All you need is the part number off the roller bearing and the race. Any auto store in town be able to provide the proper bearing. You can also measure the inner and outer bearing bore diameter. Tahoe trailer is like saying I have a 20xx Chevy -- what is the part number for the spark plugs. Chevy has a gazillion engines and the plugs are not the same for all of them. Back to the bearings -- if you look at the tag on the axle it will indicate the load capacity. A 3500# axle will generally have a 1-1/16 bore outer bearing and a 1-3/8 bore inner bearing. Again, any big box store like Dicks Sporting Goods, Tractor Supply, Farm & Fleet and yes -- right here on iBoats will have them.