Trying to find correct part no. for 270 pinion gear needle bearing

I am rebuilding a water damaged Volvo Penta 270 outdrive, Serial 2745789C, built around 1975. It’s a dual bearing PDS and it was attached to a Waukesha assembled power pack that included a 165 HP Ford 302. We couldn’t find any numbers on the engine other than the Ford serial and casting numbers that indicate the engine was built in 1975. Apparently, Waukesha bought out all or part of PCM to get into the recreational boat business. PCM eventually bought the business back.
The boat is a Spacecraft Royal Flush. Only two were built. This pic is the dual steering prototype. We believe the one we have is the single steering production model.
I have to replace the lower unit pinion gear needle bearing and the all the parts diagrams I can find call for a 183497 bearing. I found some pics on ebay of that bearing, but it looks different that what I removed. It appears that that the 183497 has an inner and outer race and a needle carrier. The original one has no inner race, the inner race is part of the gear, and there is an upper and lower needle thrust washer.
I finally found a number in a 270 diagram that called out a 183394 bearing. I only found one pic for it. VP diagrams call it obsolete. It doesn’t really look much different from the 183497.
I may be missing something here, this is my first VP lower unit teardown. I have called a couple of dealers, but they didn’t want to get involved.
Any information is appreciated.
Edit. Can't seem to get pics to upload. I resized and got them listed, but no upload.

Don

Don, the "C" lower unit is the 1.89:1 reduction. This reduction is used behind the in-line 6 and some of the V-6 engines.
You will spend more time and money replacing the "Drive" and "Driven" gears, the bearings, the seals and time on set-up than it's worth.

These (1.89:1) are a dime a dozen due to so few applications today.
Look on e-Bay for a good used 1.89:1 lower unit. It can be a 280, 275, 270.... it doesn't matter that much.

See the OEM service manual for the A and B dimensions so that you can properly shim above the vertical shaft tapered roller bearing "race", and be done with it.

Ricardo,
Thanks for the reply. As always, there is a bit more to the story.
When I tore down the engine to rebuild it I found it was one of the blocks Ford used in the early seventies that had a negative piston height of 035. in. I cc’ed the combustion chamber and piston crown and with the extreme piston height the compression ended up at 6.8 to one. The boat is quite heavy so I believe Waukesha asked for the 1.89 gear to compensate for the low horsepower (compression) and the weight.
I rebuilt the engine, raised the compression to 9.25 to one and added a four barrel carb. The engine now produces 305 HP @5500 RPM on the dyno. This boat is being restored for showing with some occasional easy cruising so I don’t feel it will be stressing the drive.
I agree with your advice, except as long as we have decided to go to another lower unit I would prefer to go to a 1.61 geared (B) version. I assume from what I can determine, that shouldn’t be a problem.
With all the time and effort that has gone into this project, I believe I will at least pull the prop shaft assembly out of the replacement to check the gears and reseal it. Thanks again for the help.

Don

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latemodel said:

Ricardo,
Thanks for the reply. As always, there is a bit more to the story.
No offense, but it serves you and the forum best if all the info is posted from the beginning.

When I tore down the engine to rebuild it I found it was one of the blocks Ford used in the early seventies that had a negative piston height of 035. in.
Did you mean to say .035"?

I cc’ed the combustion chamber and piston crown and with the extreme piston height the compression ended up at 6.8 to one.
That is far too low for a Ford V-8 Marine engine.


The boat is quite heavy so I believe Waukesha asked for the 1.89 gear to compensate for the low horsepower (compression) and the weight.
Very likely.

I rebuilt the engine, raised the compression to 9.25 to one and added a four barrel carb. The engine now produces 305 HP @5500 RPM on the dyno.
The important range will be at/near 4,000 RPM.

This boat is being restored for showing with some occasional easy cruising so I don’t feel it will be stressing the drive.
You will not stress this drive. They are exceptionally stout.

I agree with your advice, except as long as we have decided to go to another lower unit I would prefer to go to a 1.61 geared (B) version.
Yes, with the increased HP you will want to go with the 1.61:1 reduction.
Even while the 1.61 brings more money, you will still be better off if you were to find a good used one.
Do not forget the importance of the A and B dimension and the re-shimming above the race.

I assume from what I can determine, that shouldn’t be a problem.
NO..... you should do that.

With all the time and effort that has gone into this project, I believe I will at least pull the prop shaft assembly out of the replacement to check the gears and reseal it.
Yes, and this can be done without any change to any shim values.


By the way, when/if you were in need of replacing a "drive" gear (what you are calling a pinion gear), both the "drive" and "driven" gears must be replaced.
These are made and sold in sets only! We cannot mix/match hypoid cut gears.

Thanks again for the help.

Don

Click to expand...

Ricardo,
Thanks for the reply. As always, there is a bit more to the story.
No offense, but it serves you and the forum best if all the info is posted from the beginning.
Will do.

When I tore down the engine to rebuild it I found it was one of the blocks Ford used in the early seventies that had a negative piston height of 035. in.
Did you mean to say .035"?
Yes. I'll blame fat fingers and old age.

I cc’ed the combustion chamber and piston crown and with the extreme piston height the compression ended up at 6.8 to one.
That is far too low for a Ford V-8 Marine engine.

The boat is quite heavy so I believe Waukesha asked for the 1.89 gear to compensate for the low horsepower (compression) and the weight.
Very likely.

I rebuilt the engine, raised the compression to 9.25 to one and added a four barrel carb. The engine now produces 305 HP @5500 RPM on the dyno.
The important range will be at/near 4,000 RPM.
Torque peak is 320 ft.lbs. at 3500 RPM and stays flat to 318 ft. lbs. at 4200 RPM. It drops to 290 ft.lbs at 5500 RPM.

This boat is being restored for showing with some occasional easy cruising so I don’t feel it will be stressing the drive.
You will not stress this drive. They are exceptionally stout.

I agree with your advice, except, as long as we have decided to go to another lower unit I would prefer to go to a 1.61 geared (B) version.
Yes, with the increased HP you will want to go with the 1.61:1 reduction.
Even while the 1.61 brings more money, you will still be better off if you were to find a good used one.
Do not forget the importance of the A and B dimension and the re-shimming above the race.
I have found a 1:61:1 bought the complete unit.

I assume from what I can determine, that shouldn’t be a problem.
NO..... you should do that.

With all the time and effort that has gone into this project, I believe I will at least pull the prop shaft assembly out of the replacement to check the gears and reseal it.
Yes, and this can be done without any change to any shim values.


By the way, when/if you were in need of replacing a "drive" gear (what you are calling a pinion gear), both the "drive" and "driven" gears must be replaced.
These are made and sold in sets only! We cannot mix/match hypoid cut gears.
Understood. Circling back to my original question about the driven gear needle bearing, have you ever seen a needle bearing like this drive had? Loose needles with thrust rings top and bottom, and the drive gear acting as the inner race. It’s a moot point now, but I am curious if this is the standard setup, or something used in specific drives.

Thanks again for the help.

Don

.............................

By the way, when/if you were in need of replacing a "drive" gear (what you are calling a pinion gear), both the "drive" and "driven" gears must be replaced.
These are made and sold in sets only! We cannot mix/match hypoid cut gears.
Understood. Circling back to my original question about the driven gear needle bearing, have you ever seen a needle bearing like this drive had? Loose needles with thrust rings top and bottom, and the drive gear acting as the inner race.

Don..... yes, this was common practice. They did not have any issues doing so!

Click to expand...