Paul,
If you tighten the nut on the end of the axle to 70 Ft. Lbs. I can tell you
for certain there will be no endfloat. (unless you have superman doing the
checking)
so where does the end float referred to in the manual come from and why
doesn't the wheel lock up when torqued this tight?
If you have a wheel bearing laying around pick it up and look at it. If you
hold the inner race stationary you will notice a small amount play in the
axial direction in the outer part of the bearing (caused by clearances in the
cage). Now go wipe all that grease off you hands.
When an MG front hub is assembled it goes something like this. The inner
bearing is against the shoulder on the axle stub then comes the spacer, then
shim(s) then the outer bearing, washer then the nut. When torqued down the
nut presses against the washer which presses against the outer bearing which
presses I sure you get the idea. As I said at the beginning of this post when
torqued to 70 Ft. Lbs. there will be NO endfloat in THIS part of the assembly.
The endfloat comes from the play inside each bearing. By adjusting the amount
(thickness) of shims in the pack you can adjust the amount of endfloat and the
amount of preload on the bearings. Look at the procedure in the manual, it
tells you to put too many shims in to create excessive endfloat, measure the
endfloat and adjust the pack accordingly. If you were to take out too many
shims the endfloat would be non extant and the preload excessive causing
premature bearing failure. If the endplay is excessive the preload will be
low causing vibration in the brakes, and once premature bearing failure. In
this case adjusting endfloat provides a way to preload the bearings correctly,
kinda neat actually. As once set up correctly as long as no parts are
replaced (or lost) any idiot can repack the wheel bearings and get it right.
I hope that this clears up any confusion.
Rick Ewald
In a message dated 3/30/99 10:58:18 AM Pacific Standard Time,
paul.hunt1@virgin.net writes:
> The Leyland Workshop Manaul and Haynes are quite clear in respect of the
> MGB, there should be an end-float of .002 to .004, not a preload.
>
> PaulH.
> http://freespace.virgin.net/paul.hunt1/
>
> -----Original Message-----
> From: REwald9535@aol.com <REwald9535@aol.com>
> To: paul.hunt1@virgin.net <paul.hunt1@virgin.net>; mgs@autox.team.net
> <mgs@autox.team.net>
> Date: 30 March 1999 07:24
> Subject: Re: pulling out the spacers in the front hubs
>
>
> >Paul,
> >Conical bearings need some (not much) pre loading. There are several ways
> to
> >do this. MG used a spacer and as you mentioned a torque of 40-70 Ft Lbs.
> >With the spacer and correct shims fitted this gives the correct pre load
on
> >the wheel bearings. Other makes have a different way of skinning the same
> >cat. My company (Volvo) on 240's have the technician torque the wheel
> >bearings to 30 Ft. Lbs. and spin the wheel to center the bearings, then
> loosen
> >the nut 1/2 turn and retorque to 11-15 inch Lbs. this also pre loads the
> >bearings to the correct amount. Either way the idea is to remove the slop
> and
> >not to over load the bearings which would cause a premature failure.
> >Rick Ewald
> >67 MGB
> >
> >In a message dated 3/29/99 12:30:42 PM Pacific Standard Time,
> >paul.hunt1@virgin.net writes:
> >
> >> As well as the spacer and shims, when tightened to the correct torque of
> >> 40 - 70lb ft, strengthening the axle shaft they also stop any tendency
> for
> >> the inner races to spin on the axle. The correct shims will give an
> >> end-float of .002 to .004in, not a loading of 11 to 15 in lb.
> >>
> >> PaulH.
> >> http://freespace.virgin.net/paul.hunt1/
> >>
> >> -----Original Message-----
> >> From: Karl Shultz <karl.shultz@ibm.net>
> >> To: MG List <mgs@autox.team.net>
> >> Date: 26 March 1999 05:20
> >> Subject: pulling out the spacers in the front hubs
> >>
> >>
> >> >Hello MGers,
> >> >
> >> >Hope all is well with you getting your assorted brit cars ready for
the
> >> >warm season. I'm coming along myself - I've replaced the brake lines
> >> >(which looked as old, if not older, than the entire 73 B itself), the
> >> >heater control valve (with a gasket now) some hoses, and made some
> hacks
> >> >into the electrical system whose effectiveness seems to vary day to
> day.
> >> >
> >> >Anyhow, I took a trip to Flying Circuis Cars in Durham, NC. They're a
> >> >Brit car specialist where I buy my parts. So I go to buy shims for
the
> >> >front hubs (which rattled about horribly) and a guy came in from the
> >> >garage area telling me something interesting. I'd like to bounce this
> >> >off the group, it seems odd.
> >> >
> >> >He said that the big spacer, and the accompanying shims, could be
> >> >installed in the trash can rather than the hub. "Conical bearings can
> >> >accept the load themselves no problem; people used to think you had to
> >> >make perfect contact between the bearing housings with those shims,
but
> >> >all the cars we work on, we just pull all that stuff out.
> >> >
> >> >Odd, no? I tried it. The hub can be put together and adjusted up
just
> >> >fine without all this stuff. But concerned for the longevity of the
> >> >bearings (they say "made in england," so they must be as old as the
car
> >> >too...) I haven't really finalized the work.
> >> >
> >> >Any thoughts on this odd suggestion?
> >> >
> >> >--
> >> >Karl Shultz
> >> >95 Integra GS-R, black, loud
> >> >73 MGB, orange, only marginally drivable
|