AQ280 - Gear Ratio?

[CAminitruck]

I have a '76 Fiberform 22.5 Cuddy with an AQ240/AQ280 inboard/outboard. I'm trying to figure out what gearing is in the 280. Serial number has been damaged (lucky me), but definitely has first 3 digits 282 and last digit is 7.

Anyone know how I can figure out what gear ratio is in the outdrive? Volvo/Penta has a nifty overview document, listing 3 possible gear ratios (1.61:1, 1.89:1, 2.15:1), but unlike the AQ270 they don't seem to use the B/C/D designation in the serial.

Thanks in advance!

 

[captmello]

Re: AQ280 - Gear Ratio?

Welcome!

Most V8 engines are mated to a 1.61:1 ratio outdrive.

 

[CAminitruck]

Re: AQ280 - Gear Ratio?

Welcome!

Most V8 engines are mated to a 1.61:1 ratio outdrive.

Thanks!

Is there any way to confirm this on the drive itself, short of a tear down? If it was a differential, I'd just turn the input shaft and count rotations... not sure if there's a comparable trick for outdrives (one that doesn't require uninstall of outdrive or engine, preferably)

 

[Don S]

Re: AQ280 - Gear Ratio?

Thanks!

Is there any way to confirm this on the drive itself, short of a tear down? If it was a differential, I'd just turn the input shaft and count rotations... not sure if there's a comparable trick for outdrives (one that doesn't require uninstall of outdrive or engine, preferably)

Outdrives are the same thing. Put it in gear get the lash out of the gears in the drive. 1.6 turns of the crankshaft = 1 turn of the propshaft you have a 1.61 ratio.

You might also look under the prop anode. They stamped the ratio in the bearing carrier housing.

Of course, the drives are old, and who knows what's been changed or replaced, so the markings might not mean anything at all.