Hi,
Just read over your beginning post.
Nice problem.

I usually don’t hang out on 900’s but I see your dilemma about sizes.
Have you posted this in the 240 section?
The late nineties cars used the same automatics from the Aisin Borg Warner of Japan relationship.
Lots of Toyota’s rear drives used them but I cannot say anything about a special bearing setup for the tail shaft and just for Volvo.
You might try the Toyota dealers, there could be an optional part number source with them being a larger user and inventory storage.

I have seen specials seals in limited cases made for mistakes like this.
Harley Davidson did this on front end fork shock absorbers in 1971 Sportsters.
I got one of those mistakes!
About 10 years later, I went to change oil seals with dealer seals but the dealer said they were “ Obsolete” all ready? Fine!
I then purchased standard seals based on the size of the chrome tubes.
I got into them and found two thinner wall seals in there from the factory.
Ah ha! A “change during production disclaimer“ just hit me!
The factory doesn’t supply that part. So, It’s not their problem now!
Under my factory one year warranty, the original chrome down tubes rusted and were replaced by the dealer.
They just move over the lower ends onto new tubes. Not the whole front end.
I had to machine out the bore lips of outer lower shock housings to fit the bigger standard oil seal O.D.
Luckily, I worked in a big machine shop and the bore in those large lathes swallowed that problem with its fender brackets and such still on them.

You might consider having the tail shaft turned to fit a standard bearing.
I have no idea what it looks like, so I cannot help you there.
A 30mm diameter is a nominal dimension and there is no engineering advantage and definitely not an economic one to be so slightly different.

The Seals I.D.’s are made, as standardization goes, to what size bearing is on the shaft, if the diameter runs out far enough.
If not the shaft diameter is sized to the next standard seal up or down.
Seals are much cheaper to redesign.
Again, the .47mm is weird. .5 or a whole 1.0 mm and that might be just as odd too!


Sometimes engineers paint themselves into a corner or into trouble and have to go special!
Maybe, tail end shaft had an issue with some other clearances during assembly or maybe not?
Things can get complex, if overlooked from prototyping, blueprints, supplies and on in to actual production of thousands of units!

There was a battle fought for years over English versus Metric, but metric has technically won out long ago!
That is, as far as, within inside the ball bearing, it is metric or the internal rolling elements get done.
The internal races of grooves and the “balls went to metric sizing and grading” for international reasons of production and shipping to various plants for assembly. Plus, to avoid taxation because it’s not a finished product ”loophole.”
The consensus in the bearing world it is, “As the world turns!” (:-)

Mostly it was due to failure of good quality material availability as it does varies from country to country.
In the 70’s the finished balls got rolled and bounced off a thick steel plate inside a box. They go on up into various specific holes in different directions and height.
This is for the material quality process and it’s sizing. Amazingly simple and fast. It kept prices down for many years!
It may have changed somewhat after this long of time as with new technologies are changing things. I can only imagine being retired from the machining trade so long.

Supply of the Outside and Inside diameters stayed up as an issue up for grabs of who made the most stuff. It’s about global demand for years now.
As far as I know, we stopped making bearings, made in the USA, in true USA sizes for about 25 years now. Several more societies of standardization work together.
It’s done everywhere now. Nothing exclusively from one place, except in exclusive, high dollar big size units.

The oddness of .47 of a mm is only .018.
That .047mm is really an anomaly to be runNing into production with, to me?
It’s good for it to be on the shaft as it can be made smaller or like you said the bearing made bigger.
In other scenarios, you sleeve the shaft up in size.
In Most cases the latter is more work.
If they moved the housing side up bigger in sizing, in a non-standard way, that would really make people hate those products to repair.
Housing are usually casted for minimum weight, so get larger, can weaken a case design.

I’m dreaming here, but if the 30mm size was missed during that “low tolerance” manufacturing and bearing manufacturing is, the internal race gets thrown into another pile.
Maybe, Those got routed into the Volvo special run or otherwise it’s scrap and gets melted again.
A maximum of .018 or less if over size, is within most grinding rework tolerances of production.
That much is left for hardening shrinkage in pre operational stages.

Volvo was always a lower in a production numbered vehicle, when you look wide at the spectrum of millions of cars per year.
Volvo expected higher costs for that reason alone and those two manufacturers probably haggled and gambled production waves in the future when contracting.
Eventually something runs out or changes in time.
Volvo 240 models had a longer and larger run than most of their cars! Aisin and Borg Warner shared the bliss with Toyota and Chrysler/Jeep.
All these companies lose some quality control when delegating responsibilities to outside vendors, especially, when it gets down to bottom line cost cutting contract issues!

There are at least 50 different manufacturers out there with several models galore.
The number of vendors for them compete like dog eat dog competition.
The car manufacturers play this game and we the consumer come up SHORT!

On about 85% of this game playing manufacturing are not as high of quality. Some say garbage or throw always? Their junked or are totaled out before the payments end.
”Parts No Longer Available,” for drive lines or the body parts for repairs by the insurance companies are limited to demand production only. Inventory is limited to the popularity of designer clothes and colors, nowadays!

Take your pick where the consumers SHORTS are in what is the fastest in depreciation contraption made by man today. The electronic gimmicks are outdated very quickly and are very dismissive to the used car trade!
A neighbor and her daughter with her bought a 2010 XC60 AWD with leather seats for $14K a few months ago. It has 96k in mileage.
Just guessing, but wasn’t that about $50K back then?

She is 89 years old and told me she doesn’t know how or why the outside mirrors fold in sometimes and then don’t, when she parks?
The Garage door opener is in it because she hasn’t figured out to program the car yet.
I’m glad for one thing, as I didn’t see a dash screen to distract her!

Luckily, a lot of us found a good designing manufacturer to stem our bleeding, with its previous years of production.

Phil