QSB6.7 trolling

[steve lehman]

I have 2013 QSB 6.7’s. I’d like to know if slow trolling in and out of gear is OK.
Also, what is involved with installing trolling valves.
Thanks.

Topic

[Justin Riege]

Sorry for the delay, I was out of town and off the grid for the holiday.

The kit doesn’t specifically come with instructions but we can do our best to walk you through it remotely.

I would say you need to be reasonably mechanical, not that its exceedingly hard to install a trolling valve, but if you cross thread the sending unit, or strip a bolt that holds the assembly to the gear, or anything like that it could be a costly or at least a time consuming mistake.

That said, its your call to make. If you take your time, are careful and mechanical enough to know the feel of threads going in right, and you take the time to use a torque wrench or you at least have enough skills that you can “feel” an appropriate amount of torque. It’s totally doable.

Just like anything else, its easy when you know how.

[steve lehman]

One more question. Do installation instructions come with the kit?
How mechanically inclined do you have to be to install the electronic trolling valve ?
Thanks.

[steve lehman]

OK thanks Justin.

[Justin Riege]

okay steve, here you go…

First an article on trolling valves by Tony
https://www.sbmar.com/articles/marine-transmission-trolling-valve/

Here is the trolling valve
https://www.sbmar.com/product/zf-marine-85a-85iv-atf-series-shift-valve/?attribute_valve-style=12V+Electric+Shift+with+Troll

Here is the gear pressure sending unit tony recommends
https://www.sbmar.com/product/cummins-vdo-gear-oil-pressure-sending-unit-0-400-psi/?attribute_configuration=Single+Station

And here is the gauge
https://www.sbmar.com/product/vdo-gear-pressure-gauge/

You’ll need to do a bit of wiring, for the gauge and the control.

[steve lehman]

Justin, the ZF’s are 85A, 2.5 ratio, 20168008 and 809.
Can you recommend a trolling valve kit? Trust you know these are electronic. Also, shift lever has a slow troll mode on it.
Thanks.

[Rob Schepis]

Justin Riege wrote:

I’d like to hear if anyone has seen these transmissions wear out from excessive shifting. Rob??

I have not. Important to be mindful of keeping an eye on the shift lever for full travel and lube. And frequent checking of the gear oil to be sure it is as it should be….

[Justin Riege]

When you think about it, all the trolling valve does is allow a bit of controlled slippage. When shifting in and out of gear, basically your are transitioning from fully open very low friction, through a range of slippage as the inertia of the shaft, prop, and output side of the gear is overcome and accelerated to synchronicity, to fully engaged over a short span of time. Maybe about a second? Shifting in and out of gear is what a boat gear is designed to do. I think about when we wakeboard or ski on my ski boat, borg-warner velvet drive. Picking up a skier, bring them the rope, slack up, reverse for a sec while they adjust, slack up hit it, do it all over. I could shift in and out of gear 200 times for a hour or two of skiing. Never gave it a second thought. Is it theoretically more wear on the gear with every shift, sure, but my guess is you choose to go to the trolling valve more for comfort, consistency, enjoy-ability than fear of excessive wear.

A lot of high HP boats have to shift in and out to stay withing no wake speed. We did it on a sea trial with Tony just the other day.

I’d like to hear if anyone has seen these transmissions wear out from excessive shifting. Rob??

My guess is you will get a lot of qualitative advice, like “well as long as it isn’t excessive it will be okay” but it might be hard to find anything quantitative… No one is going to say keep it under “68.2 shifts per hour and you are good.” So the question is what is excessive?

[Roger Franklin Williams]

Frequent Shifting

Have 1998, 6BTA’s with ZF transmissions. Docked 1 mile off Ohio River up a Creek and we encounter considerable small and large drift at various times of year. To prevent hull and prop damage requires considerable shifting in and out of gear and reverse at idle RPM’s. After reading this post curious if this shifting pattern is causing any excessive wear be on normal shifting wear?

[steve lehman]

Thanks for the reply. I’ll get my ZF info for you.
I’ll be in and out of gear every 10 seconds and I alternate engines.

[Justin Riege]

How much trolling do you plan on doing?

Bumping in and out of gear a bit probably won’t hurt anything if it isn’t excessive, but its not the most pleasant way to go about things.

Which exact gear do you have?

We could easily recommend the proper trolling valves for mechanical and electronic shift gears, but we’d need to know what exact gear you have, and what type of control system you have in place so we can tell you what you need.

[Author]

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