On Thu, 18 Jun 1998, Don Sforza wrote:
> I'm going through the dreaded TR6 hub rebuilding thing and have just
> been informed that one "may" have been bent in the process... this guy
> is no schlockmeister, either... we'll work it out.
In defense of anyone that has tried this job - it takes a boatload of
force to pop the hub flange from the stub axle. This is documented time
and time again in the Triumphs list... according to the book of Hubs,
chapter 5 verses 21-23:
It is written:
It is most possible to bend the hub w/o the Tool.
> My question, Sir Robert has to do with the Churchill Tool that you were
> fortunate enough to borrow for your job. What is the possibility that
> this tool can be duplicated? We live in a hotbed of ingenuity and
> talent... why not?
It could be duplicated, but if the piece is machined from a billet, you
would have to start with a pretty hefty chunk of steel! The original is
cast iron. With the cast iron piece, you can also bend the hub flange,
but in so doing you can also ruin the Tool.
So, basically the tool is like a stove-pipe hat. The "rim" is drilled out
to the bolt pattern of the road wheels (4 holes, 4.5 inches on center.
The holes need to be big enough to clear the shoulder of the studs, as
they "stand clear" of the hub when they are fully installed. I think this
dimension is something like .500 + a bit more. Use tapered lug nuts to
attach the Tool to the studs. If you have wire wheels, drive the short
studs out and replace with the standard "disk wheel" studs. The
wire-wheel studs are just plain too short for use with the Tool. Note:
the "rim" of the Tool is thick - maybe as thick as .5 inches (12 or 13 mm
to you Porsche guys)...
The "top" of the hat is threaded for a BIG threaded rod - with fine
threads. I think it's something like .750 inches thick. The end that
contacts the hub is rounded so that it seats well on the end of the stub
axle. Lube this when you use the tool. The other end of the threaded rod
is machined into a hex nut, and it is rather big - like 1 inch. So, to
duplicate the actual tool, the threaded section starts out as a 1 inch
hex rod (it might even be bigger, I'm going from memory here), it is
turned down to the proper dimension, then threaded and then (I imagine)
it is case hardened or something so that it can take some serious
loading. Now the thickness of the top part of the had is crucial, because
when you crank down on the Big Bolt, it takes some serious loading... I
would not be surprised if they use some kind of threaded insert (like a
big heli-coil) to guarantee the integrity of the threads... but I don't
know for sure.
Oh, when you do this job, take the big nut off the end of the stub axle
and turn it around and thread it in so that the "ball" on the threaded
rod seats square with the axle. If you leave out this step, you will
mushroom the stub axle end, and you will develop cracks there. You will
also have a heck of a time getting the nut off once the hub flange "pops"
from the stub axle. Don't ask me how I know this. Anyone need a slightly
used TR6 stub axle?? Makes an interesting conversation piece on your
coffe table!
The height of the top-hat is obviously sufficient to accomodate the full
length of the stub axle where it stands proud of the hub, and the inner
diameter of the hat is big enough to clear the portion of the hub flange
that stands proud. I don't recall this dimension, but the min. I.D. is
the same as the brake drum center hole, as that piece also has to clear
this protrusion.
I hope this makes sense.
The only other anomolies of the original tool are that the main body of
the tool has a little "ear" in the casting with a hole drilled out that
is large enough to accomodate a 3/4 inch solid steel bar. The threaded
rod is also drilled out at the big hex nut end for another bar, I forget
if that hole is 3/4 inch or smaller. Niether of these holes are
necessary, per se, but the one in the body of the tool is used for
leverage, so if you are putting the "tool" in a vise (not just necessary,
it is REQUIRED), it would be good if the tool that you make has "flats"
that you could grab in a vise. The hole for a bar in the threaded section
is not required, but you _will_ need to but a really big wrench on it (we
used a 36 inch pipe wrench with a 5 foot pipe for leverage).
One comment about the vise thing - I have not done this, but using the
"ear" on the tool and a long pipe, it is probably better (from a leverage
standpoint) to do this operation on the car, as you would have gravity
and the 2300 pounds of mass in the car working with you when you crank on
the bolt. However a potential drawback of this method is that if you
slip, you'll probably wind up putting an impression of your face on the
rear fender if the car - and if the tool failed, you'd probably damage
the car somehow (think about those little 5/16 studs that hold the hub
assembly on the trailing arm - imagine what a couple of thousand pounds
of force in the wrong direction would do to those)... nevermind!
To give you an idea of the force required, it took both a friend and I,
combined weight probably 325 pounds or so (of course I only contribute a
fraction of that mass ;-) ), pulling on the end of the pipe to get the
think to pop - considering the leverage with a 5 foot pipe, you can see
that we were putting over 1500 foot pounds of torque on that puppy.
But the key for this whole job is that you have to keep checking the hub
flange to make sure that it is _flat_. If you start seeing daylight
between the hub flange and the tool, loosen the Big Nut and recheck the
lug nuts to make sure that they are evenly torqued and then resume.
Done in this manner, the hub flange should remain undistorted.
If you flanges are already bent, it might be possible to bang 'em into
shape, but you would most def. have to run 'em in a lathe to "true" them
after that, and I'd be leery of the surface hardening after that sort of
operation. I would most def. _not_ use a hub flange treated like that for
road racing!!!
> "And to think, it all started with a tractor!"
>
> Don Sforza dsforza@megahits.com KA1WV
> 1963 TR4 Connecticut Triumph Register CT16707L
FWIW, I think there is a person in CT somewhere that used to fix a lot of
British cars that has one of the Churchill tools. He apparently does not
do this work any more, and I think it might be possible to obtain the
tool. Another NET person found this guy a few months ago, and I have not
followed up to try to obtain the tool. If this is of interest to you, I
can try to dig through my notes and track this guy down...
Either way - good luck. If I wasn't so freakin' cheap, I'd send my hubs
elsewhere to get rebuilt. Actually, it isn't just cheapness - I need to
see all the components and I need to crack test them. After all, I intend
to drive my next car pretty hard! On the other hand, I'd really like to
find a suitable replacement stub axle and flange that uses modern sealed
double row bearings (like today's front drive cars). The new cars are
simple and they stand up to a lot of abuse... oh well. Time to dream some
more.
rml
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