Any special tools needed

Still helping my son research a Volvo dual prop 4.3 I/O. I've got the tools for rebuilding an engine along with gear pullers etc. Are there any special tools needed to take apart and repair a dual prop drive??

Which year.... Which model Duo Prop????

Here's what I know about it. If there were more than one dual prop put on this engine in 1993, I'll call the owner.

Thanks.


http://minneapolis.craigslist.org/ank/boa/1792613752.html

In 1993, this could have been a DP-S, or one of the AQ series Duo Prop engine/drives.
According to the photos, this is one of the last AQ series, of which is what I work on.

So yes..... there are a few special tools that would be required to work on this drive.
There is also a crush sleeve and rolling torque value that must have close attention paid to (upper transmission unit) when removing the bearing box.
If you have prior Hypoid Gear experience, these are very easy to work on.
As with anything, the little "do's/don'ts" are the important things to know..... and we only gain this with experience.

BTW, this series drive does not get any better. This is the GOOD STUFF!
V/P shot themselves in the foot when they took over OMC and re-designed the Volvo SX and DP S drives in a Gimbal Suspension system, IMO.
The AQ series does not use a Gimbal affair.

Why don't you post what you propose to replace????

.

Hopefully there would be nothing that I or my son would have to deal with. The 2 boat dealers we've talked to weren't very positive about a dual prop-----and I've always preferred to work on my stuff my self. One was a Volvo service place, one wasn't.

I have some experience with hypoid gear sets and rolling torque bearing adjustments.

427435 said:

Hopefully there would be nothing that I or my son would have to deal with. The 2 boat dealers we've talked to weren't very positive about a dual prop-----and I've always preferred to work on my stuff my self. One was a Volvo service place, one wasn't.

I have some experience with hypoid gear sets and rolling torque bearing adjustments.

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FYI, the term is "Duo Prop", and if a Volvo Penta shop is NOT aware of the great performance benenfits of the "Duo Prop", then move on to another shop, because they obviously are not servicing them.... therefore it is doubtful that they could advise you!

I could link you to thread after thread re; the performance gains of the Duo Prop drives. I have yet to hear from one dissatisfied person who has upgraded to the Duo Prop.

Just to clarify; this is the Volvo Penta Duo Prop that we're talking about......, NOT the M/C BIII drive!

The Duo Prop technology works so well, that both Volvo Penta and CMD Zeus systems incorporate this technology for larger boats these days!
These are handling in upwards of 600+ horse power.

Thanks for the pictures-----still don't understand where the tilting takes place and how the power is transmitted through the tilting part. Are there a couple of u-joints or is there a constant velocity joint??

Here are a couple more pics I got from the seller.

There are a few things that I'd be concerned with, but nothing that would be a deal-breaker!
Both engine and drive appear to be well kept!

Make sure that the propellers can be removed.
Corrosion builds if these are not removed once or twice annually.
When they get stuck, you end up cutting them off! So make sure that both props can be removed..... and then grease the splines.

Here are two 275 single prop drive cut-a-way views.
Not quite the same, but the point of articulation is the same.
The later one that you are looking at, will have hydraulic trim/tilt cylinders, whereas these do not.

So is the drive on this boat an AQ drive??

I do appreciate the info you're providing.

Mark

427435 said:

So is the drive on this boat an AQ drive??

Click to expand...

Mark, yes it is!

RicardoMarine said:

In 1993, this could have been a DP-S, or one of the AQ series Duo Prop engine/drives.
According to the photos, this is one of the last AQ series, of which is what I work on.

Click to expand...

Hey Rick, don't you wish we got to work on boats that clean, that have never seen salt!!!! That's a beauty and one of the last of the REAL sterndrives.
Mark, make sure to pull the steering helmet back and check the bellows area for water, while you're there, have a look at the water intake nipple.

boatdoc55 said:

Hey Rick, don't you wish we got to work on boats that clean, that have never seen salt!!!! That's a beauty and one of the last of the REAL sterndrives.
Mark, make sure to pull the steering helmet back and check the bellows area for water, while you're there, have a look at the water intake nipple.

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By steering helmet, you mean the cover on the top, rear of the outdrive?? What should I be looking for on the water intake nipple-----corrosion?

Thanks again for the help.

Look at your engine/drive model numbers, and visit this site.

Open up a view schematics, and read some of the part descriptions. There will be some variances.
This will help you familiarize yourself with the drive.

RicardoMarine said:

Look at your engine/drive model numbers, and visit this site.

Open up a view schematics, and read some of the part descriptions. There will be some variances.
This will help you familiarize yourself with the drive.

Click to expand...

Let's see if I have this figured out. The reversing is done in the upper gear housing------is it a friction clutch of some kind or is it a splined or dog collar that engages one of two bevel driven gears driven by the drive bevel gear. By the way, the comment that my son took away from the Volvo/Penta dealer was that there were twice as many seals and bearing to give you trouble with the DUO-prop drive. How often are these a problem----especially in a fresh water only boat?? The only parts I've had to replace on my 33 year old Mercruiser have been the U-joints and bellows once (that's not counting props).

427435 said:

Let's see if I have this figured out. The reversing is done in the upper gear housing------is it a friction clutch of some kind or is it a splined or dog collar that engages one of two bevel driven gears driven by the drive bevel gear. By the way, the comment that my son took away from the Volvo/Penta dealer was that there were twice as many seals and bearing to give you trouble with the DUO-prop drive. How often are these a problem----especially in a fresh water only boat?? The only parts I've had to replace on my 33 year old Mercruiser have been the U-joints and bellows once (that's not counting props).

Click to expand...

Yes, all three upper gears are turning when the engine is running.
One drive gear/two driven gears.
The engagement is accomplished with a vertical shaft sliding sleeve and an apposing gear cup.
As either of the "driven" gear cups rotate, the smooth conical shaped sliding sleeve contacts the smooth apposing cup.
When the friction becomes great enough, we have smooth full engagement via steep cut internal spiral splines.
The sum of these engagment parts are called a "Cone Clutch".

I say "Bunk" to any idea that the seals in these rives are problematic. I have one here right now that has a black S/M seal. Black was original. Although it will be re-sealed, it passed my Press/Vac leak down test!

Drive shaft bellows on ANY drive should be routinely replaced!
You're asking for expensive trouble if you DO NOT!

Bearing Crosses are Bearing Crosses..... they also must be routinely replaced. The less articulation of a marine I/O application causes more point loading than if in an auto drive line application.
IOW's, they wear more due to point load, rather than rolling wear, IMO.

I'm not sure what your reservations are about this Volvo Penta drive.
This drive will outlast the M/C Alpha drive hands down.
No Dog Clutch gear engagment, NO Shift Assist, Only ONE shift cable.... and the Duo Prop performance gain is unmatched.

It's the unknown that I've always been careful about. Forty+ years of engineering machinery has helped make me that way. For some reason, I've never seen a Volvo I/O run or talked to anyone with one (let alone a duo-drive). Most of the boats of the size that's being considered are powered by an outboard.

On the other hand, I picked up a new 1972 Volvo 164 at the factory many years ago. Great car and was running strong at 175,000 miles when I got rid of it (it was so rusty by then, the kids made my wife drop them off a block from school)!!

Thanks again for all the info and help.

Volvo Penta pioneered the use of the Upper Unit Cone Clutch in a marine out drive years ago.... I believe it was in 1959. The design is basically un-changed today. That makes a HUGE statement, IMO.

Their Duo Prop lower unit design is basically un-changed since 1983, up to the model that you are looking at. This too makes a HUGE statement, IMO.

Mercruiser wanted the use of the Cone Clutch, but due to very well kept pattents, they could not until the mid 90's.