andy here, using mcmarks computer ...

quick question:
putting back together my 911 front end and got the nut for the hub as tight as it goes, wheel still spins freely.
shouldn't there be some drag ???

how tight is tight enough ???
Andy

Bearing races fully seated? Correct bearings? Got the washer in there under the nut? There should be plenty of adjustment beyond tight, although the wheel "might" still move even when the bearings are too tight. The Cap'n

Tight enuff is when you can move the big washer in there with a screwdriver....not wedge it around, but not sloppy, either.
It's a "touch" thang.

Andy...you know better.....rollerbearings were invented so there would be minimal drag. If you feel drag, the bearing is bad.

RTFM

QUOTE (Cap'n Krusty @ Jan 21 2006, 03:36 PM)

Bearing races fully seated? Correct bearings? Got the washer in there under the nut? There should be plenty of adjustment beyond tight, although the wheel "might" still move even when the bearings are too tight. The Cap'n

bearings and races where in the hub when i took if off this morning. i did not replace the bearings, just the rotors ...

yes, washer is there ...

with the nut full tight, the wheel still spins freely, but it does not wiggle ...
Andy

Since you've convinced yourselves there should be drag....tighten the mfer until you feel drag and see how long the bearing lasts. It's a taper bearing and the tighter you make it, the more you force the rollers into the race....lubrication won't last long..

You might want to Google frictional coeficients for roller bearings.

QUOTE (SLITS @ Jan 21 2006, 03:57 PM)

Since you've convinced yourselves there should be drag....tighten the mfer until you feel drag and see how long the bearing lasts.  It's a taper bearing and the tighter you make it, the more you force the rollers into the race....lubrication won't last long.. You might want to Google frictional coeficients for roller bearings.

you're missing the point ...

when i tighten the nut as far as it goes, there *should* be some drag on the wheel ...
i remember brad showing me a overtight bearing and the wheel hardly moved ...

i know the bearing should not be too tight for operation, but i went from loose and wiggly to way to tight with NO effect on the wheel rotation ...

that can't be right ...
Andy

Ah allus went wif the method of tightenin until thar ain't no slop when ya wiggle the top and bottom uv the rotor/wheel. But then agin, Ah'm ignernt.

manual says tighten to 10 lb/ft, rotate wheel back off till you can just move the washer..

Real world says rotate wheel while tightening the nut till you feel it( feel resistance from tightening the bearing), back it off, and drive the car for a bit, then recheck bearings.. check bearing not by turning the wheel but but rocking the wheel in Z axis.. ie hands at 0 and 180 try and wobble the wheel.. you should barely feel movement

Sorry Andy....of all the wheel bearings I have tightened, I have not felt the drag like you are talking about. I run them up tight and back the nut off 1/4 turn, check for looseness (movement of hub in relation to spindle). If I *feel* it moves to much I tighten it about 1/16 - 1/8 of a turn and do it again.

I also have not exerted sufficient force on the spindle nut to "lock" the bearing to the point where it won't turn.

My technique has been to snug up the wheel nut very tight, while also using a big screwdriver against two temp. lug bolts to spin the hub as I tighten. This keeps the rollers from dimpling the races. Usually, the wheel will barely turn once fully tight like this. I then back if off completely, then tighten it down WITH MY FINGERS until I can't feel any wiggle in the wheel.

Alfa manuals (very similar front end design) have you tighten to 35 ft/lbs, then back off, then retighten to 7ft/lbs.

If you can't feel any wiggle in the wheel, it's tight enough. If you can't spin the wheel freely as well, it's too tight.

QUOTE

Real world says rotate wheel while tightening the nut till you feel it( feel resistance from tightening the bearing), back it off, and drive the car for a bit, then recheck bearings.. check bearing not by turning the wheel but but rocking the wheel in Z axis.. ie hands at 0 and 180 try and wobble the wheel.. you should barely feel movement

Once upon a time I managed to tighten my bearings to the point that it was very tight and I felt a touch of drag and there was no wiggle. Thought it was the way to go. Eventually the outer bearings on the driver's side destroyed themselves and the inside of the bearing galled to the spindle. This occurred at an AX on a beautiful spring Saturday about 3 years ago. I had to cut the bearing, then split it to get it off the spindle. Enough material fron the bearing was still galled to the spindle that I spent hours with strips of emery cloth, carefully buffing the bad material off and being extra careful not to eff up the spindle itself. All to the tune of Porsches racing around in circles and loads of people coughing up unwarranted, unhelpful and unusual advice. I got the car back on its tires just as the last car did its timed runs.

I have used the above method ever since and never had a problem. Truly, you want to feel the tiniest bit of "click" when rocking the car on the "z axis."

QUOTE (hmeeder @ Jan 21 2006, 08:22 PM)

Truly, you want to feel the tiniest bit of "click" when rocking the car on the "z axis."

I agree. The movement should be noticeable but just barely so. The rear wheel bearings usually have more play than the fronts should have.
I have also used the method JP mentioned but it is a bit tougher to get the right feel that way IMO.

I'm with Slits,

Been doing it that way for over 40 years.. Not 1 problem.

Twystd1

QUOTE (Twystd1 @ Jan 22 2006, 01:24 AM)

I'm with Slits, Been doing it that way for over 40 years.. Not 1 problem. Twystd1

As was I till I started working on Porsches.......they had this "other way" of doing things. Dunno why, so I do it their way, but do the seating & "checks" as I've always done

Holy shit I sound old...

40 years...yada...yada..yada.....

Hell....Emotionally i'm bout 16..... I think...crap...oldtimers just hit again.....

What was I saying....????????????

Twystd1

QUOTE (Twystd1 @ Jan 22 2006, 04:31 AM)

What was I saying....???????????? Twystd1

I haven't a clue

I rotate the hub or rotor whilst tightening the pinch nut, until it's tight enough that you can't move the thrust washer, and then back it off enough that you can just move the thrust washer whilst prizing it with a screwdriver.

I had to throw in "whilst" a couple times. They use it in the Haynes manual, which is where I learned the above technique about 26 years ago, and I've never roasted a bearing.

If the bearings are new then you can tighten em down so they don't move but if they are used then I found you can't ususally.

Use JP's Porsche method and you'll be fine.

I too have been using this method since shoot 1969 so its works.