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is shim required on 270 if the upper gear box fits the intermediate housing spec without shim

T

tmcboat

Regular Contributor
Hi All,
per the 270-280 workshop manual section shimming upper gear box in intermediate housing I measured B= distance from upper gear box to where shim is in intermediate housing= 19.79mm A= height of the upper gear head bearing=19.49- subtract B from A 19.79mm-19.49mm = .30mm then add .06mm to preload the upper gear head bearing. I installed the upper gear box into the intermediate housing and I get .36mm with my feeler guage so do I need a shim?
there is a small space difference between the front and back of the upper gear box- about .03mm. Can I use permatex ultra black sealant to bridge the gap ?
thanks,
tmcboat
 
Turn the upper gear housing on it's top, making sure the lower bearing housing is up against it's shims which are between the bearing housing and the aluminum housing. Measure the depth from the outer bearing race and the aluminum housing. Write that number down. Now measure the depth of the corresponding bearing recess in the intermediate, write that down. Now add the two together plus .004 and you got it. Sorry, I don't do MM.
 
You can use Volvo Penta's codes, or you can take the measurements as per the OEM work shop manual.
Or....... IMO, a more accurate method is this: (and I work in US inches, not Metric)

Toss a random value of shims into the bore of the Intermediate housing..... for example..... .008", .009" or even .010" more than suspected needed!

With O-rings removed (very important), set the transmission in place.

Snug all four fasteners down.... just snug, not fully tightened.

Take multiple feeler gauge readings around the space between the transmission case and the Intermediate housing.
Use the reading that you come up with the most often (you may see some wild readings).

Pull back apart and measure the entire random shim pack value.

Now reduce this random shim pack by a valuve that will leave you with an over-shim of approx .003" .

Example: if your random shim pack value measures .027", and your average feeler gauge reading is .010", reduce the shim pack by .007".... leaving you with a final assembled squeeze value of .003".

This will create a .003" squeeze on the driven gear bearing (prevents the bearing from spinning) when re-assembled tightly.
It will also allow the two cases to come within ZERO clearance of one another when fully tightened down.


As for the two O-rings and mating surfaces........... if in salt water, QuickSilver "Perfect Seal" works well.
Otherwise, I find that water proof grease works well.


Tip:
If the entire drive has been removed from the Transom Shield, re-install the Intermediate/Suspension fork and lower unit as an assembly.
Install transmission alone last.

This is much easier as it leaves the area open for water neck fitting S hose re-connection, shift cable re-connection and exhaust bellows re-connection..... and you won't be fighting the entire drive while also trying to align the female yoke, etc etc etc.

.
 
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Hi All,
thanks for the help--
one more thing-- When I took the linkage shoe out I do not remember which way the off set shoe goes back- in any tips or help wit this
thanks,
tmcboat-
 
The shift mechanism will only fit back into the gear case when the shift shoe is correctly installed!

While still disassembled, this would be a great opportunity to replace the eccentric piston seal!
 
the spring pin #62 was missing on the linkage control- I am ordering a new one- any tips on how to install it? also there is a round wire that holds springs in and its not available through the volvopentastore- any suggestions?
Happy 4th-
Thanks,
tmcboat
 
tmcboat said:
the spring pin #62 was missing on the linkage control- I am ordering a new one- any tips on how to install it? also there is a round wire that holds springs in and its not available through the volvopentastore- any suggestions?
Happy 4th-
Thanks,
tmcboat
Click to expand...

The only spring pin that comes to mind for me would be the spring pin (SEQ #62) for the eccentric piston "detent" pin (SEQ #63).

(BTW..... SEQ#63 is NOT a clevis pin as the parts list suggests! It is the neutral detent pin.)


7908.jpg

If that spring pin was missing, I'm almost certain that the detent pin would have come loose by now.


As for the detent ball retaining wire:
If you push a cylinder (such as a socket) into the eccentric piston bore (as you remove the piston), the wire will not need to be cut, and the detent balls will stay put.
When you re-install the eccentric piston, the socket will be pushed back out.

Otherwise, if you cut the OEM wire, be sure to use new wire that is intended be used as safety wire.
Safety wire will take the twisting, whereas some other wires may break later on.

Don't forget that the new eccentric piston seal is directional.


Back to the detentpin "spring pin".
You'll see two styles of spring pin bores.... one will be perpendicular to the eccentric piston (as shown in the schematic)..... the other will be parallel to the eccentric piston.
If yours uses the parallel bore, the old spring pin must be retrieved from the bore!
Failure to retrieve this pin will result in never again being able to remove the spring pin in order to change the eccectric piston seal.

Spray carburetor cleaner down into the bore...... it will dilute the oil, and the pin should come out with a few mild taps.



.
 
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I have a solid pin that sticks out of the piston which goes up and down when I move the linkage. I have a hole in the piston housing that is at an angle and on the other side of the housing there is a smaller hole you can see through to. Is a solid pin supposed to go in this hole? Or is there a tiny spring -can't really see- that goes in there?
 
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