Digital Throttle/Shift (DTS) Shift Adjustment ???

tpenfield

Moderator
Staff member
Joined
Jul 18, 2011
Messages
18,040
Greetings,

In follow up to my Axius Joystick Calibration thread (which actually seems fine), I have discovered that the port outdrive has 'delayed' shifting and does not go into gear at idle, but rather takes a but of throttle (1,000 RPM +/-) to engage.

My first order of business is to check the shift linkage/cable adjustment, but I am not sure about checking the adjustment, since most/all published procedures pertain to the manual shifting mechanism.

Is there a special procedure/tools for the DTS ? The shifting is done by an electric actuator rather than cables. I assume the lower part of the linkages (i.e. lower cable) is the same.

If the adjustment proves to be fine, my next step may be to check the cone clutch for glazing. I did the 'poor mans' fix on my previous Bravo drives a couple of years ago.

Not sure if there is a service manual for this (DTS) or not. Any help on this is appreciated. (y)
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
42,056
Agree not much out there, but very few parts also that does the shifting. I might try swapping the shift actuators to see if it goes with it. If no change, then it's the lower cable or the drive
 

dubs283

Vice Admiral
Joined
Jul 27, 2005
Messages
5,322
check the cone clutch for glazing.
First thing I'd do is verify the throw of ghe actuator. Don't have a spec but you have a good shifting system, measure that one and compare. Next I'd verify lower shif cable adjustment, can be done with the plastic tool on the shift plate. If all is good then you're looking at a drive pull and inspection. At that point it'd be in you're interest to just change the lower cable, it's a merc after all

Drive off, drain, pressure test, remove the rear cap and inspect the linkage too. In depth analysis will require u joint assembly removal, driven gear/ drive shaft removal, disassembly and inspection of the clutch/races

Best guess at this point is if it's not the lower cable it's the clutch, especially if your experiencing a slow shift into only one gear, not both
 

tpenfield

Moderator
Staff member
Joined
Jul 18, 2011
Messages
18,040
Thanks guys. I suppose I need to buy the bravo shift tool (gauge thingy). I'll see if the actuator 'throw' is the same for both engines.

The slow shift is only in forward on the port drive, which suggest it being the clutch rather than the adjustment.

BTDT on my previous boat.
.
img_0652-jpg.338164

.
These engines/outdrives have 295 hours, so it is a bit early for clutch problems.
 

tpenfield

Moderator
Staff member
Joined
Jul 18, 2011
Messages
18,040
I'm also wondering about the method for checking the actuator movement. Not sure if it will work with just the ignition on, but engines not running.

. . . or . . .

Shift with the engines running and turn the engines off while in gear.

Of course, this all explains while I have been such a goof maneuvering around the dock lately.
 

dubs283

Vice Admiral
Joined
Jul 27, 2005
Messages
5,322
Def early for clutch issues. But if adjustment is off or other issues exist that can be cause for failure

FYI clutch pictured isn't glazed, just shiny. Glazing is when the high point on the face gets "smashed" from lack of maintenance, poor lube quality, misadjustment or abuse. Abuse being ubiquitous considering load, environment and general fun
 

tpenfield

Moderator
Staff member
Joined
Jul 18, 2011
Messages
18,040
Ted, looking at parts break down the DTS doesn't use the same shift plate. What does your manual show for setting?

https://www.mercruiserparts.com/bam/subassembly/31758/15323/370
I don't have the DTS manual and my engine manual really does not show much as far as shifting.

We were out in the boat and I paid additional attention to the port engine shifting. It seems to go 'softly' into gear with slight boat movement, but the thrust does not increase with corresponding RPM increases, until 'clunk' the drive fully engages, which is around 1,000 rpm.

I've been docking using the movements that the boat will make which are the yaw to port and crab to port.
 
Last edited:

tpenfield

Moderator
Staff member
Joined
Jul 18, 2011
Messages
18,040
Ted, looking at parts break down the DTS doesn't use the same shift plate. What does your manual show for setting?

https://www.mercruiserparts.com/bam/subassembly/31758/15323/370
Not much in the manual . . . I did come across something that said there was no adjustment (just can't remember exactly where). I think my next steps are to see if the actuator throw is the same for both engines and then if that all checks out maybe pull the boat to check the lower cable, etc.

Is there a newer Bravo Service Manual for the new style outdrives? I have the older version. Not sure how much has changed.
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
42,056
Don't know of one later then 28.
Might be a later install manual or separate Digital manual, don't know

Looking at Mercury parts (only place to see your motors) it shows the shift bracket better and there is not any tool that could be used so far as I can see other then with mechanical shift
 

tpenfield

Moderator
Staff member
Joined
Jul 18, 2011
Messages
18,040
Yes, it seems that the more recent versions of Mercury/Mercruiser stuff is not as well documented (yet) vs. the 20 year old stuff. I might check the Merc website to see if there is some newer versions (although I'd have to pay for them).
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
42,056
Agree, if you go to Mercury site, it shows the same pic.
Can also find the Axis components
 

tpenfield

Moderator
Staff member
Joined
Jul 18, 2011
Messages
18,040
Quick Update . . .

It has been difficult to find some time to do some additional tests on the
Axius Joystick the shifting. I did find some time today . . .

I 'undressed' the engines so I could see the shift actuators in action. Both engines/actuators appear to have identical 'throws' of the actuators. So, I can move onto the next set of possibilities.

If I use the joystick with a bit more authority, the port engine does engage into forward, and I was able to spin the boat in either direction. I'll just have to be a bit more deliberate around the dock.

I probably will take a look at the clutch in both outdrives over the winter, since inspecting them and potentially 'fixing' them is not a huge deal.
 

dubs283

Vice Admiral
Joined
Jul 27, 2005
Messages
5,322
I probably will take a look at the clutch in both outdrives over the winter, since inspecting them and potentially 'fixing' them is not a huge deal.
This would be my next move, along with checking/setting lower shift cable adjustment and linkage inspection
 

tpenfield

Moderator
Staff member
Joined
Jul 18, 2011
Messages
18,040
As I'm gaining familiarity with the joystick through use and testing, I am seeing that not only is there shifting consideration, but also engine RPM.

I was using the joystick yesterday to spin the boat around and noticed that one engine was going faster than the other. My thoughts were due to prop efficiency of being in forward vs. reverse (forward being more efficient, I'm assuming)

So, I'll keep this in mind as I continue to use the joystick to see if anything obvious reveals itself.
 
Top