270 outdrvie swap to a 280

I have an aq225e with a 270 outdrive, went to change bellows and found water, cross bearing assembly rusted, and carbon washer destroyed. Have a chance to purchase 2 complete 280 outdrives, from flywheel to prop for 200$. Also willing to throw in a set of trim tabs including pumps. Both are V8 set ups, saw engines in one boat. Is it possible to just change upper gear box or should I change complete outdrive? One outdrive was fresh water only. Will this swap to my set up without modifications? Any input would be appreciated.Thank you, the guppy.

Guppy, the answer is YES. The 280 transmission will mate to your 270/275 Intermediate housing.
If these are 280's, the oil fill plug will be at about 1:30 O'clock position just above the eccentric piston housing.
Check the drive shaft female yoke........ you may find a course spline or a fine spline.

However, you will need to re-shim when a different transmission is installed on an Intermediate from another set up.



Make sure that the two mating surfaces are clean and free from debris.
Remove the old O-rings and toss them (you'll need new O-rings).

With the extra shims that you'll end up with........., grab a random amount, and slightly over-shim underneath the new 280 transmission.

Without the two NEW O-rings yet installed, fit the transmission onto the Intermediate housing, and just snug it down.

You'll be taking a feeler guage reading around the perimeter between the two. Take a number of readings.
The feeler guage reading should be in excess of .004". If not... add another shim and repeat the above.

Now remove the 280 transmission, and measure the random shim pack value.

Reduce this shim pack by a value that will give you a .003" to .004" over-value when finally re-installed and just snugged down.

With the NEW O-rings installed, now re-install the transmission, and tighten it fully down.
Ideally, you'll end up with ZERO clearance between the two.

The goal:
Both cases tight to zero clearance between them..... yet with a .003" to .004" squeeze against the lower driven gear bearing.

The squeeze is to prevent the bearing's outer race from spinning within the Intermediate housing.


NOTE: The Volvo Penta OEM work shop service manual will suggest using the codes that are stamped into each component.
However, the method above is actually easier, and IMO, more accurate.


BTW.... there's no need to remove the entire drive for transmission R&R.
Remove the upper transmission only, and you'll save yourself from un-necessary work.

If you have removed the entire drive (or if you plan to hang one of the complete 280s) .... hang the Intermediate and lower unit first..... then the transmission last.


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BTW.... your AQ225E might be a 275 drive.


275 tell tale signs:

prop shaft will be internally threaded for the center spinner keeper bolt.
oil fill plug will be above the eccentric piston housing.
exhaust outlet housing extends past the main housing a bit.



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I'd swap the whole drive... keep in mind that the 280s require a long hub prop which is not likely to be the type on your existing drive. I did a total 280 for a 250 swap some years ago. It was totally "transparent", i.e., disconnect hoses and cables, remove helmet bolt and pivot pins.
Since you did not install the present drive and the condition of the pivot pins is unknown, I'd suggest removing the transmission section from the center section so you can drive the pivot pins outward from the center ( the reverse of the usual)... This will save you pile of trouble if the previous owner/mechanic mushroomed the head of the pivot pin while driving it in from the outside. Use something SOFT, i.e. brass or aluminum and only about 1/2 the diameter of the pin while doing this. Do not reuse the plastic bushings.
In "new" condition, lubed with waterproof grease, these pins ( if not supporting the weight of the drive) should move with fingertip pressure. If drive weight is "hanging" on the pins, removal will be "less easy". Boat should be oriented so that the drive hangs straight down with at least some clearance to the ground. Gently driving a wooden shim under the skeg while in this position, will allow you to "unload" the pins from supporting the weight of the drive.
If the holes on the "transom plate" that the pins slide into are sloppy, consider swapping out the transom shield as well.

Removing/replacing the transmission to remove the drive per RICK's post, to me, is a "mixed blessing". While treating the transmission part separately from the rest of the drive so as to make reattachment of the input shaft and bellows easier, you will then have the additional work of removing ALL of the sealant residue used by the previous mechanic from both the intermediate housing ( careful not to get crap into intermediate housing internals!!) and from the transmission, then resealing and re pressure/vacuum testing the drive.

Capt Bob.... with the utmost respect.........

sandkicker said:

..........keep in mind that the 280s require a long hub prop which is not likely to be the type on your existing drive.
Bob, any drive including and past the 275 (which he may have mistaken for a 270), can use either length prop hub length.
All single prop drives net the same length prop shafts when the correct spacer/line cutter is used.
250, 270 and 275 require the short spacer/line cutter..... 280, 285, 290 and the SP require the long spacer/line cutter.

The difference is in which spinner is used.
Short hub prop....... full spinner with either the tab washer or with the center keeper bolt.
Long hub prop....... AFT-most part of the 2 pc spinner with the center keeper bolt.

I did a total 280 for a 250 swap some years ago. It was totally "transparent", i.e., disconnect hoses and cables, remove helmet bolt and pivot pins.
Yes.... all Pre-power trim transom shields (250,270,275,280,285) will allow for the different Pre-power trim suspension forks to hang from them.


Since you did not install the present drive and the condition of the pivot pins is unknown, I'd suggest removing the transmission section from the center section so you can drive the pivot pins outward from the center ( the reverse of the usual)... This will save you pile of trouble if the previous owner/mechanic mushroomed the head of the pivot pin while driving it in from the outside. Use something SOFT, i.e. brass or aluminum and only about 1/2 the diameter of the pin while doing this.
Fully agree!
Also heat the aluminum pin bosses to gently expand them.

Do not reuse the plastic bushings.
Bob, I do agree, but I also see no reason that these bushings cannot be re-used if in good condition.




Removing/replacing the transmission to remove the drive per RICK's post, to me, is a "mixed blessing". While treating the transmission part separately from the rest of the drive so as to make reattachment of the input shaft and bellows easier,
This is why we do it this way!

you will then have the additional work of removing ALL of the sealant residue used by the previous mechanic from both the intermediate housing ( careful not to get crap into intermediate housing internals!!) and from the transmission, then resealing and re pressure/vacuum testing the drive.
Bob, again.... with the utmost respect...... I view this as necessary when swapping transmissions.
And BTW... many mechanics use grease only.... although I do prefer Perfect Seal.

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If anyone can help me, I am looking to see the value of a Johnson Outboard, Super Seahorse rx11A

I know this is really off subject, but I am having a lil trouble figuring this forum out. I will periodically check my messages, if someone can help me.

Nothing to add to either of you two guys, you're just quicker at the keyboards. Add me to the list of "grease only" guys as that's the way I was taught.

boatdoc55 said:

Add me to the list of "grease only" guys as that's the way I was taught.

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Yep.... Volvo Penta has recommended grease "only" in the beginning. After having seen these for as long as I have.... my assessment now is, that grease is OK for boats that will not see salt water. If they do see salt water, the grease eventually turns into a white powdery substance.

QuickSilver's Perfect Seal is what I now use exclusively. Easy to clean up with a bit of heat and/or chemicals when we go back into them.

But as they say; "Each to his own!"



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Rick, Since dirt was new, 90% of my work has been saltwater. The only white powdery stuff I've seen was the factory assembly stuff they use to use. I've got customers that I've been taking care of their boats for 20 years and the grease is still grease. Blue wheel bearing grease. But as they say" each to his own".
Had one instructor, later on in life, tell us he didn't believe "any" was needed and that VP never said anything about sealant at all.

boatdoc55 said:

But as they say" each to his own".
Had one instructor, later on in life, tell us he didn't believe "any" was needed and that VP never said anything about sealant at all.

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Per my edition of the Volvo Shop manual, Permatex #3 is specified for reseals...

Also per same manual... 1.61 reduction drives, i.e., for V8s and V6s require long hub props, while the other reduction drives, can use the short hubs... Also the prop guide for vintage Volvos also specifies long hub props for V8s and the engine in this case is a V8.

I developed a technique that if the boat is blocked high enough so that the drive will clear the ground by about an inch when fully down, that allows me to remount a fully assembled drive in about 15 mins. Unfortunately, the last time I had to remount my drive, the boat was blocked lower, i.e, drive hit the ground before it was fully down and I had to resort to Rick's method.

Bob, I've been around AQ drives for 35 years and when I first got into the game there were not any long hub props, V8 or otherwise. I'd love to know what manual says to use some kind of sealant, as I have not had to use a manual for about 30 years.

Thanks for all the replies, couple quick questions. One transom shield has 2 shift cables, fly bridge? second what oil would you recommend? Leaning toward the idea of switching out female slide yoke, course spline to fine spline, and swapping out complete unit. Have small hand vacuum pump to test with.