this from Vintage Airstream:Wheels & Axles - Vintage Airstream
Another area that you need to be aware of are the different grease seals available. Many RV outlets have a simple single lip seal that will fit in Airstream axles. Airstream does not use nor do they recommend the use of single lip seals. Their recommendation is to use double lip seals only. They may be a little harder to find is a small price to pay for the added security.
The original P/N was a National 291148 felt seal and 292100 in the 60s Henschen axle. The 292100s are available from OasisRV
. The TCM 21325TB
"Not all who are laundering are washed" say Bill & Heidi
'78 Excella 500,"The Silver Pullit". vacuum over hydraulic disc brakes, center bath, rear twin. '67 Travelall 1200 B 4X4 WBCCI 3737