Front Wheel Bearing Modification - One Good Out Of Two Bad!

[tolsen]

@ Edwin52.

 

Calliper pins and bores really should be cleaned and then greased using a special non mineral grease that does not make rubber swell.  I use a special silicone grease which is approved for food processing machinery.  May post details of this special grease one fine day.

 

Remove brake pads and try spinning wheel without them.  Grip wheel 6 and 12 o'clock and feel for play.  No worries if you cannot identify the bearing noise.  It will soon become nearly unbarable so easier to detect where from later.

[Smart42]

Question: looking at Tolsen's photos of the bearing I understand there is an outer and inner bearing each with their own race. I assume the rear is the same?

This is similar to those found on ATVs, like my Arctic Cat. To grease those bearings you can now get a bearing greaser, see picture below. The tool injects the grease between the two races. The pressure is enough to push the races slightly apart allowing the grease to flow in to the bearings. This works slick in my ATV, so I wonder if it would work for the Smart too? Would make greasing the bearings an easy maintenance job. Does anyone have measurements for the inner diameter of the bearings and the depth to the middle between the races?

 

 

[MikeT]

If you could find a needle greaser that would do the trick too and ne good for steering swivels as well.

Edited March 6, 2023 by MikeT

[Willys]

The next thing would be to turn down a plug to cover the grease nipple made from some hard plastic.

The whole thing would be easy enough to make if you owned a lathe.....but, how many smart owners would purchase them..?

That is IF this worked on our cars...?  Hmm....maybe something to look into seeing as I can easily get at this area at the moment....?


Anyone forget about the hub or axle shaft bolts...?    This would mean adapting the actual hub to something similar, which isn't so easy, but doable IF you thought it worth while..?

Edited March 6, 2023 by Willys

[tolsen]

On 06/03/2023 at 1:09 AM, Smart42 said:

Question: looking at Tolsen's photos of the bearing I understand there is an outer and inner bearing each with their own race. I assume the rear is the same?

This is similar to those found on ATVs, like my Arctic Cat. To grease those bearings you can now get a bearing greaser, see picture below. The tool injects the grease between the two races. The pressure is enough to push the races slightly apart allowing the grease to flow in to the bearings. This works slick in my ATV, so I wonder if it would work for the Smart too? Would make greasing the bearings an easy maintenance job. Does anyone have measurements for the inner diameter of the bearings and the depth to the middle between the races?

 

 

 

[tolsen]

Front bearing is easily greased. Simply overpack grease into bearing having first removed dust cap. 
Grease will then flow into bearing and out of its inboard seal as bearing and grease warms up. 
 

The only way to inject grease into rear bearings is by bearing dismantling to make a grease path and fitting a grease nipple in centre bolt. 
 

My wheel bearings are still good. Must be nearly 12 years now since I did this mod. 

[Smart42]

On 3/7/2023 at 3:56 PM, tolsen said:

The only way to inject grease into rear bearings is by bearing dismantling to make a grease path and fitting a grease nipple in centre bolt. 

 

Looking at the images you posted in your excellent thread about the rear bearings: why not drill a hole and fit a grease fitting in the center of the hub? It would inject the grease between the 2 ball bearings and negates the need to grind a path in the race or drill the bolt. For access it would require removing the brake drum, but you only need to grease them once a year or less.

 

[Willys]

This is the obvious answer, the problem is, drilling a hole through the bearing race....something most standard drill bits will not even look at....Even good drill bits laugh at this possibility.  OR I would have done this years ago.....
The answer to this is to drill bearing in a mill using very good bits/cutters before installing into the hub. The you should disassemble bearing to shamfer the inner surface of the race where the rollers will ride or that rough surface will lessen the life of the bearing.   again, imho, all this work simply isn't worth it, how often does a bearing go bad maybe twice in the life span of the car?   Just a guess...?  Compared to how long you actually own it..?

I'm not saying if you have the time and tools to do this job it's not worth doing, by all means......but, if you do not have the tools, then I say Hmmmm....?

[tolsen]

Yes as Willys already has stated, bearing cannot be drilled as far too hard. Also, if you were able to drill through bearing, you would have to dismantle bearing to clean away the cuttings. 

[Smart42]

I did not have an old Smart bearing laying around, but had an old Subaru Outback bearing (made by NTN, USA) on my bench. I decided to give it a try and see if Tolsen and Willys were right. I started with a 1/4" cobalt drill bit and, to my surprise, was able to drill through the bearing body freehand. Then I used a HSS 13/64" bit to enlarge the hole and finally a cheap Canadian Tire 1/4" 20NC tap. I was able to drill and tap the bearing with simple hand tools and little effort. If someone has an old Smart bearing around I would be very interested to hear if they drill as easily as my Subaru bearing. 

 

 

 

 

 

 

[Mjolinor]

That is not a bearing.

[Willys]

I agree, that is simply the soft body that the bearing sits in, unless you show us grease pumping out between the race and rollers of the bearing. Unless this bearing insn't the same design and has an inner and an outer race which the bearing ride on allowing a drill to slip between the bearing races.....More knowledge needs to be shown to be accepted....imho. I can't believe a bearing race can easily be drilled or it would simply wear out in a hurry from daily use...?   No offense intended just I can't believe this hole has gotten to where the grease needs to be.  I hope I'm wrong as this may mean we can all go back to grease nipples and never ending wear thanks to a simple idea of having to put grease in a grease nipple.  IMHO, mechanical devices would all last multiple times what they do now IF they all had ways to add lubricant to them like in the olden days when owners knew that self maintenance wasn't a four letter word...lol.

Just think of  all the money the manufactures will lose if this were the case.....all for the price of a tube of grease.!!!!

Edited March 12, 2023 by Willys

[Mjolinor]

Easiest way is a spark eroder. Not hard to make and will make a hole in anything.

[Smart42]

Here are a few more pictures. First one shows the bearing with the inner race in place and a bolt through my drill hole showing where the grease would flow. Second shows the same with the inner races removed. Third is a close up showing the front inner race removed, the rear inner race in place and the bolt through the hole on the bottom. The grease would flow between the inside of the bearing body and the outside of the inner races to the ball bearings and out the seals. There is space between the inside of the bearing housing and the inner races where my drill hole is. I am sure the races are hard metal, but the body in between clearly is not and this method avoids touching the races. It is enough to drill a hole and use a drive in grease fitting no tapping necessary. With careful drilling, blowing the chips out frequently and using a greased drill bit for the last bit the amount of cuttings getting in to the bearing will be minimal. This might be doable with out disassembling the bearing or even removing it from the vehicle.

 

 

Edited March 12, 2023 by Smart42

[Willys]

OK, I'm going to have to find an old bearing now and see for myself.....augh...lol.  It just doesn't make sense that we haven't been doing this from day one to save our bearings if it is possible.  imho...?   Hmmm...?

[tolsen]

What is the plan for removing swarf?

[Willys]

Just grind it in....?  I agree the whole bearing must be dismantled and washed out for the perfect results...?

[Smart42]

5 hours ago, tolsen said:

What is the plan for removing swarf?

if the bearing is disassembled like you did, simply clean it out; which of course is best practice as long as other components are not damaged during the process. Or, drill carefully and blow swarf away frequently. Last bit slow with a greased drill to catch swarf without taking it apart. What do you think will happen if a wee amount of soft metal swarf gets in to a large bearing with hard steel components? These are not high speed precision bearings designed to spin at 100K RPM. At 120 km/h they spin at 1100 RPM.

 

Tough crowd here this week: first y'all say it is impossible to drill a hole where I proposed. Only with a mill with top quality bits or spark eroder. Then I show you proof it can be done readily. You do not believe I used a bearing, and I show you I did. Now we fuss about a possible fleck of soft metal entering a hard metal bearing designed to operate in a dirty environment..

Edited March 13, 2023 by Smart42

[MikeT]

Disassembly is not a good idea, especially for ball bearings. Tapered rollers may support it better. Old grease supplemented with new is definitely better for ball bearings. I'll explain why if you want. Maybe you already know.

[Mjolinor]

You did not drill a bearing. You drilled a hub with two bearings in.

[Willys]

4 hours ago, Mjolinor said:

You did not drill a bearing. You drilled a hub with two bearings in.

This what i also think has happened....without starting WWIII....personally I have never been able to make a hole in a bearing race and I have been doing this sort of thing all my adult life....mostly on jeeps where constant flushing of contaminated grease etc is a weekly problem after playing in the mud.   I don't own a mill with specialized cutters so that avenue is out for me which imho is the only way to possibly manage this..?

Again.....not wanting to start WWIII....I just can't see it even as much as I want to.
I would love to see the actual hole in the race where it pops through body of the hub so we can see if it did manage to position itself perfectly between the two mating inner bearing races...?

Not trying to be a dick or offend, just wanting to see it be a possibility so I can do the same.

Smart42....don't take it personally as I'm sure we all wish we could be able to solve the bearing issue once and for all....!
Maybe this bearing has a space between the two inner races that allows for this to happen?  I don't know, you did say it wasn't a Smart hub right????  

Heat is on in the garage so if I have time I will investigate a rear hub to see, but I have a busy day planned.

 

What hub is that, it looks very much like an axle stub hub/bearing from a small trailer like you buy from Princess Auto...? That hub has two smaller bearings compared to two pressed together wide bearings like an automobile would have...? IF I remember correctly the smart  and also the wife's Honda hubs have much wider bearings with the inner bearing races pressed tightly together..?  I tried to replace the bearing in the wife's Honda CRV by pressing the bearing out only to separate these two inner bearing races which forced me to buy a whole new expensive hub. This is why I think the Smart uses the same type bearing..? Again not wishing to start WWIII....

 

Edited March 13, 2023 by Willys

[Mjolinor]

Mostly nowadays it aint two bearings pressed together it is one outer with two bearing inners in. Spark eroder is the only sensible way to make holes in it.

 

They also mostly have the ABS magnet built in as well now.

 

Not talking Smart here, just generally speaking.

[Willys]

What is a spark eroder..?  pic...?

 

[Mjolinor]

It is a thin tube that you pump an electrolyte down, paraffin, water , most liquids will do.

 

You use it as the anode and the work is the cathode (i probably have that the wrong way round, old man memory).

 

You feed it with an modulated DC signal and it creates sparks that eat away whatever it is sparking to. It is used mostly to create complex shapes in solid metals for example making dies for injection moulding or drop forging etc. It is just about the only way to remove a broken tap.

 

Goodle EDM

 

https://www.amedm.co.uk/spark-erosion-explained/

 

They are not hard to make but you really need a milling machine to provide the feeds for the tool.

Edited March 13, 2023 by Mjolinor

[Willys]

12 minutes ago, Mjolinor said:

It is a thin tube that you pump an electrolyte down, paraffin, water , most liquids will do.

 

You use it as the anode and the work is the cathode (i probably have that the wrong way round, old man memory).

 

You feed it with an modulated DC signal and it creates sparks that eat away whatever it is sparking to. It is used mostly to create complex shapes in solid metals for example making dies for injection moulding or drop forging etc. It is just about the only way to remove a broken tap.

 

Goodle EDM

 

https://www.amedm.co.uk/spark-erosion-explained/

 

They are not hard to make but you really need a milling machine to provide the feeds for the tool.

I have never heard of such a tool, very interesting.  Thanks.