Trolling Valves

[solanderi]

Can anyone give the Cliff's Notes version of Everything you ever wanted to know about trolling valves and were not afraid to ask ?

I have a 1985 45C w/ 6V92s and Allison gears and I can appreciate being able to attain ultra slow trolling speeds for live baiting, kite fishing, wreck fishing etc... What are my options ?

Merry Christmas and Happy New Year !

Greg

 

[yachtsmanbill]

NONE. I believe ALLISONS cant be fitted with trolling valves. If you want to replace with twin disc, I may be interested in the allisons tho. Whats the number? MH20s?? ws

 

[solanderi]

Allison MH 15 1.5 : 1.0

I am not ready to start horse trading yet because the engine and transmission are otherwise solid, I am just in fact finding mode at this point. Are Twin Discs the only other transmission w/ trolling valves ?

Is there anything that I would be giving up by changing out my Allisons for Twin discs ? Is there a better option than Twin Disc. How about maintenance, reliability etc between Allison and others ? Thank you.

 

[Genesis]

You cannot fit Allisons with trolling valves - they are a planetary gearset and due to their internal design it won't work.

If you really want them (e.g. you need to be able to run very slow for trolling purposes, etc) then your only option is to swap to a different gear such as a TwinDisc.

 

[solanderi]

Genesis,

Am I giving up anything by trading the Allisons out ? This would be a pretty big job, right ? Also, did Hatteras offer the 692s w/ Twin Disc or other trannies with trolling valves....if so which ones ? Thank you.

 

[Boss Lady]

The twin discs are the better gears. I switched my Allisons for twin discs. The Allisons are good gears for the lower HP applications. If you start your search now you can probably get a good deal on the twin discs and have your allisons sold, then find all the options you want to add, like trolling valves before you take out the allisons. Yacthsman Bill has been looking for some Allisons.

 

[SKYCHENEY]

There are some others on this site that have 6v92's with Twin Disc trans. Fanfare is one, I believe. One other good thing about switching is that the Twin Disc are lighter than the Allisons. And, as stated before, there is still a market for a good working set of Allisons. If you wait until they need rebuild, they will be worth zero.

 

[(Nobody You Know)]

Can you troll on one engine??? (I don't deep sea fish, just a guess).

 

[Boss Lady]

Yes you can, but on some gears you have to have the un-powered shaft locked down due to lack of oiling to keep the shaft from free wheeling.

 

[jim rosenthal]

Try looking at Tonan marine gears in Boats&Harbors, also, they make competitive units to TD. There is probably also a ZF marine gear that will fit, and they can use trolling valves as well. I think in order to use trolling valves, you have to be able to bypass some of the oil circulating through the unit to reduce the amount of power that goes through the gear. Note that speeding up while the trolling valve is engaged is highly likely to damage the gear.

 

[egaito]

Misty (Twin Disc) has trolling valves. They slow the boat down significantly, but have some operating parameters that have to be observed, i.e. engine speed has to stay below 1000 RPM. For some reason, mine don't work evenly either....I have to crank in a good bit of rudder to keep the boat going straight when both are engaged.

Newer Twin Discs have a nice feature for high strung boats, allowing the valves to be used during docking maneuvers, which is nice when you have a lot of "bite" at idle, as Misty does. I have to tell folks to "hang on" when I put her in gear.

Depending on your configuration, there are several things that come to mind to consider, some of which have been mentioned:

If you troll on one engine, make sure your tranny (for the other) is rated to freewheel, or be sure to lock the opposite shaft. There are several ways to do this, my favorite being the wooden clamp (was that you Maynard?).

Some trannies can freewheel (mine can), but if you have a water cooled shaft seal, you have to keep the motor running to cool it (oops!). You can also put a "T" between them so one engine cools both seals....a project on my list due to the previously mentioned "oops".

I've seen drouges (spelling) that can be deployed to slow boats down, kind of like reverse sea anchors. Not sure if something like that would work for you.

 

[GaryNW]

I believe that trolling-valve equiped xmissions may require additional cooling considerations. My old firm built a 58' seiner with a TD 4.5:1 reduction behind a 12v71. The engine supplier, in Seattle, insisted on an auxilliary heat exchanger with it's own pump for the gear. The owner hated this arangement (engine was keel cooled), didn't believe the aux cooler was necessary and fought the supplier for six months over the issue. He finally just plumbed it in to the keel cooler even after they said "no warranty". I don't know if he had any problems.
Gary