low to no propulsion

[anikanvader]

I have a penta 275 outdrive. I replaced the upper unit recently and when i put it on the water I barly was able to get it to move. everything sounds good to me. i started it in the driveway prior to putting the prop back on and the shaft spun just fine. what could be the cause of this?

 

[sandkicker]

Start with the easy fixes.... when you replaced the upper unit did you

1) properly retain the jacket of the shift cable at thh point where it enters the upper unit.
2) follow the factory adjustment procedure for the shift linkage

Fast check... with the back cover off, observe the shift cable as it extends from its jacket.
It should fully EXPEND when in FWD and fully RETRACT when in rev...

And then there is always the ugly possibility that your "new" upper unit has "issues"... assuming that "replaced" did not really mean "reinstalled"... There is a shimming procedure you need to do if its another unit, however that is a longevity issue not a work/not work issue.

 

[anikanvader]

Everything looks to be shifting completely in forward and reverse I was told that it was a possibility the propeller hub might have spun. Does that sound accurate? I was thinking I needed a new one anyways. I have only had it on the water 1 time prior. That's when I heard the grinding. Took it to a mechanic and he told me what was wrong and so I purchased the used upper unit. Everything sounds great just dont understand why it dont take off now just puts along

 

[sandkicker]

Usually you look first to the last thing that was done when troubleshooting... That said it sounds like a spun prop hub Usually, when they fail there is some prop blade damage as well... unless you wrapped a ski tow line up in the prop.. or some other like event. get permanent marker and draw a line on the prop cone and onto the prop itself. Put boat in water, and shift tp fwd try to move boat. IF line is undisturbed you have another problem. RE grinding.... Volvos have a breakaway section in the vertical drive shaft to the lower unit...

 

[kimcrwbr1]

Are you using 10W30 engine oil in the gearbox? Are you saying it revs up just fine? What was the reason you changed the gearbox? Did you put the coupler between the verticle shafts. Maybe disconnect the link to the shift cam in the upper gearbox and shift manually possibly the shift cable /control box not shifting fully into gear?

 

[anikanvader]

I did use 10w30. The seals got chewed up in the old upper unit and messed them up lower gears were fine. i made sure the coupler was seated and joined the two. I have switched the gear box by hand.

 

[anikanvader]

I will try the drawing a line, but I am unsure of the breakaway section you mentioned. Do you have a diagram or pic of that? thanks in advance.

 

[RicardoMarine]

................

I have a penta 275 outdrive. I replaced the upper unit recently and when i put it on the water I barly was able to get it to move. everything sounds good to me. i started it in the driveway prior to putting the prop back on and the shaft spun just fine. what could be the cause of this?

1...... a transmission (upper unit) sliding sleeve that is not locking up with the gear cup.
2...... a bad prop hub, but you would have noticed that on your first outing.

Question:
When you removed and replaced the transmission, did you go through the proper re-shimming procedure?
If not, damage may occur!

Start with the easy fixes.... when you replaced the upper unit did you

1) properly retain the jacket of the shift cable at thh point where it enters the upper unit.
The shift cable enters the Intermediate housing and continues on to the gear yoke.
I as read this, the OP replaced the transmission ONLY.

2) follow the factory adjustment procedure for the shift linkage

Fast check... with the back cover off, observe the shift cable as it extends from its jacket.
It should fully EXPEND when in FWD and fully RETRACT when in rev...

And then there is always the ugly possibility that your "new" upper unit has "issues"...
Yes..... and there is no accurate means for the layman to test this while on the work bench.

Everything looks to be shifting completely in forward and reverse I was told that it was a possibility the propeller hub might have spun. Does that sound accurate?
I'm thinking that you would have noticed it on your last run.

I was thinking I needed a new one anyways. I have only had it on the water 1 time prior. That's when I heard the grinding.
Describe this "grinding" for us.
When you drained the 30W gear oil (for the transmission replacement), how did the oil look? Any metallic debris?


Took it to a mechanic and he told me what was wrong and so I purchased the used upper unit. Everything sounds great just dont understand why it dont take off now just puts along.
Is this mechanic trained in the AQ series Volvo Penta drives? In other words, does he have AQ series experience?

....................... get permanent marker and draw a line on the prop cone and onto the prop itself. Put boat in water, and shift tp fwd try to move boat. IF line is undisturbed you have another problem.
Ditto!

RE grinding.... Volvos have a breakaway section in the vertical drive shaft to the lower unit...
Although I have seen my share of sheared off vertical shafts, the "shear" feature is actually a small grove that has been cut into either the OD or the ID of the vertical shaft spline coupler.

Are you using 10W30 engine oil in the gearbox?
Good point.
The s/p drive requires 30W engine oil for gear oil.


What was the reason you changed the gearbox?
I too would like to know the answer to this question.

Did you put the coupler between the verticle shafts?
Good question, although it's unlikely that the coupler was removed for a transmission replacement.

Maybe disconnect the link to the shift cam in the upper gearbox and shift manually possibly the shift cable /control box not shifting fully into gear?
When adjusting the AQ series shift cable, begin with the throttle/shift unit in Neutral.
Disconnect the lower section of the eccentric piston's vertical linkage rod.
Have a helper make a FWD shift (this will extend the shift cable at the gear yoke).
With the cotter pin removed from the cable barrel fitting, further the shift into FWD.
Remove the cable barrel fitting from the gear yoke, and make sure that the shift cable offers a small amount of "over-travel".
Do same for a REV shift.
This will ensure that the gear yoke is making full travel in either direction.

Have the helper return the throttle/shift unit to neutral.
With the eccentric piston in neutral, re-connect the eccentric piston's vertical linkage rod (you may need to adjust the length one way or the other).

Once again, the helper will make a FWD and REV gear selection.
Make certain that the gear yoke does NOT contact the aluminum Intermediate housing during a FWD shift.

Now (once the above has been done) the only thing that would prevent gear selection would be an issue with either the shift shoe, the sliding sleeve and/or the sliding sleeve gear cup contact.

Occasionally heavy gear oil (as in GL-5 75-90W) will prevent enough friction for a good sliding sleeve/gear cup lock-up.

.

 

[RicardoMarine]

.................

I did use 10w30. The seals got chewed up in the old upper unit and messed them up lower gears were fine.
Keep in mind that the AQ series shares gear oil between the transmission (upper unit) and the lower gear unit.
In other words...... if a transmission goes bad, that oil has now gone through both the transmission and the lower unit.
Any metallic debris will have traveled through both gear units.

i made sure the coupler was seated and joined the two. I have switched the gear box by hand.

I will try the drawing a line, but I am unsure of the breakaway section you mentioned. Do you have a diagram or pic of that? thanks in advance.

The shear point is within the spline coupler.
If when you re-installed it as one piece, it is still in tact!

Here is a short vertical shaft spline coupler.
(the long coupler is used for the C and later drives that have a shorter length lower gear unit vertical shaft)

The shear point will be a grove cut into either the OD or within the ID of it.

 

[anikanvader]

I purchased the boat took it out on the water it was running good fast speed but i was hearing grinding sounds. I shut it down pulled it out and took it to a boat mechanic. He confirmed that my suspicion was correct that the upper unit was bad. I was told that I should purchase a new upper unit and he wanted to charge me $1200 to fix it. Being the hands on guy I am it was just cost effective to do the work myself and save $900. I did look at the lower unit disassembled and everything looked fine. I put the outdrive together and everything looks and sounds fine. I took it into the lake, backed out slow and docked waiting on my friend. As we pulled out I went to accelerate and it just never picked up and went. The engine would rev up like normal but no thrust. Forgive me for lack of knowledge I am by no means a mechanic but I am a bit mechanical. (Blue collar worker that looks up things I don't understand.) I did have debris in the old oil nothing made it past the screen though that I saw. Is the only way to test the hub marking by putting it in the water? Or can I do that in the driveway? The lake is an hour drive away.

 

[RicardoMarine]

............................

I purchased the boat took it out on the water it was running good fast speed but i was hearing grinding sounds. I shut it down pulled it out and took it to a boat mechanic.
Was this an experienced V/P AQ series mechanic..... or a general marine mechanic?


He confirmed that my suspicion was correct that the upper unit was bad.
Did you confirm this as you pulled it apart?


I was told that I should purchase a new upper unit and he wanted to charge me $1200 to fix it.
A new transmission (upper gear unit) would cost in upwards of $3,500 or so.
An experienced AQ series mechanic should be able to R&R a transmission in 3 hours or so.


Being the hands on guy I am it was just cost effective to do the work myself and save $900.
Did you repair the transmission, or did you find a good used one?

FYI: since all of the 275 transmissions are of the same reduction, try your best to find a used transmission from behind a 4 cylinder engine.... not from behind a V-8.

I did look at the lower unit disassembled and everything looked fine.
You pulled the prop shaft bearing carrier and examined the gears/bearings?
Did you install new prop shaft seals while you had it apart?

I put the outdrive together and everything looks and sounds fine. I took it into the lake, backed out slow and docked waiting on my friend. As we pulled out I went to accelerate and it just never picked up and went. The engine would rev up like normal but no thrust. Forgive me for lack of knowledge I am by no means a mechanic but I am a bit mechanical. (Blue collar worker that looks up things I don't understand.) I did have debris in the old oil nothing made it past the screen though that I saw.
Is the only way to test the hub marking by putting it in the water? Or can I do that in the driveway? The lake is an hour drive away.
The permanent marker pen is used to make a line through the outer prop hub and the inner hub.
In other words, you would draw a line through both.

The propeller must undergo in-the-water-thrust in order to place enough torque against these two components.

When back on the trailer, if the outer hub and inner hub have shifted, then you know that the hub is bad.
In other words, if your marker pen line has shifted, the propeller hub is not holding.