Running in water - A lot of RTR's - including the Arrmas - are Water Resistant. Yes, I know Arrma and others say Water Proof, but that is not true. My fishing buddies have a saying - water will destroy anything that is not water, or fish. 
You can't stop water, you can only slow it down. Running an RC in wet conditions is fun, but you have to expect to re-lube the car. Wheel bearings, CV/U joints, ball cups especially.
For cleaning bearings, take the side shields off first. for rubber shielded, use the point of an Exacto to carefully pry it out. For a metal shielded bearing, there is a small snap ring around the outer edge. Find the gap in the ring, start there to pop it out, then the metal shield will,fall out. Once the shields are off, I use brake/carb cleaner to blast out all grit and old oils (do this outdoors!!). Dry on a paper towel, then check that they spin free. Re-blast with cleaner if needed. When they are clean and dry - I relube with reel oil, or a bike 'wet' lube. Also a lube like Tri-flow is good. If you can't find a good lube, make your own, mixing 2:1 mineral spirits with auto motor oil. DO NOT USE WD-40!* Put one or two drops only on each bearing. Spin them. Add one more drop, then dab with a paper towel to remove extra. Put the shields back on, add one more drop of oil, spin them, wipe them, and they are ready to install.
While I agree bearings are kind of disposable, a little bit of care will extend their life by 3x-5x. When it comes time to replace them, I've use Fast Eddies, Avid, and the cheap Amain brand bearings. All were good - better that the RTR bearings.
*WD40 is a water displacing lube. It also does a great job of washing out oils. Also, WD40 WILL evaporate, leaving your bearings un-protected. Then, they quickly die. If you use WD40, follow up a day later with a proper non-evaporating oil, or you WILL destroy bearings.
Jerry
You can't stop water, you can only slow it down. Running an RC in wet conditions is fun, but you have to expect to re-lube the car. Wheel bearings, CV/U joints, ball cups especially.How to clean RC Bearings
For cleaning bearings, take the side shields off first. for rubber shielded, use the point of an Exacto to carefully pry it out. For a metal shielded bearing, there is a small snap ring around the outer edge. Find the gap in the ring, start there to pop it out, then the metal shield will,fall out. Once the shields are off, I use brake/carb cleaner to blast out all grit and old oils (do this outdoors!!). Dry on a paper towel, then check that they spin free. Re-blast with cleaner if needed. When they are clean and dry - I relube with reel oil, or a bike 'wet' lube. Also a lube like Tri-flow is good. If you can't find a good lube, make your own, mixing 2:1 mineral spirits with auto motor oil. DO NOT USE WD-40!* Put one or two drops only on each bearing. Spin them. Add one more drop, then dab with a paper towel to remove extra. Put the shields back on, add one more drop of oil, spin them, wipe them, and they are ready to install.
While I agree bearings are kind of disposable, a little bit of care will extend their life by 3x-5x. When it comes time to replace them, I've use Fast Eddies, Avid, and the cheap Amain brand bearings. All were good - better that the RTR bearings.
*WD40 is a water displacing lube. It also does a great job of washing out oils. Also, WD40 WILL evaporate, leaving your bearings un-protected. Then, they quickly die. If you use WD40, follow up a day later with a proper non-evaporating oil, or you WILL destroy bearings.
Jerry
