SeaSense Roller Shaft with Grease Fitting - Heavy Duty Marine Bearing for Boat Trailers & Docks - Perfect for Smooth Rolling & Long-Lasting Performance

If you deal with salt water, this shaft keeps the rust from freezing up the roller!Good idea greasable only goes a few inches along end of shaft anything helpsBeing able to grease the roller shafts on your trailer is a great idea. However, the dispersion holes are too close to the ends of the shaft. The grease holes should have been placed deeper on the shaft. If the shafts had one hole more further down the shaft from each end it would be a great product. I ordered 3 new rollers to replace all the rollers on my trailer. I also ordered 3 of these shafts. All 3 of the shafts returned and now using solid shafts for now. They are well made and the clips on the ends are much better than what comes with the solid ones. I hope this idea gets improved, then I will replace the solid shafts next year.I like the idea.I installed this on my boat this spring.I am sure the grease fitting concept is working as designed.I used a plain solid axle for 25 years without a problem.I am not sure that this was really needed.Shaft itself is ok. However, the holes for transfer of grease are only an inch from each end, and do not even reach inside a 12" roller on both ends. Some have spoken of redrilling new holes, but unless they also extend the hole that the grease zert is mounted in, the grease will not reach past where the holes are already drilled.This style shaft is the only way to go. I've only been getting a few years out of plain hard steel shaft before everything rust solid and rollers won't turn. Anticipating more bang for the buck with these by just being able to keep them lubed. They look to be well built and time will be the telling story. So far so good.I wish I could put six stars what a great idea having the grease fittings and fits perfect for your 8" roller has two setting to put the pins in incase you need it a bit longer or shorterPackage was damaged. When opened, could not find one of the C clips that go on the ends of the shaft. Found it under a fold in the Amazon box. The C clip was bent, but was able to straighten it and use it.Dont order these shafts that need keel roller end caps. Unless you plan on using yates rollers. Seasense discontinued the keel roller end caps. I emailed them about this because I've been having such trouble getting them and was told by them directly. So I will be returning all the stuff I bought from them as it's now useless. I will be buying a complete assembly instead of trying to piece together a 12" centering roller.At first I though I wish there was more holes for the grease, but realized there are inserts on the roller and the middle is hollow so two holes are enough. Adjustment on the length is based on which slot you put the c-clips in.very poor description there fore the sizes didn't really fit the job, or the roller so I had to have the roller shaft cut and welded to fit