Continuous Trailer Bearing Failures On Single Wheel  

In July 2018 I bought a fifth wheel trailer. In the short amount of time that Ive had this trailer Ive had two major wheel bearing failures on the same wheel. My wife and I are planning a 5000 mile trip this spring and, frankly, I dont trust the wheel bearings. I am not an engineer and dont understand how the engineers felt the component weight ratings were adequate for the unit. According to the Weight Sticker: GVWR: 9995 lb GAWR each axle: 4400 lb. UVW: 8614 lb. Max Cargo 1321 lb. Hitch weight 1516 lb. From RVUSA.com So if my figures are correct: 1516 lb. Goes on the hitch and 8479 lb 9995 - 1516goes on the wheels. So if I had two 4400 lb axles, they would be adequate for the maximum weight. Except Ive always heard that the maximum weight was always limited by the strength of the weakest component. My hub and thus the bearings seem to be rated at 3500 lb. Hub part number: RVD-H 65535 Now I read this, from what I have found on the internet, as 6 6 bolt 55 5.5” inches between bolts 35 3500 lb So how can my axles be rated at 4400 lb when my bearings are rated at 3500 lb? And if my wheels have to support 8479 lb and the bearings are rated at 7000 lb. 3500 X 2 isnt the unit 1479 lb. overweight on the bearings? I am sure that I am wrong on my figures and dont understand how the engineers came up with the components they did, but at the same time, after having two catastrophic failures and seeing that they didnt engineer any or much leeway into the suspension, I want a change. That was my problem, heres my solution, I hope. I want to replace my entire axle with the next size up, that being a 5200 lb. Axle. My current problem axle has the following information on its sticker: LCI35-SB-86.5-68.5-NOSP-OS-L-655-7278-30PT-3”-GAWR 4400# If correct, I read this as 86.5” Hub Face and a 68.5” Spring Center with a 3” Tube. I have not verified the figures by actual measurements. I will do so before ordering, if I can dig it out of the snow. It looks to me like I could piece together a similar axle by buying: 1 Dexter Trailer Axle Beam with E-Z Lube Spindles - 86-1/2inch Long - 5,200 lbs Item # 8327816 Has an 86.5” hub face but a 71.5” spring center so I would have to buy two 2 Spring Seats for Typical 5,200-lb to 7,200-lb, Round Trailer Axles with 3inch Diameter Item # TRSS300 and have the old spring seats cut off and the new spring seats welded on. 3 It then appears that I can add two brake assemblies: AKEBRK-7L-SA and AKEBRK-7R-SA 4 And two hubs: 8-201-9UC3-EZ Concerns: It looks to me like this would work but you guys are the experts. Tell me if something doesnt look right. I would keep the front axle as is. I know I would have to buy dissimilar parts since I would have a 10” brake in front and a 12” brake in the rear, with different bearings, but Ive already spent $1700 to get the unit home and Im tired of spending money on the wheel bearings. Would the two different size brakes cause problems with the brake controller? Thanks for your help.

asked by: Jerry