another needle bearing question

[ldj]

I pulled a gear and shaft from caged needle bearings. A couple needles fell out. I put them back with lots of grease holding them and put gear and shaft back. It turns real good with no drag at all. Will it be ok to use this bearing? I would think yes since all u joints I have saw have needles that aren't caged.

 

[Chris (WA)]

Unless it is in a criticl installation, use or saftey wise, I would do as you have and run it. Most applications using needle bearings do not require the bearing to rotate at high speeds or heat conditions so they should last.

 

[old]

If your talking the type of bearing that has the rack sort of thing that holds each bearing in place and a little bit away from the others with out being in that rack sooner or later it will cause you problems and they need to be held but the rack they had been in. BTDT and found out that sooner or later they will bind and then lock up or at least they did when I tried it

 

[M-MAN]

It will last a little while but the needles are going to satrt leaning and wear fairly quickly then. A U joint is the same way. As long as the needles don't have enough room to lean sideway's they last but leave out one needle so the rest can lean and it go's downhill pretty quick.

 

[NCWayne]

As Chris said if it's not in a critical and/or an application running at a high speed, etc then you should have no problems with it. I run into the same thing when doing "field repairs" to the rotation gearboxes on a customers rock drills. In fact there is one still out there running after close to a year that is actually missing a needle or two. The customer took the thing apart trying to save the cost of me doing it, lost them in the dirt, and didn't have the $500+ needed to replace it with a new one at the time. That aside I've had brand new bearings drop the needles out of them before so the fact that a few fell from their cage doesn't necessarily mean that the bearing is worn out, just that is has enough wear to allow them to drop out easily. So, unless it's running in a high speed, critical application that would cause alot of problems when the bearing finally goes out, or in a place where the labor cost to replace it later would be way more than the cost of a new bearing and doing it now, I'd say run it and don't worry about it.

 

[Bob]

What will a new bearing cost compared to the extra labor, downtime, and damaged part(s) if the bearing fails?

I have had the needle bearings in front hubs of 4X4 trucks do that (fall apart), and if you look INSIDE the steel outer ring, often you will see pitting or spalling.

Did you look inside your's while it was apart and cleaned up before smearing the grease inside and replacing the needles?

 

[ldj]

Thanks for input.

It isn't high speed. I didn't clean it all and inspect, however I did clean the needles that came out and they look ok best I can tell. The needles aren't held in their own place on the cage ie. they can all move around the cage. It isn't the cost of bearings as much as I want to put it together tonight and have it working in the morning before I could even get bearings.

 

[trucker 40]

I agree.Ive put them back together and they will run.I even have put a roller bearing back together that all the rollers fell out of a brand new bearing.You just make sure you put them the right way,might have to look at a new one to tell,and put it back together.Ive put needle bearings back together in the front of transmissions and a lot of things Ive worked on.I cant remember ever having any trouble with one that was put back together.Now if you are missing needles,more than 1 or 2,you are going to have trouble probably.

 

[trucker 40]

In a case like that,if you take the cage out,and put another needle or 2 in,like out of your old bearing if there are any good ones,and with everything clean you have a little clearance so they arent touching at the very end,and put grease on them,it will probably run without the case.Thats if you can get it together with an extra one or 2 in there.Thats how the input shaft of a transmission is on a lot of transmissions and they run without the cage for a long time.Sometimes you might not get it together so in a case like that you are better off with the cage.All that cage does is hold them so you can get it together and so grease can get in between them.If they are tight together when you try and put a needle or 2 in,it might not work,and might not get the shaft in it anyway.

 

[Bob]

"missing needles,more than 1 or 2,you are going to have trouble probably"

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