1973 AQ 225D 280 Outdrive install in Searay

I am installing an AQ225D with 280 DP outdrive in my 1973 24' Searay. It came from the factory with either a Mercruiser or OMC not sure as they were both offerings for this boat. It was gutted when I purchased it. My question has to do with how to properly position the motor mounts. I have attached two pics showing stringers where the motor is to be mounted. As you can see I cut the caps off the stringers, as there was some water intrusion. Had to remove some foam and some rotted wood. Fortunately it was minimal with no damage to the stringers or transom. I am considering pouring some new foam about half full then bedding some aluminum backing plates in epoxy with Stainless lag bolts. My question is how to accurately position these. The centering is no issue my concern is the proper distance from the inside of the transom. I have considered two options.

1) Install the Transom Shield first then take measurements from there to position the bolts.
2) Cut slots in the aluminum backing plates so the bolts can be adjusted fore and aft. Then when the motor is in and bolted up I can poor in thickened epoxy.

Any thoughts on these or other methods.

Re: AQ 225D 280 Outdrive install in Searay

Doug, first off, I can just barely see in the one photo, that this was Mercruiser, NOT OMC.
This is good.

OMC would have been a "Stringer Drive" during this year, and would have had a very large opening in the transom.
This would have required an infill to the original transom hull shell in order to bring it down to the Volvo Penta size opening.
With what you have there, all you need to do is open this up as to fit the AQ series transom shield.

If you are near a boat salvage yard, they may be willing to give you a transom section from a donor boat that is about to be taken to the land fill.
Peel the wood core from the fiberglass shell, and use this for your lay-out and cut-out template.
Check your template fit on your transom shield first....... as you can imagine, not all were done with precision.

I would use only Fir Wood in your engine mount towers..... there should be no need for any metal components... and I would NOT use any foam.
Your build-up should consist of resin wet matting applied to plywood layers (matting between each layer), and chinked as you go, etc.
It does not need to be one solid piece of dimensional lumber.
Fir is a much better choice of woods........ no pressure treated wood of any type...., period.
No matter what you do, it will end up being much better than what the factories were doing back then...., sad as that may be.

Also, this age boat will be a Polyester Resin built hull. You can do Epoxy, but I'd stay with Polyester.

See this link, and subsiquent links, for transom shield installation tips.
There are also links that will help you with most any AQ drive issues... including the shimming of your Duo Prop lower unit.
Do not forget the importance of replacing your PDS bearings/seals. (see related links)

Have fun!

.

Re: AQ 225D 280 Outdrive install in Searay

Thanks Ricardo, As always your insight is the best.

My only reason for considering adding some foam back in was to avoid creating a hard spot against the outer hull. I was considering an aluminum backing plate to avoid any possibility of the bolt heads pulling through the wood. Your thoughts on those issues?

btw I found a local Volvo Penta certified dealer that has a good rep that is doing my DP lower unit for $ 150 + parts. For that price I decided to let them do it. Helps me as far as schedule as well because i am trying to finish everything and splash it Memorial Day weekend.

Thanks again, Doug

Re: AQ 225D 280 Outdrive install in Searay

Thanks for the kind words, Doug.

douglcfl said:

My only reason for considering adding some foam back in was to avoid creating a hard spot against the outer hull.
This portion of the hull is very strong. I think that you are worrying needlessly.

I was considering an aluminum backing plate to avoid any possibility of the bolt heads pulling through the wood. Your thoughts on those issues?
If you use a good grade of Fir plywood.... Marine would be excellent, but not required...., I think you'll do just fine.
Choose new lag bolts that have some depth to the threads (not bolt length) that will "bite" into the core material, and perhaps steer clear of the cheap Chinese bolts.


btw I found a local Volvo Penta certified dealer that has a good rep that is doing my DP lower unit for $ 150 + parts. For that price I decided to let them do it. Helps me as far as schedule as well because i am trying to finish everything and splash it Memorial Day weekend.
Well I sure hope so. But allow me to offer you a word to the wise, if I may.
Many of the older men, like myself, are no longer working in the trade. This leaves the younger guys who may have begun during the mid to late 90's. These guys did not cut their teeth on the AQ series drives.... they trained on the later drives.
I'm not discrediting them, but many just do not want this older AQ series Volvo Penta work, and when they do take it on, their interest is just not there.
And what a shame, because these are truly the most easy drives to work on due to the excellent design and engineering.
It's also shame that Volvo Penta got away from this AQ series drive and went to the Gimbal system drives. To me, this was a shot in the foot.

Click to expand...

I just recently spoke with a Canadian man who shared a story with me. He shared it with me, because ultimately he questioned something:

He buys/sells Volvo Penta parts, and he recently met a young Volvo tech who he says seems very sharp. They got into a discussion regarding rolling torque values for the Volvo main drive gear bearing box. The young man preceded to tell him that he uses an inch pound torque wrench on all rolling torque values. Well, this is great, but only if the OEM specs call out inch pounds for the value. Many specs call out string line/spring scale pull for the values... of which do not cross over to Angular Torque values without calculations being done.
The young tech did not seem to delineate between the Spring Scale procedure and the Angular Torque procedure. This means that he may be sending AQ series drives out the door with an incorrect rolling torque value...... ending up in premature bearing failure.
Apparently he was factory trained, but perhaps on the newer Volvo Penta drives.... not the older drives. Who knows?

The other issue is that the older guys were gone by the time these drives became 25-30 years old, and the inevitable corrosion issues started showing up. This regards the thread inserts (all of these use an insert for female threads) and fasteners. The procedure here, is to use heat on the thread inserts, before attempting to remove the fasteners. If not, often the results are broken fasteners, ruined thread inserts, etc. What comes next, are costly replacement parts that the owner now must needlessly pay for. Had the disassembly been done correctly in the first place, this is avoided!
I often receive these drives from back east as a result of either the techs not wanting to work on them, or the techs have attempted, only to foul up an otherwise usable gear case...., one that now must be machined or replaced, in order to save the drive.

I have also seen well seasoned Volvo techs not understand the shimming procedure. The lower unit vertical shaft tapered roller bearing race for example; this is a "Negative" pre-load.... not a Positive pre-load, yet they often get this wrong. Again, this leads to premature gear/bearing failure.

So, if you have a good local guy, that is great! My suggestion would be to pick his brain as to his procedure on the older AQ series drives. Perhaps make certain that he understands that heat is our friend when it comes to disassembling most of these older ones.
These are actually very easy to work on when just a few simple tricks are learned.

I don't mean to wave a huge red flag in front of you... just rather a caution for you.

Re: AQ 225D 280 Outdrive install in Searay

Well the bells are ringing and the red flags are waving for me... I am going to go in and talk to them before I leave the drive. I want this done right. I know the guy that owned this before and he is an old timer that took great care of it so I know it is solid now and I want it to last.

Thanks again for all the advice.

Re: AQ 225D 280 Outdrive install in Searay

Who you calling "old", Rick!!! Well seasoned yes, not old. It's been 33 years on the best S/D ever made and like you I wouldn't want ANY other drive. I didn't know you messed around with the new style V/P. I thought you were like me and do AQ's only. To the O/P, please listen to Rick and us other "old" guys about your AQ series and it'll stay together for a long time, it has NO ware out built into it like all the newer drives do.

Re: AQ 225D 280 Outdrive install in Searay

boatdoc55 said:

Who you calling "old", Rick!!! Well seasoned yes, not old. It's been 33 years on the best S/D ever made and like you I wouldn't want ANY other drive.
I didn't know you messed around with the new style V/P. I thought you were like me and do AQ's only.
To the O/P, please listen to Rick and us other "old" guys about your AQ series and it'll stay together for a long time, it has NO ware out built into it like all the newer drives do.

Click to expand...

Thanks for the kind words, Gary!

BTW, the AQ series Volvo Penta drives extended into the mid 90's..... ending with/around the C-1 drives, including the X drives, etc.
When they began with the Gimbal'd system, is when I lost interest!
What a shame!

Re: AQ 225D 280 Outdrive install in Searay

You guys have me sold. I've never owned one before but can't wait to get it in the water and experience it. I am going to be looking for a good deal on another DP 280 to pick up and rebuild as a spare. Give me a chance to learn as well as having it hanging in the garage just in case...

Doug

Re: AQ 225D 280 Outdrive install in Searay

douglcfl said:

You guys have me sold. I've never owned one before but can't wait to get it in the water and experience it. I am going to be looking for a good deal on another DP 280 to pick up and rebuild as a spare. Give me a chance to learn as well as having it hanging in the garage just in case...

Doug

Click to expand...

Doug, please note that a Duo Prop lower unit over-haul is often cost-ineffective.
Plus, this is nothing for the inexperienced or untrained to attempt.
Gears/bearings/seals/labor.... all add up very quickly.

IOW, don't spend $700 - 1,000 on a lower unit that needs gears/bearings.

I've seen people pick up a DP lower unit for this amount.... thinking that they got a bargain....., only to later learn that it requires much more cost to repair, than if they had spent a bit more for a good working DP lower unit.
The cost for labor alone during set-up, will make spending a tad bit more seem much more practical.
Avoid the shot in the foot, so to speak.

Re-sealing is another story..... re-sealing a DP lower is a cake walk and is inexpensive.


.

Re: AQ 225D 280 Outdrive install in Searay

I started working on prepping my DP lower for paint and decided to drain the oil. It has been sitting a while and I wanted to see what it looked like. It looked fine at first but as it got lower it started to look a little milky and the last bit was almost brown and felt a little gritty. Should I be worried and what can I do to thoroughly check the lower?

Doug

Re: AQ 225D 280 Outdrive install in Searay

I started working on prepping my DP lower for paint and decided to drain the oil. It has been sitting a while and I wanted to see what it looked like. It looked fine at first but as it got lower it started to look a little milky and the last bit was almost brown and felt a little gritty. Should I be worried and what can I do to thoroughly check the lower?

Doug