so... you think you're greasing your bearings

[brushcutter]

It's been raining here so I thought I would take that as an opportunity to do a little maintenance, since I couldn't ride anyhow. Iv'e been noticing that my 950 was leaking for some time now. So one of the last rides that I took I left the floorboards at home and went to the creek to see if I could find the source. Now keep in mind that I had already tried the old fill 'er up trick and although it did seep from all but one axle, the fill rate while riding seemed roughly equal to the fill rate of the hose going full open into the tub. So upon driving into the creek I killed the engine (don't worry I wasn't in deep enough to float) and listened to the sound of trickling water. Yup you read right I could actually HEAR it pouring into the tub. So I knew I had a problem.

Fast forward to what I found on teardown. RTV to hdpe BAD! reuse old rubber gaskets BAD! water in bearings BAD! Loose inner bearing setscrews BAD! no loctite on outer flange bolts BAD!

Decided to do a little test : It has been my experience that most bearings can be repacked with grease if you are careful to not damage the seals upon disassembly. All my outer bearngs had some spreading in the seals. So I figured what the heck and popped the little metal ring off the outside only to find that it was only that, a metal ring to protect the actual seal which is no different from your average sealed bearing seal- rubber ring around the inner and outer circumference of a thin ring of metal , which resembles a really thin washer. So I cleaned the crud out with solvent and compressed air and packed it ful of lucas red and tacky and put it all back together.

Now the real surprise was this: I grease my machine after every weekend's riding. Usually on Sunday or Monday evening OK I'll admit it I have even been known to skip it until Friday morning before I head to the swamp for my solo trail work ride. But what I'm saying is that the 950 gets greased every week, up on blocks, tires off, in gear, with the axles rolling to be sure the grease goes where it is needed. WRONG! I must state that I was QUITE dismayed to see VERY little grease in the bearings when I disassembled them. But there did not seem to be much mud in them either which also came as a surprise.

From now on the torque wrench gets used and loctite goes on everything!

Did I over grease them and blow the seals? Don't think so, remember The loose setscrews and flange bolts I mentioned well those combined together with the normal stresses of riding conspired to loosen the seals at the bearings which left to themselves would have had me buying new bearings pretty soon I think. So, if you think that you are greasing your bearings enough then you might want to think about all this and pull one from time to time just to be sure.

Oh yeah and those rubber gaskets, well they are gonna go for a ride on the garbage truck soon. Seems like Auto Zone sells some stuff called Ribbon Sealer It's used to replace auto glass and has an ingredient list that is very similar to the 3M strip caulk that Recreatives sends with their bearings as a replacement for the junky rubber gaskets. I will let you all know as to how all this works. Think I might even TRY to blow A seal on one of the bearings just to see how much it takes. I mean since Iv'e got it torn down anyway and it's only a matter of pushing the seals back in....

[kgrant]

Where was the grease going? Between the flanges/body instead of into the bearing?

[brushcutter]

Yup, it seems as though it was coming out on the inside from between the flange and bearing. So when reassembling I am marking the holes on the visible edge of the outer race so they can be alligned with the zerk. Seems that the flanges cover the holes at least partially and therefore prevent the grease from getting to where it needs to go. I have toyed with the idea of leaving the metal cover off the inside when reassembling which would allow some protection but would also allow me to remove the inner seal to see if grease is going in as I want.

Another point is that of "what happens to the old grease?" Having the ability to remove the inner seal would then give the old grease an escape, if you will, and allow clean lube to force it's way into the bearing and the old out to be wiped away before installing the seal again.And by still having the inner seal in place the bearing would remain protected (as much as it is now)from dirt and water,which are getting in anyhow. The removal/grease check would not have to be done but bi-monthly or so is my thinking but you would be able to tell almost at a glance if there was trouble.

I'll just have to stick my neck out and try all this, because the way I see it, if things had continued as they were then I would likely been buying new bearings (and still might) with less than 1 year on the ones on the machine now. So what do I have to loose?

[Mike]

I do the same thing that you just mentioned. I take a sharpie and mark the outside of the bearing with a line pointing to where the hole is. It seems that is your best bet for being able to get grease in there.

Another thing that I have noticed. If you replace the flanges when you replace the bearings, they provide a much better seal than old flanges. I guess the torque from the 3 or 4 bolts on the flanges can warp the flanges slightly. I have done a machine with all new flanges and one where I reused the flanges and it made a big difference.

The biggest thing that helped mine though is getting ride of any gaskets and just using silicone instead. Apply a liberal amount on the flange without the zerk making sure that you don't get any silicone where the groove of the bearing will be. Place the bearing in the flange and then put the outer flange on.

Here is the kicker though. Just slightly tighten them and allow them to dry for 24 hours. The next day torque them to the specifications for your flanges, usually 30-35 ft.-lbs. I have used this method on two occasions and had great luck. When I didn't do this I had similar results as you. Grease coming out between the flanges and everywhere else that it wasn't supposed to.

Both times that I used this method The grease comes out of the inner race where it should. I don't know that leaving the flanges just barely tight overnight helps but in my mind that allows the silicon to form a seal and then when you tighten it down further you are tightening against the seal instead of just squishing the silicone out.

Just some random observances from my amateur experiences.

[brushcutter]

Mike are you talking about between the recessed area of the flange, between the flange and the bearing?

[kgrant]

I'm in the process of replacing the bearings on my Hustler. I'm doing similar as Mike is doing. I am putting a thin layer in between the flanges, and a thin layer on the outer race where it will contact the flange. I'm using Permatex Right Stuff. I'm being careful not to put too much in there so it won't plug the grease ports in the race. I'm not doing a partial tighten, then cure. I'm tightening them fully the first time.

My plan is to give the grease only one path to go, through the bearing!

[Mike]

Mike are you talking about between the recessed area of the flange, between the flange and the bearing?

I'm bad at describing things so let me link to a picture. This is from the Max II axle and bearing replacement how-to article. I no longer use the paper gasket though.

[brushcutter]

Yeah Mike That is what I did, run a bead around the flange before assembly. That seemed to seal the 2 halves together real good. When I tore mine down I found no place where the RTV had lost its grip and the flanges had to be sliced apart with a putty knife! I have decided to remove the thin metal protector from the inside of the right front bearing but slide it on the axle so it can be replaced after testing. My plan is to ride for a couple hours, get it up on blocks, then watch it as I give it a shot of grease. Then pull the rubber inner seal and check for contamination (hopefully none) then give it a shot of grease to see what the grease/contaminates (if any) does at that time. By doing this with the rt front axle, I can watch the bearing while I ride to see what is going on. The front axles are also easily accessed for repair, if necessary.

Kgrant, keep in mind that a grease gun can have an output up to several THOUSAND PSI dependant on the gun.On dozers the tracks are tightened by loosening a few bolts and using a greasegun to tension them. So the grease WILL go somewhere!LOL I hope to have mine up and going again by this weekend, so if you aren't in a great big hurry, give me some time and I will let you know how this all turns out-gladly. Check Auto Zone for ribbon sealer to put between the inner flanges and the tub it is very similar to the strip caulk that R I uses on their flanges and it only costs a few bucks for 15 feet.How cool is that!

Among and whilst I am doing all this axle research I have also pulled the tranny to drain the fluid. It's just easier that way and I KNOW that ALL the old fluid is getting drained. And since I have all the axles out anyway I will be going to The 40 tooth main drive sprockets that I traded from Dave.
Happy riding Gregg

[kgrant]

The grease is going to take the path of least resistance, wether the holes are lined up or not. The outer race doesn't create a perfectly tight seal with the flange, so that's where the grease is going to go if you don't seal it.

[brushcutter]

Well guys the ribbon sealer worked great. There is still a tiny amount of water coming through the bearings but all combined only adds up to a trickle. I can live with that. Before the reseal work I would have to run my pump regularly and at times constantly. Now I can run through all of my trails and only pump a gallon or so afterwards.