I have to admit that I have been against putting any lubrication on bearings in traveler cars. My reasoning has been that the traveler car bearings fail because they slide and get tiny flat spots on them (and this is true). Adding lubricant to the bearings will tend to make them slide more easily (and attract dust dirt) ... ergo, lubrication can make your bearings suffer a shorter life.
I caught Bret monkeying around with my traveler car on the back of our 20 (that I was planning to replace the bearings in) and he said he was putting that lube on there that Mike with
Layline had brought in the Layline parts trailer
(see, that's how it's done!). I was skeptical but didn't really give it much thought because I was going to replace the bearings anyway.
HOLY GREAT MOTHER OF ALL THAT IS HOLY!!.....that stuff works extremely well and will be in my tool box from now on. I've never had a traveler car - even with NEW bearings - work that well.