Wheel bearings

Post by **edjones** » Fri Jun 13, 2003 9:04 pm

Part of servicing a minor talks about repacking the bearings with grease. Excuse my ignorance, but what exactly does this mean and how do you go about it?
Ed

Post by **Willie** » Sat Jun 14, 2003 4:15 pm

You pack the FRONT wheel bearings only with high melting point
grease. If you look at the centre of the front hubs you will see
a cap, this can be prised off with a screwdriver to expose the
nut and split pin which holds it all together. You can also see the
outer bearing. Fish out as much of the old grease as you can and
refill the area with the new grease,and the cap,and then tap it back
in position. Thats it!

Post by **edjones** » Sun Jun 15, 2003 4:40 pm

Thanks, Willie!
Ed

Post by **les** » Mon Jun 16, 2003 9:38 pm

Have I read your post wrong Willie? I dont think the cap should hold any grease.

Post by **Willie** » Mon Jun 16, 2003 10:51 pm

No les I have always packed the caps with grease?? I have never
had trouble with leakage past the oil seal either.

Post by **Cam** » Mon Jun 16, 2003 11:11 pm

Yes, I have always packed them with grease (with no problems) so that when you put the cap back on, a little bit squirts out of the tiny hole in the middle.

Post by **Chris Morley** » Tue Jun 17, 2003 1:08 am

The cap's there to keep the dirt out and the grease in. If you prise yours off Les you should find grease. If not you will need new bearings.....

Post by **fweddy** » Tue Jun 17, 2003 9:35 pm

What is the idea of filling the whole cap with grease as opposed to well packing the bearings alone? — Reserve? Heatsink?

Post by **Willie** » Tue Jun 17, 2003 9:49 pm

Well I have always accepted that you cannot properly grease
the bearings assembly when you fit it so the final cap full at
the end makes sure that there is sufficient. There is a small
hole in the cap anyway which allows excess grease to exit.

Post by **les** » Tue Jun 17, 2003 10:48 pm

Interesting comments, but I still disagree, How can grease from the cap find its way back to the bearing, I suggest that any grease found in the cap got there from an over packed hub! But lets not fall out over our opinions!

Post by **Willie** » Tue Jun 17, 2003 10:57 pm

Come on Les, the washer allows grease to reach the outer
bearing, it passes through it ,around the spacer and reaches the
inner bearing.........unless you have been fitting sealed bearings??

Post by **Kevin** » Wed Jun 18, 2003 12:46 pm

Willie is correct again, also if your theory was correct Les why would the grease stop at the cap, and not just continue out of the small hole and make a nice mess.

Post by **Jerry** » Fri Jun 20, 2003 9:49 pm

I was taught to put a wad of grease on the palm of one hand. Then, holding the bearings with the other hand, roll the bearings with a little force into the grease, forcing grease into the bearings. Continue turning the bearings in your hand until all the bearings have had grease forced into the area between the bearings and the outer race. This way grease is packed into the bearing area without having to rely on grease migrating into the bearings. I also apply a dollop of grease on the bearings after I have reinstalled them.

Jerry

Post by **grainger** » Sat Jun 21, 2003 1:58 am

it says on the tub of grease 'DO NOT OVERPACK BEARINGS' how packed is overpacked ? i had a bearing that was making some noise, so i put some grease in it but then when i took it to the garage they said the bearing was nackered and had to be replaced. perhaps i had done it by putting too much grease in, but it was probably already done in when i regreased it.

cheers
grainger

Post by **Cam** » Sat Jun 21, 2003 11:01 am

Yeah, it sounds like it was already knackered before you got to it.

I have always taken that to mean - don't completely remove all the air by forcing grease into every last air pocket.

Although I said that I 'packed' the bearings above, I just meant I used a lot of grease, and not forced grease in everywhere.

after greasing the bearings by hand (as well as the stub axle), after reassembly and tightening, I smear some grease around the outer race face and the nut and split-pin. I also then put some grease in the grease cap but I don't completely fill the hub and cap to capacity, I always leave a bit of air in there.

Would be interesting to know what the exact definition of 'overpacking' is though.

Post by **Willie** » Sat Jun 21, 2003 8:11 pm

I have read articles which stated that if bearings are too tightly
packed with grease it can produce 'frothing' which results in
inadequately lubricated areas!! I do not subscribe to that
theory, it seems to me that the small hole in the bearing cap
will alleviate any excess grease pressure.

Post by **Cam** » Sat Jun 21, 2003 11:20 pm

the small hole in the bearing cap will alleviate any excess grease pressure

Yes, I would agree with that. There cannot be too much pressure as air/grease can easily flow through each of the races, and like you say, out of the small hole in the cap.

Post by **les** » Sat Jun 21, 2003 11:28 pm

So far it seems that the grease/air, if moving at all, is only tending to go one way, that is towards the cap and out of the hole,and you know what I'm going to say next!

Post by **Gareth** » Sun Jun 22, 2003 9:06 am

Les, every workshop manual I have (and trust me, I need 'em!

) says that the bearings should be packed with grease when fitted.

Then, as a maintenance task, the amount of grease in the cap should be checked, and periodically cleaned out and replenished.

I think you're going to lose this one, mate! Hehehe

Post by **les** » Sun Jun 22, 2003 9:28 pm

Well ok, I've been wrong before and I expect I'll be wrong again!HoHoHo, 'till the next time then.