Hard to shift DP-S volvo

Hey guys ,posted this problem last aug. with no reply sooo,I will try again with all the #s needed. (I hope!) Working on my 1997 Volvo Duoprop mod (DP-S p.n. 3868164, s.n.4112034408 starboard drive)Has twin outdrives pushed by 5.7 efi chevys.Problem is warm engines,idling at 650 rpm out o gear,600 rpm in gear,It takes YANK-YANK-YANK to get out of gear(either side,They are the same)!Makes for major problems in tight quarters!The past owner had the same complaint(I found out after she was launched in the spring last year). This Larson Cabrio 31 got new shift cables,gimbal bears,boots and new gear oil ( merc.hi-perf) Don't want another summer of docking HELL! She is hauled needs to be fixed,ANY suggestions?Thanks WALDO

Re: Hard to shift DP-S volvo

The only 2 things I can help you with are

1) Change the shift cables but it sounds like you already did this.
2) Make sure the gear oil isn't overfilled as this will cause that problem.

You could disconnect the cables at the drive and operate the control just to make sure that it still isn't a shift cable issue or the control itself for that matter..

Re: Hard to shift DP-S volvo

You mention that both drives are acting the same!
Short of what has already been suggested, I'd verify your idle RPM.
A sliding sleeve/gear cup (cone clutch) can act much like a dog clutch system w/out an interrupt, if idle speeds are too high to allow for dis-engagement!
(with thrust, the more they wish to remain engaged)

It has to do with the amount of thrust that a propeller places on the gear engagement while the boat is at slower-than-prop-thrust hull speed.

Question: if you are out in the water away from the dock, and moving forward at let's say 1,200 rpm, and if you were to back off on the throttle for a neutral shift, is the shift easy?
If so, there is part of your answer!
If not, back to the drawing board!

Re: Hard to shift DP-S volvo

Thanks 4 the reply.The lube level is dead on, and about trying to go to neutral while still movin forward and shiftin better,nada.I was leaning toward lube type cause I don't know the viscosity/additive package in the merc H.P. vs. Volvo syn.lube. If I pull the controls back with steady pressure,not yank,it will EVENTUALLY come out of gear,knott good in tight quarters.About the cables,when I have the cable disconnected from the drive,the shift shoe moves way in and out when shifting,..in-in drive,out-neutral,in-in reverse.(Worn shoe,eccentric piston,upon inspection they LOOK fine?) Am hoping someones grey matter has something stored in there related to this problem! Thanks,WALDO (P.S.idles at 650 warm,outta gear. Damn TBI EFI,cannot lower the idle speed.)

Re: Hard to shift DP-S volvo

myself I would check the shim adjustment on the shift mechanisim on the drives.
if its loose it wont wish to come out of gear.
lube level wont affect coming out just going in.
650 idle is perfect, why lower it?
simply fix it.
the cone has an eccentric machined into it, the shift housing has ramps that can wear but typically its impropper shift shimming.

Re: Hard to shift DP-S volvo

I/O WALDO said:

............
(1) I was leaning toward lube type cause I don't know the viscosity/additive package in the merc H.P. vs. Volvo syn. lube. If I pull the controls back with steady pressure, not yank, it will EVENTUALLY come out of gear, knott good in tight quarters.

(2) About the cables, when I have the cable disconnected from the drive, the shift shoe moves way in and out when shifting,..in-in drive,out-neutral,in-in reverse. (Worn shoe,eccentric piston,upon inspection they LOOK fine?)

Click to expand...

(1) It is possible that incorrect oil may be contributing to this? Oil that is allowing or causing excessive sleeve/cup contact? Volvo recommends their oil for these.


(2) The eccentric piston will move In/Out on these by design. There is no adjustment to this piston.... only shims aft of the shoe, of which are set at the factory.

Rodbolt, good points!
And you are dead-on regarding the eccentically machined shift shoe channel. The purpose is to cause a mild hammering effect while the shoe is attempting to pull the sliding sleeve away from it's mating gear cup.

Odd that both drives are acting the same. It may be an indicator of something other than a random malfunction issue. This leads me to # 1.... oil type... possibly!

Re: Hard to shift DP-S volvo

Thanks ,The port and starboard drives have only 425 and 455 hrs. respectivly so one would think with yearly lube changes on 13 year old drives that the wear would be mimimal.I found the procedure on pg 3-34 of the repair man., how to "shim the the shift actuator".I will follow the shimming procedure and fill them with Volvo Syn.lube,get a rabbits foot and put-er in the rivah! WILL let yall know the outcome. ( I miss my B1s!) WALDO

Re: Hard to shift DP-S volvo

Can anyone research what the Volvo bulletin P-44-1-7 is about. Is pertains to my shift question I think.(My pooter won't open it) WALDO and 'preshate it!

Re: Hard to shift DP-S volvo

I/O Waldo, did you ever figures this one out? I have a 1997 Larson 310 with 5.7 and duoprops in which both are hard shifting in and out of gear (more so out of gear into neutral and into gear but both are very stiff).