A bearing question for the experienced transmission builders

[raygreenwood]

A lot of people here who build a lot of transmissions. Some advice please.

I am doing a slow careful refurb and adjustment of a 004 transaxle from a VW412.

This trans has very few parts available. Differential side bearings, races and seals.....no problem. Same as 091.
However.....the pinion shaft bearings.....are either no longer available.....or are just very limited run. What I can find is fairly pricey (about $65 each) but not prohibitive. The pinion bearing races are easy t find as they fit more than one bearing.

The bearings in question: the factory typically used SKF 331457 with the associated SKF race. Typically if the trans has been worked on through the 80s you find Timken M86648 with the M86610 race......which work just fine. Excellent quality bearings.

The question: what I can typically find shopping for bearings out there are SKF bearings and no SKF races....only Timken races.

In the real world for items like wheel bearings I have mixed brands of cups and cones with little real issue but those were items that saw 30-50k miles tops before needing replacement for one reason or another....usually just from contamination or upgrade disassembly of adjacent parts.

What are your feelings about mixing brands on critical components like ring and pinion bearings?

Thanks! Ray

[Marc]

"International standards only mandate that the same part numbers have the same basic
outside diameter, bore and width and cup angle, allowing the internal geometries and characteristics to vary from manufacturer to manufacturer."
http://www.timken.com/en-us/solutions/a ... ol7No2.pdf

I'd expect you to be able to get away with it, though, provided you inspect them closely for discrepancies...the angle match would be the biggest concern, perhaps that could be checked with white lead.

[raygreenwood]

"International standards only mandate that the same part numbers have the same basic
outside diameter, bore and width and cup angle, allowing the internal geometries and characteristics to vary from manufacturer to manufacturer."
http://www.timken.com/en-us/solutions/a ... ol7No2.pdf

I'd expect you to be able to get away with it, though, provided you inspect them closely for discrepancies...the angle match would be the biggest concern, perhaps that could be checked with white lead.

Yes.....that was my exact worry. I have " gotten away with it" on wheel bearings. But years ago.....when rear wheel bearings for vw 412 which had few other applications...and were generally not available in Timken and only made by SKF and FAG. ....during the vacation month of,August.....as line fillers.....I started using mix and match new parts for cup and cone. Those rear wheel roller bearings are large and highly loaded....larger by a good deal than the differential bearings.

I noticed a slightly shorter life when i mixed and matched. I never really knew if it was a dimensional difference in the parts....or one part was just lower quality.

Not willing to risk it on a pinion bearing I can get Timken cups and cones and will just skip the SKF unless I can get complete cup and cone set.

Thanks Marc!
Ray