Oregon allows you to use any DOT truck scale when it is not open for truck enforcement.
If CA does not allow that, you can find a private scale here: http://catscale.com/
Landscape materials lots always have a scale too. Sometime they charge, sometimes they don't. Our local landfill also does free RV weighs.
The cost of your repairs makes me think they did much more that just a seal. At the very least, new bearings and I wouldn't be surprised if they had to replace the axle shaft on the leaky side. You caught your axle problem early. If you kept driving much more, you probably would have lost the entire hub from your axle shaft. Semi-float axles do not have a pretty failure mode.