It's a Fast Load triple axle trailer rated at 18k lbs. What size wheel bearing do I need as the old one is pretty much unidentifiable.

what brand axle first then go to mfg site that should help

remove 1 of the other wheels. Sounds like a good time to go thru all 6

18k I imagine is 3 8 lug axles. Look at redneck trailer parts .com or just google 8 lug dexter axle

and chances are the rest of them are over heated so you might want to buy 6 inner and outter bearings and seals..make sure they are timkin..

*Timken

http://www.timken.com/en-us/Pages/Home.aspx

Made in the USA and 1000% better than the Chinese bearings that come in just about everything, and usually sold retail.

18K rated, so 6K axles?.

Last time I checked, Timken bearings, which are the best, were outrageous.

If a 6K axle with 1 3/4" x 1 1/4" tapered spindle, try this. Inner bearing (25580) and outer bearing (67048), You should be able to buy a complete kit (bearings, races, cotter pin, nut and washer) for $15-$20. If you have a Northern Tool or any trailer repair shop close, they should have what you need.

Timken bearings are WORTH the extra money.
1) American made
2) Better steel
3) 1/3 more bearings +/-.

OSO member Doc Holiday did all of the comparisons here on OSO many years ago. I learned a lot; and I go out of my way to obtain Timken bearings. Their axle seals are also far superior. I've been towing for close to 20 years, and I've never had a bearing failure. I must be doing something right (as I knock on wood).

I'll gladly pay the extra money vs. sitting on the side of road, putting me, my family/passengers, my rig, at risk; and getting dirty as a ditch digger while I really want to be either where I'm going; or out on the water.

Last Timken bearing I bought recently, was stamped ''Made in CHINA''. It was not a trailer bearing though.

https://www.youtube.com/watch?v=mEB7WbTTlu4 Chinese bearing in a Timken box? Stranger things have happened.