same fluid. The only difference between them is the ratios.
mogmog2
Well-Known Member
Found thisBoatbot
New Member
So I’ve read through the threads I’ve got a Tmc 40 techno drive gearbox mated to a beats marine 14 it was put into the boat in 2002, I acquired the 22 foot Boat and proceeded to clean out all the blocked heat exchanger ecetera, the engine has been running really sweet. All gears have been working fine however when I dipped the gearbox oil it was low, I read somewhere that a little bit of engine oil wouldn’t hurt (chat gpt), anyway my fwd gear now slips and engages abruptly the reverse still works with some slippage. I then found a bottle of ATF “old” so swapped out the old for this and ran it with no improvement, I then bought dexron 3 as it states you can use that, but looks like after reading here it’s not great, I have wound in the Allan key bolt until the driveshaft locked in neutral and wound back 270’, all fluids removed look very dark and grainy, so it still slips in fwd drive and in reverse L, beta marine said clutch is £300 but best change the whole gearbox for the updated version £612 +vat as I have the old bell house gearbox, I’m on a real Tight budget and I’m thinking to lift the engine and remove the bell house take out the clutch and get the cone reconditioned which I read is possible.
This means labour for me which is free and doable as long as I can get the bolts to come off ok,
Is there any way the clutch is just filmed up?
Also what other options are there to get the clutch to work without the hassle ?
I also read that it’s bad to throw the fwd reverse lever quickly and this may be why I have shredded the friction surface ?
Can I flush the gearbox and add a non slip something
, thanks for any input
This means labour for me which is free and doable as long as I can get the bolts to come off ok,
Is there any way the clutch is just filmed up?
Also what other options are there to get the clutch to work without the hassle ?
I also read that it’s bad to throw the fwd reverse lever quickly and this may be why I have shredded the friction surface ?
Can I flush the gearbox and add a non slip something
, thanks for any inputoldmanofthehills
Well-Known Member
It uses a plate clutch similar to a car, not a sintered steel cone clutch, hence the twin disc designation
If the clutch friction material has worn away there is nothing to be done except replace the discs. Re-conditioning not possible except by adding new clutch. With bearing pullers it should be fairly easy to take gearbox apart if you are into such stuff, but I replaced the gearbox. It uses ATF like an automatic gearbox in car, and mineral oil will kill it as makes the friction plates slippy
Beta accused me of going straight to reverse and wrecking my clutch, but I never did such a thing, its just a consumer unfriendly but TMC en-richener build thing. There are other gearboxes that fit and I could have ordered my Beta 25 with such if I had known the nonsense I was going to get with TMC. Nice engine but -----
If the clutch friction material has worn away there is nothing to be done except replace the discs. Re-conditioning not possible except by adding new clutch. With bearing pullers it should be fairly easy to take gearbox apart if you are into such stuff, but I replaced the gearbox. It uses ATF like an automatic gearbox in car, and mineral oil will kill it as makes the friction plates slippy
Beta accused me of going straight to reverse and wrecking my clutch, but I never did such a thing, its just a consumer unfriendly but TMC en-richener build thing. There are other gearboxes that fit and I could have ordered my Beta 25 with such if I had known the nonsense I was going to get with TMC. Nice engine but -----
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Boatbot
New Member
thx for your reply but according to beta marine and also my research into this unit it's a bronze double cone clutch, also it has not changed since its introduction! It's a servo (hydraulic) assisted typE
fishermantwo
Well-Known Member
No. It is a Twin Disc manufactured box, but it is a cone gearbox, just check the manufacturer's diagrams. Only use mineral base oil and stick to what the manufacturer says regarding the required oil. Beta are not the manufacturer. ISO32 is the closest you will get to with modern oils. INDUS PRO HYDRAULIC 32 | Penrite Oil
Boatbot
New Member
Thx for the replies, I had mentioned that it’s a cone that has the friction materials, also it’s a shame beta has said use dexron2 or 3 I have used the 3 and it still slips, possibly more than before, I’m wondering what’s the possibility of flushing the box clean with the iso32 type oil? Would this potentially help with the slippage?
I’m thinking to do two or three oil changes to see if it helps?
Worth trying I guess as a short run on each flush would clean off any film that’s on the material,
I’m thinking to do two or three oil changes to see if it helps?
Worth trying I guess as a short run on each flush would clean off any film that’s on the material
,
alahol2
Well-Known Member
I would maybe try flushing with Paraffin, that's what I use to remove old grease from winches etc. I'm no engineer, what do proper engineers think?
Boatbot
New Member
Thx that sounds like an idea but I think flush with the iso32, rotate the propshaft by hand at least 10-20 revolutions and empty, doing this twice will probably get rid of any dexron3, I think this may work as long as all the slippage has not worn away all the material, now I know why the oil went a dark colour after a short spin 