Motorcycle Center Jack - Take care of your bearings

More of a PSA than anything: I have a Liftmaster center jack that I've enjoyed using for the last year. It's pretty to quick to go up or down and holds the bike well when I need to do a tire change or other maintenance on the lift. About 6 weeks ago I found a ball bearing on the floor (always fun), but found that it matched the size that was in my rolling shop chair (which has had a hard life). Last week when I was working on a friends bike, I had a heck of a time trying to use the center jack and finally noticed that 80% of the bearings were gone, I broke one end of the bearing retainer, and the bearing cage was crushed. Dumb me didn't think to take a moment and see if the bearings were actually greased from the factory. A new, higher quality 51102 thrust bearing was secured from a bearing supplier for ~$15, greased, and installed. The jack works great now. I suspect that most of these lifts are made in the same factory, so hopefully this will save someone from having to go through an ordeal.

I have a similar jack. I often used a drill to raise and lower the thing. Yes, the OEM bearing is junk but the problem occurs when you lower the jack down all the way and then some. This will back the nut and washer away from the bearing pieces and the balls will fall out. I suspect almost all these inexpensive jacks are like this. I attached a warning label ("do not lower beyond the stop") to help me remember.

Ed_Jorgensen said:

I have a similar jack. I often used a drill to raise and lower the thing. Yes, the OEM bearing is junk but the problem occurs when you lower the jack down all the way and then some. This will back the nut and washer away from the bearing pieces and the balls will fall out. I suspect almost all these inexpensive jacks are like this. I attached a warning label ("do not lower beyond the stop") to help me remember.

Click to expand...

Interesting - mine has a shaft collar to prevent that very thing.

There is almost nothing that can't be made cheaper and less reliable if a person/company puts their mind to it.

Good info
Looks like a great “on the lift” jack.
OM

I have the same jack, different brand, probably out of the same China plant.

A couple years ago I was changing the tire on my Harley and the screw galled up. I forced it, it broke! Luckily i was nearly done so the bike dropped down onto the tire.

My one caution on these jacke is to lube the screw! I smear wheel bearing grease on mine.

I actually found a piece of grade 5 5/8" UNC threaded rod and repaired my jack. I also replaced the bearing with a better quality, enclosed unit, nothing to fall apart.

I have had a couple people give me a hard time about fixing it. Possibly the threaded rod is not strong enough, but as easy as the original threaded rod snapped i question the quality and believe the rod I used is better. Also, I went with a standard 5/8" UNC rod. Some have commented that it should be acme threads, again the original rod was very poor quality and the threads were very poor.