Marine Gearbox TWIN DISC MG5061A - No Forward

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# Description PartNo. Qty Price (EUR) 1 Reversing gear 1 Out of production RATIO -2.0:1 1 Components not spec. Out of production 2 Gasket 862623 1 24,53 3 Stud 953486 12 1,59 4 Spring washer 942336 12 0,48 5 Hexagon nut 955827 12 0,49 6 Hexagon screw 940114 8 0,73 7 Spring washer 942336 8 0,48 8 Bracket 864242 1 110,05 9 Hexagon screw 955570 2 Out of production 10 Spacer sleeve 830672 2 19,61 11 Cross recessed screw 956079 2 Out of production Replaced by: Screw 969408 1 0,49 Screw 969408 1 0,49 12 Bracket 21471054 1 2,53 For control cable 333, 33C. 12 Cable clamp 6853782 1 3,41 For control cable 443, 43C. 13 Washer 819068 1 4,73 14 Lock nut 963104 2 0,48 15 Cube 853217 1 23,69 16 Washer 940191 1 0,69 17 Split pin 17253 1 1,44 18 Control Out of production SEE GROUP 27 19 CONTROL CABLE Out of production SEE GROUP 27 20 Companion flange 842106 1 1 043,78 21 Hexagon screw 955739 6 6,25 22 Spring washer 941912 6 0,49 23 Lock nut 950378 6 Out of production Replaced by: Lock nut 8123368 1 1,24 24 Actuator solenoid 3825653 1 675,60 12V 24 Control solenoid kit 3825654 1 675,60 24V 25 Cable kit 873827 1 219,03 26 Cable tie 948211 2 0,49 27 Engine suspension 2 Out of production SEE GROUP 21

Volvo Penta exploded view / schematic / Reverse Gear MG 5061A ...

Have you searched Google?

Thank you so much, This is the most detailed installation drawing received or found. And probably thanks to Volvo and You of course. Google tells me a lot about the dealerships and companies, users's manual are to download, but tell me nothing. One site shows a demo cut-open picture, some publications from TWIN DISC, but nothing essentially useful. I know about everything about their whereabouts, stocks ratings, employment, which I think can change drastically if they abandon their customers like me. That model transmission was built in Belgium and there they also didn't answer the questions. As a client I feel very disappointed about the service. There is a dealer, claiming to have 24 hour service for parts to the Caribbean, but how can I know what to order if I have no exploded view? Taking out the gearbox is a very big job. Sending it to the US also, plus customs duties two ways. I can do the job myself if I have some documentation. I will start calling some dealerships in the USA. I didn't dismantle anything yet, because I want to make sure that I can replace the parts while the transmission is in the boat. Sailing the boat to the US in reverse will take me 5 days and doesn't look tempting at all.

I had exactly the same thing happen to me thirty years ago... We dogged it for two day trying everything in the world but, we had a twin engine so we ran back to ft lauderdale on one and got the other one fixed.. If I had to do it today and I was there with a single I would pull the unit by disconnecting the drive unit out the back. Use the back of the transmission as a lifting point, disconnect the engine mounting bolts from the transmission and pick it up high enough to put a doubled 2x4 or a 4x4 or a hunk of steel from stringer to stringer. Then you have two options call ahead and have them send you a rebuilt one.. or if it is a single you can probably find a used one.. or convert it to something more friendly to the us.. last but, not least send that one to a rebuilder in the us by buying it a seat on the local puddle jumper then sit back and wait unless you want to go with it.. I would never advise trying to fix it in the carribean and in the boat that is a recipe for disaster or spending the summer there awaiting all kinds of parts and repair items. This comes from someone that has been there and has a t-shirt for it.. GOOD LUCK.. wish I was there to help you..

In the Caribbean you need to fix everything with nothing. I once had to put bananas in the rear gearbox of my truck in Africa, and drove another 270 miles with it. And the sisters in Kinshasa were happy to buy it from us. They used the bananas (and the truck)for 3 more years. I can always order spare parts in the US, if I could know what to order. Twin disc seems to organize service their way with no DIY mercy. And are transmission such a grey zone for boaters there? I need to depend on getting a lay out and parts list. I hope one of the dealers will help. I still have room.

Check disc transmeter arm,could be reversed install during assembled that why oil get burnt.Gear box work related by radias ratio and rotation.Transmeter arm is to change the drive motion direction.

It has been working until I noticed slip at higher power, only in forward. Typical disc or clutch defect. Arm is ok. The gearbox still works at pulse accelerations for seconds. Does anyone know how to reach or where the couplers are positioned? There are 2 one forward and one reverse I guess. Are the ring plates bronze, steel or different stuff? Only one engine.

Operators Manuel here no internal pictures, sadly.

www.twindisc.com/Downloads/Manuals/Operators_Manual.pdf

This could be helpful

http://transmissionmarine.com/Forums/main.cfm?CFApp=72&SR=1&Forum_ID=181&un=1268625830830

A forum that has quite some posts about twin disc. No schematics or parts plans found.

i'm sorry to tell you this,but if your clutch pack is burnt you have to pull it out of the boat and split it in two to change your clutchs,no other way to replace them.

Thank you all for your input. Much appreciated.

That will be several possible forward clutch not working

1- clutch plates burnt , internally there have both sintered and steel combination plates, operation in hash engagement or to sudden crush stop, it keep repeating for a long period, clutch surface slowly worn out and it will slip on the moment you tried to engage clutches ( either in forward or reverse way ). This is most common problems

2- Piston surface scoring mark, oil pressure pushing through piston to clutches.

3- Forward pinion crack or pitted .

hope it will helpful

Almost the end:

After having a US gear box repair shop made a quote for $3,900.00, we shipped it and got it back, bot not without paying an extra $2,500.00 (payable in advance or no repair) and 2 months later than promised. The sintered discs were burnt, replaced and hopefully also the bearings ( are on the bill).

Now the cause:

Algae and mineral deposits in the heat exchanger/oil cooler AND no temperature gauge or alarm for it. Black oil and metal pieces in the oil gave us a direction to think. Next week, we'll put it back to work. Thanks a lot for all your input. It helped.