Repowering with DTS and keeping existing manual shift transmissions

bfernald0

Well-Known Member
May 18, 2020
410
Marina del Rey, California
Boat Info
340 Sundancer 2001
Engines
8.2L Mercruiser ECT Horizons
Writing to share a little known fact, that even Mercury Marine appears to be unaware of. I purchased a never used and well maintained 2001 Sea Ray 340 Sundancer with the 7.4 MPI V-drive set up, from the original owner's family (he had recently past). The boat had 180 hours on it. While immaculate (the plastic packing was still in the microwave and the cockpit carpet in the original plastic bag from the factory), the engines were rusted out from the inside (you could eat off the exterior of both motors). While we had hoped to the contrary, we suspected we'd be into the boat for new engines.

Anyway, purchased two new Mercury 8.2l ECT engines, which these days are only DTS. Thus, Mercury told us you had to purchase the new transmissions as well, that had the DTS shift capability. NOT SO. The ZF/Hurth v-drive transmissions have a shifting block on the back of the transmission. On the existing manual set up, the shift cables hook onto that shift block. On a DTS transmission (you can only get the DTS transmissions today new) that shift block has been replaced with an electronically actuated version. There are a number of these 'used' electronic shift blocks on the market because, when someone with a manual shift boat has to purchase a new transmission (they only come now with the electronic shift), the electronic shift block is swapped with the existing manual shift block on the bad transmission.

Long story short, we installed the new engines with the existing transmissions, located two take off electronic shift blocks at a marine transmission shop in Ft. Lauderdale and were good to go, with one exception. To complete the install, two 500 PSI transducers (about 150 a pop) must be purchased from Mercury, that screw into the shift block and connect to the new DTS harness. Part No. 865664. See the part diagram attached.

She's running full DTS with the new engines and existing, formerly manual shift
6-4-2020 7-36-18 PM.png
transmissions.
 
Wow, that sounds like an amazing boat, especially with brand new engines. Great piece of information.
 
I was told I need to replace that part (Mercury Part No. 865664). Were you able to know what it does?
 
I was told I need to replace that part (Mercury Part No. 865664). Were you able to know what it does?

They are pressure transducers. What they actually do in terms of the dts system I don't know. Are you having some sort of shifting issue?
 
They are pressure transducers. What they actually do in terms of the dts system I don't know. Are you having some sort of shifting issue?

My port engine cannot go more than 2000rpm when in gear.
 
Wow, I would have no idea what the pressure transducer has to do with that. Interesting.

I don’t either. But that’s the instructions that the Mercruiser dealership tech got from Mercruiser tech support. That transducer is found only in the transmission of boats with DTS. They think my DTS is failing and it puts the engine in guardian mode. The DTS failure is caused by one of the transducers not giving the correct signal. Other than that, I have no idea how it works.
 

Forum statistics

Threads
113,163
Messages
1,427,599
Members
61,072
Latest member
BoatUtah12
Back
Top