VP 280 Manual typo and other questions

"1977 280 outdrive

1) O

"1977 280 outdrive

1) On page 114 #37 (link is below)In the calculation for measuring for shims, a clearance dimension of 0.24mm calculated. A shim thickness of 0.24mm is recommended, allowing for a remaining play of 0.04mm. Shouldn't the shim thickness be 0.20mm, leaving 0.04mm clearance?

http://www.thestraycat.net/files/Volvo%20Penta%20Workshop%20Manual.pdf

2) Preparing to measure for shims between the lower and mid sections, shouldn't the bearing race easily drop in place in the recess in the lower unit? Mine does not. The fit is very tight.

3) The bolts holding down the tilt mechanism (30 years old) on my 280 drive are rusted into place and corroded. I am thinking of grinding away the base of the tilt mechanism (yes I need a replacement, Ricardo) allowing a maximum amount of bolt remaining to attempt removal. Any problems torching in this area? Any other suggestions? PB Blaster will be used as well. If I shear of those bolts I will have a MAJOR problem.

Thanks
Jay}"

"[b]This is considerably diffe

"This is considerably different from shimming a transmission to an Intermediate housing!
BTW, you are looking at set-up information for a Duo Prop lower unit. There was no duo prop 280 in 1977.

There are three bearings on this vertical shaft. Of the three, the two upper bearings control the "drive" gear depth to the two "driven" gears...... or a single "drive" gear into a single "driven" gear.
With either, there is an angular contact bearing directly underneath the tapered roller bearing. Each performs a different and opposite task.
The angular contact bearing is by now non-adjustable. We can only set the tapered roller bearing shimming when swapping units.

1) Are you needing this info for either a Duo Prop or single prop lower? If so, this roller bearing race shimming is the same for either lowers.
If you are wanting to shim the bearing race only, see notes below!

2) The race also provides an alignment here..... sort of like a dowel pin to align lower to Intermediate....... so yes, the fit can be fairly tight fit.
It can cause issues for us.
Take an instrument and de-bur the start of the lower unit bore for this. It may help some.
I often need my HUGE channel lock pliers to get a race back out.

3) Grind the heads off it you wish.... Your call! Use the drive fork arm to provide up-lift to the vice rod pressure plate by placing a piece of wood between the fork arm and pressure plate. Push down on the out drive. The lift unit should come up/out.


Notes:
a) dimension "A" is a difficult dimension to obtain without the Volvo Penta special tools.
Set the race onto the roller cage firmly.
Tap around the perimeter so that it seats!
Make certain that the vertical shaft is seated (down).
Take many "A" readings as you'll find that from one side to the other it will vary.
Tap/take another reading/tap/reading and so on. The race must be seated evenly in order to get an accurate measurement.
(an old style depth micrometer works very well for this)
Use the same instrument to check the depth of the bore in the Intermediate housing.
Calculate shim value.
Place the new shim value above the race into the bore holding them in place with grease.
Tap the race into Intermediate housing.

b) Use the race that was originally with the lower unit being installed! (we do not mix/match used bearing components)

d) The dimensions shown seem are somewhat varied from what I've been using. Here are the dimensions that I shoot for:
I aim for a Negative Pre load of .001" to .0015" here. (That is one thousandth of one inch.... not milimeters)
IOW's, the race against the roller cage will be relaxed to the tune of .001" to .0015".
<u>Not a POS pre load</u> as in other scenarios using a similar bearing and rolling torque specs!

Hope this helps! "

"So my procedure will be as fo

"So my procedure will be as follows

1) Press bearing race into top of lower unit, tap down until well seated.

2) Measure with depth micrometer all around. If measurements not consistent, tap all around again and remeasure until consistent.

3) Use Channel-locks to remove bearing race.
from lower unit bearing cage.

4) Measure depth in midsection.

5) Subtract the two measurements.

6) Add shims, (if necessary) to allow for 0.001 to 0.0015" clearance (free space)

7) Place shims in mid-section, use grease to hold in place. Tap in bearing race, seat well, use depth micrometer to be sure is seated evenly and completely.

Please let me know if this isn't correct.
Thanks
Jay"

"Jay, regarding some clarifica

"Jay, regarding some clarification to your #5 & #6;
Subtract the dimension of the top-of-race-to-deck-surface (of the lower unit) from the dimension of the "bore" in the Intermediate section....... then minus the clearance that you are shooting for......
That will be your shim value.

Regarding your #7...... Doubt that you will need to take any further dimensions unless you were to suspect that a shim became cocked in the bore. (This is where the grease works well.)
Place the thinnest shims above the heaviest shims for holding power.

."

Thanks Rick. Now where do I ge

Thanks Rick. Now where do I get the shims? Does anyone know if the host of this website carrys them?

"These particular lower unit/v

"These particular lower unit/vertical shaft race shims are used in all of the AQ series drives. AQ 200 up through current.

To my knowledge, they are a volvo penta OEM item only."