I'm installing new front wheel bearings and I need a "pull scale" to measure the frictional force (9-9 in the S4 FSM). Is that the same thing as a spring scale? Such as the one seen here: http://www.americanweigh.com/product...roducts_id=709

Also, it says Does anyone know the frictional force? I'm wondering so I can get a scale that measures the proper interval.

And finally, anyone know where to buy one local? (e.g. chain stores)

 

lol, I used a fishing scale.

 

i don't even go that far...generally i go by feel. tighten until there is a certain amount of drag on the rotor as i spin it with my hand.

has worked fine all these years :]

 

You gotta use a Newton scale, same ones you would have used way back in high school.

 

Easy way. As you tighten the nut, move the washer with a screwdriver, when the washer doesn't move easily, it's too tight, then back off until the movement begins again.

 

I'll look into those. So basically a spring scale and pull scale are the same thing it appears.

I didn't use any scales in high school.

Although I appreciate the answer, that's WAYYY too vague for me.

 

I can't remember what the hell its called exactly but in physics we used those things, they're just pull scales that measure in newtons.

 

Nothing vague about the answer. If the washer binds, then the nut is too tight. That's how it's done at the dealerships/garages. Do you actually believe that the mechanics take time and us a pull scale on each car to do the front wheel bearing adjustments?

 

Why would the guy at the dealership care if it's done right? If it screws up it will likely get taken somewhere else to get fixed or it will be out of warranty at that point (assuming it's in warranty to begin with) so they make money.

I'd still rather do it the right way.

 

One of my automotive instructors ( Who grew up at, and still works with, his family's local shop that has an excellent reputation) taught me to do it this way:

1) Tighten the nut until there is no play left in the bearing assembly; not tight, just so that there is no play.

2) back the nut off from that position one "flat"

3) put the wrench to 90ish degrees (not moving the nut from the backed-off position) and let go. The weight of the wrench will put the light preload on.

If you think about it, this really works because the weight of the wrench is the only force being applied to torque the nut. His family's shop has been doing this forever, and knowing this guy, I doubt he would teach us this if he knew it was wrong or half-assed.

 

What is a "flat"?

 

I assume he means one side of the retaining nut. You're over-worried about this, just get it to take the slack out with a very light pre-load, just until you feel slight resistance. I've done it this way on hundreds of bearings as a mechanic, and I do "give a ****"