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Volvo 275 gear.ratio

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japato11

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 i have a 1986 bayliner 2450 ciera
it has a 260b engine with a 275 volvo outdrive
the id plate on the outdrive is partially worn out from age
i have been looking thought alot of the forms

i am to find out what gear ratio my outdrive is
is there is anyone that can help me out





 
None of us will actually be able help you with your over-all ratio unless we were right there with you.

If the PZNR tag was there and readable, it's only good if no one has swapped lower units.
Originally (with your engine), the number would end with "B", designating the 1.61:1 final or over-all reduction.

Remove the propeller, and the prop shaft ring anode.
Wire brush the aft-most area of the bearing carrier.
The ratio will be stamped into the carrier, and will be good ONLY if a gear set change has not occurred.
Hopefully you'll see 1.61 (they omit the : 1)


In/around this model ..... all transmission reduction is same.



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Thank you
i will take prop off to find the numbers


I dont know if I need to start another thread for this


I was looking into getting a rebulit 275 or 280 duel prop drive
But almost all these outdrives have deferent gear ratios from what I my have
and Volvo Manuel does not tell me if or how to mount deferent drives to my 260b motor.
Di you know if I can swap vp aq outdrives with this motor .do I need peace upper and lower sections or is there a adaptor
that can go from universal joint to bell housing


I am trying to explain this the beat I can
 
japato11 said:
I was looking into getting a rebulit 275 or 280 duel prop drive
You may find a 280 DP, but it would be one of the first Duo Prop drives from around 1983.


But almost all these outdrives have deferent gear ratios from what I my have
Yes... the single prop drive ratios are quite different from the Duo Prop drive ratios.
BYW... with exception to the "E" drive, all ratio changes occur within the lower unit.


and Volvo Manuel does not tell me if or how to mount deferent drives to my 260b motor.
The Duo Prop lower unit is all that's required.
(w/ the C and later unit, the long vertical shaft coupler is required)
The Duo Prop lower unit will mount to your existing Intermediate housing.
(the correct shimming procedure must be followed)


Di you know if I can swap vp aq outdrives with this motor . do I need peace upper and lower sections or is there a adaptor
that can go from universal joint to bell housing

There is no need to swap entire out drives..... only the lower unit.
Your engine demands the 1.95:1 lower unit.

NOTE:
The actual reduction is a combination of the transmission reduction and the lower unit reduction.... rendering this a 1.95:1 over-all ratio.
Click to expand...

Here is an AQ series Duo Prop lower unit that is mounted to a 290 or SP Intermediate housing and 290 or SP style transmission.

375_500_csupload_46572068.jpg





Here is a similar DP lower unit mounted to a C or later Intermediate and transmission.
(note that the Ring Anode is missing)

3.jpg



The mounting surface is identical to that of the single prop lower unit.
Make sure that you get the vertical shaft tapered roller bearing race with the DP lower unit.
This is the race that will need to be shimmed correctly for the different lower unit housing.


Gear oil now changes from Engine Oil to GL-5 gear lube.



If you find a good used DP lower, ask if they'll pull the prop shaft bearing carrier out so that you can look at the gears and several bearings.
No change to the shim value occurs.
Two new O-rings.... and it's back exactly as it was prior.

You'll need a pulling tool similar to my design shown here.

DSC01715.jpg





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By the way....... any of the main stream AQ series Duo Prop lower unit in the 1.95:1 ratio can be made to work with your existing drive components.

Volvo Penta's first counter rotating propeller drive was introduced in 1983 as the 280 Duo Prop.
This style drive ran into the mid 90's as the Duo Prop or DP....... not to be confused with the DP-S drives, of which also ran into the 90's and later.

Any of the pre- "C" DP lower units will require the short vertical shaft spline coupler.... same as what you now have.
Any of the "C" and later DP lower units will require the long vertical shaft spline coupler.

This is due to a change in length of the lower unit vertical shaft.




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RicardoMarine said:
By the way....... any of the main stream AQ series Duo Prop lower unit in the 1.95:1 ratio can be made to work with your existing drive components.

Volvo Penta's first counter rotating propeller drive was introduced in 1983 as the 280 Duo Prop.
This style drive ran into the mid 90's as the Duo Prop or DP....... not to be confused with the DP-S drives, of which also ran into the 90's and later.

Any of the pre- "C" DP lower units will require the short vertical shaft spline coupler.... same as what you now have.
Any of the "C" and later DP lower units will require the long vertical shaft spline coupler.

This is due to a change in length of the lower unit vertical shaft.





Thank you for all this great information
learned a lot
Click to expand...
 
japato11 said:
RicardoMarine said:
By the way....... any of the main stream AQ series Duo Prop lower unit in the 1.95:1 ratio can be made to work with your existing drive components.

Volvo Penta's first counter rotating propeller drive was introduced in 1983 as the 280 Duo Prop.
This style drive ran into the mid 90's as the Duo Prop or DP....... not to be confused with the DP-S drives, of which also ran into the 90's and later.

Any of the pre- "C" DP lower units will require the short vertical shaft spline coupler.... same as what you now have.
Any of the "C" and later DP lower units will require the long vertical shaft spline coupler.

This is due to a change in length of the lower unit vertical shaft.





Thank you for all this great information
learned a lot
Click to expand...





I am working on my upper housing and was wondering what type of tool or tools do I need to use if I have to change the gears or bearings to measure the shims that I have to use and where I can get it

Also when I recondition the upper housing should I replace all
o rings and seals for the entire
drive

Thank you
Click to expand...
 
japato11 said:
1.... I am working on my upper housing and was wondering what type of tool or tools do I need to use if I have to change the gears or bearings to measure the shims that I have to use and where I can get it


2..... Also when I recondition the upper housing should I replace all o rings and seals for the entire
drive
Click to expand...
1... Do you understand hypoid gear and bearing work?
No offense, but if not..... you may want to have an experienced person help you.


Unless damaged..... I highly doubt that you'll be replacing the gear set!




2..... Yes!




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RicardoMarine said:
1... Do you understand hypoid gear and bearing work?
No offense, but if not..... you may want to have an experienced person help you.


Unless damaged..... I highly doubt that you'll be replacing the gear set!




2..... Yes!





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Click to expand...
Thank you for all your great advice
one thing




We. Have. One. Bolt. Left. To. Get. Out. Of. The. Upper. Housing. Can't. Use. Allen. Wrench. Because. Opening. Is. Rounded. Out. Do. You. Have. Any. Ideas. On. What. To. Do. Other. Three. Bolts. We're. Rusted. Out. Very. Bad. Also. How. Can. Water. Get. Into. That. Section. Of. The. Housing. To. Cause. All. The. Bolts. To. Be. Rusted. That. Bad
 
japato11 said:
Thank you for all your great advice
one thing
We. Have. One. Bolt. Left. To. Get. Out. Of. The. Upper. Housing. Can't. Use. Allen. Wrench. Because. Opening. Is. Rounded. Out. Do. You. Have. Any. Ideas. On. What. To. Do. Other. Three. Bolts. We're. Rusted. Out. Very. Bad. Also. How. Can. Water. Get. Into. That. Section. Of. The. Housing. To. Cause. All. The. Bolts. To. Be. Rusted. That. Bad
Click to expand...
This is why an experience person would have been beneficial to you.

Your drive shaft bellows have leaked, and may have been leaking for some time.
Water has entered an area where it should not have.
The socket heads have become rusted.
Worse than that (if not a 275Atransmission), the threaded areas are "wet" areas on the 275 transmission.
Heat is to used at the area of the thread "inserts" as to expand the area prior to any bolt extraction attempts.


There is a delicate shoulder just behind the cap screw socket heads.
If this shoulder is damaged during a bolt "drill-out" attempt, the new cap screw head will not seal.

Your transmisison must not be taken to a good machinist with a milling machine.
The transmission will be placed AFT-most face down flat on the machine bed, and clamped into position.
The machinist will now mill out the hex socket head ONLY, while NOT disturbing the delicate shoulder area.

He will machine down to all but the last 1/2" or so of the remaining cap screw.
Once this is done, the Bearing Box clamping collar, along with the bearing box, will be removed.
Once removed and out of the way, now the remaining bolt fragment can be extracted from the main gear case.

Been there/done this many times when a DIY'r attempts to disassemble one of these without using heat.
In extreme cases, I've had to do this with several of my own disassemblies.

If I don't get timed out, I'll have a photo here for you shortly.
Otherwise, I'll post again a bit later today.
 
I put several images together for you.

Do what it takes to salvage this clamping collar.
A new collar will run about $380, and will require re-shimming at either side of the bearing box stop collar flange.
 

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RicardoMarine said:
1... Do you understand hypoid gear and bearing work?
No offense, but if not..... you may want to have an experienced person help you.


Unless damaged..... I highly doubt that you'll be replacing the gear set!




2..... Yes!



How can I tell if I have a 275 TRANS or 275 a



we have the ujoint and collar out from the housing
We notice the shims are corroded between collar and gear box
All the gears and bearings look in good shape

These shims will have to be replaced
if I get the new shims same thickness
will I need to do testing or can I put it back together
With these new shims with new seals and orings


thank you
Click to expand...
 
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