Let me explain a bit.
The in/lb rating you see/refer to is the amount of rotational torque needed
on the pinion bearings, measured without the axles or the ring gear
installed.
This is the pinion bearing preload.
In order to accomplish this, you need to add/subtract shims from the races
on the pinion shaft and tighten the pinion nut to 150-175 (or whatever
youspec call for) FT/LB.
Once the pinion nut is tightened to say 175FT/LBs, then you take a in/lb
torque wrench and rotate the pinion shaft (via the pinion nut) and measure
the required torque it take to maintain it spinning, not the amount of
torque required to start iot spinning (which will be higher) but what it
takes to keep it spinning.
Again, if the amount is too low or too high, you need to add/remove shims
to get the correct torque.
You can see whay you can't set the in/lb preload while spining the axles
and ringgear...because the rotational forces applied by each will most
likely be more than the pinion bearing pre-load setting required.
Now I've never set up an original TF rear, but have done a few Dana's and
Spicers from later model cars and trucks, the original TF rear is a bit
different as I recall, I'll look in one of my manuals to see if there's any
quirks.
> [Original Message]
> From: A.B. <bigfred@unm.edu>
> To: Wayne Osborne <wayne@chevytrucks.org>
> Cc: <oletrucks@autox.team.net>
> Date: 1/22/02 10:26:58 AM
> Subject: Re: [oletrucks] pinion flage nut question.
>
> Hi, thanks for the help,
> maybe we're not on the same page because I can't find any "crush sleeve".
> When I took off the nut, the only thing behind the flange (the thing the
> drive shaft connects to at the u-joint) was a tapered roller bearing.
> the nut that holds the flange on had a washer as you describe behind it.
> All I did was change out the seal. Also, I see no mention of a crush
> sleeve in the book. Should I just tighten the nut to 20 in-lbs and check
> as described below? thanks again...
> -alfie
>
>
> On Tue, 22 Jan 2002, Wayne Osborne wrote:
>
> > If wrong i'm sure someone will correct me..... Thats sounds about the
> > correct amount of torque..This setting is directly related to the
tightness
> > of the rear end gear mesh-to tight as mentioned below and it'll overheat
> > and fail. Here's a bit more info the subject: Search the archives for
many
> > other emails on the subject.. Rear end setups can be tricky as to why
> > most folks let the pros do it. A bad setup and you can ruin a 400 dollar
> > ring/pinion gears--wayne
> >
> > be sure new crush sleeve is used. be sure big flat washer that goes
> > behind the retaining nut is used.......(i have seen them left
out).....use a
> > new retaining nut.........use lock tight red on the threads when you
> > install the nut......it takes about 200 ft-lbs of torque to crush the
> > sleeve......
> > so i use my 3/4 drive socket and 4ft handle to do the pulling.....i
have a
> > open end wrench that fits the outside of the yoke to hold it......i let
it
> > turn up against the floorboards or frame to lock it in
> > place..........carefully
> > turn down the nut crushing the sleeve until there is no fore and aft
move
> > ,ment in the pinion shaft......turn just a little bit tighter......so
it takes
> > about12-15 inch-pounds of torque to twist the pinion shaft in direction
> > of operation............test drive it......under35 mph........ for 35
> > mins....and check the housing near the yoke for heat buildup.....you
should
> > be able to hold your hand on the housing with no pain...............if
you
> > assemble it too tight it will run hot and fail From:jerry mungon
> >
> >
> > At 09:59 AM 1/22/02 -0700, you wrote:
> > >Hi,
> > >I'm trying to figure out how tight to make the pinion flange nut on my
'58
> > >rear axle. The manual asks you to record the torque it takes to spin
the
> > >axle. When you put the pinion flange nut back on, the manual says to
> > >incrimentally torque the nut while checking the preload against the
> > >previously recorded torque. this is a very small number (<20 in-lbs!),
so
> > >I'm finding it hard to believe that I need to only torque this nut to
such
> > >a small setting. The Book makes no mention of a preload torque. Has
> > >anyone encountered this situation? Thank you.
> > >-alfie
> > >oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
> >
> > Wayne Osborne
> > 1956 Chevy Pickup
> > LaGrange Ga.
> > http://www.chevytrucks.org
> > http://www.chevytrucks.org/wayne
> > oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
> oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
--- Mike
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