the bearings are sold many ways even in 4 part kits, (1 bearing 2 seals and 1 collar)
so the bearing lip seal is missing 1RS bearing, 1 lip seal not 2 RS 2 lip seal bearings
the bearings are sold in vast ways now, (not suzuki.com they are discontinued) REAR AXLES parts.
8 bearing seal types. (none = open and 7 seal types) (seen at Timken)
china junk bearings a.k.a. NO BRAND. (knockoffs etc)
there is no Koyo Ecatalog now, to see suzuki parts. look up.
Timken sells all 8 bearing types (1 size) for here. 2RS is 2 lip seals, there are dust seal types too and are dead wrong for this car.
https://www.summitracing.com/parts/tmk-5...l/sidekick
as you can see the Timken bearing 511004 ,is double lip sealed.
the grease seen on the balls (eyeballs sees grease 1RS or open bearings that means the grease is junk packing grease. (I use paint thinner to clean that all off)
the bearing may have an offset, did you check that? (center of bearing hub offset)
the inward seal sure can be missing, and must be fully greased by hand, after cleaning the balls of all packing grease
as you can see if the inboard axle seal fails, the new bearing works like the old open bearing GL5 lubed SAMURAI
that is my guess, the bearing can now default to GL5 lub , method
GL5 is Gear lube rear axle .
Timken Wheel Bearings 511004
I am not the car or bearing designer, just a messenger /tech
bearings are complex, for sure the flooding of china junk parts, here, finding quality parts can be super hard today.
if the RTV steps are followed in the manual, the open bearings and top branded grease work just fine.
in fact this way even allows more grease to be there, (may be better IDK)
all new seals is best if doing this job only once.
The car was made in 1990( after july 1989) and used IWATA made japan axle full assemblies for track kicks and sunrunners. and the vitara's world wide.
and what they used then i have no clue.
Koyo is a great guess,but no part numbers ever posted here of the old bearings, (stamp'ings)
as you can see the Timken bearing 511004 ,is double lip sealed.
the success will be, using the best grease. Mobile 1,or aircraft grease as I show here
https://fixkick.com/fw-bearings#Grease-extreme
see the ASTM spec there on high temp grease (and low)
??? cheap grease is cheaper.