DeTomaso Mailing List: October 2000, Message #207

Chance wrote:

>I'm getting ready to install Hall's single adjustable spreader bar.  I =
was wondering if any of you guys could give me a little advice on how to =
proceed.  I'm assuming that I want to jack the car up in order to remove =
the load from the back wheels before I remove the stock bar. 

>>>Right.

> After =
putting in the bar, how tight do I want to make it?  Any other =
precautions or things I should look for?

>>>Well, what you DON'T want to do is use the bar to physically spread the 
panels.  I've seen guys lay the bar in place, then get their biggest, 
manliest wrenches out and just crank the hell out of the thing.  That puts 
quite a strain on the mounts, strain on the chassis and I suspect if you got 
too rambunctious, could lead to stress cracks in the paint.

I'd jack the rear wheels, set the bar in place, slide the two mounting bolts 
in place and start to thread the nuts on.  Use your Manly Wrench to spread 
the bar until the mounting bolts are firmly bottomed out--you want it snug, 
but not ridiculously so.  Once that's done, tighten down the locknuts on the 
spreader, then tighten down the nuts on the mounting bolts, and you should be 
in business.

IMHO, the pretty aluminum spreader bar with the engraved DeTomaso and Pantera 
scripts is beautiful, but the plain-jane square tube version is MUCH more 
functional.  Why?

Well, the aluminum bar's sole interface with the chassis is via the 
relatively puny mounting bolts, which mount the bar to two fairly flimsy 
sheet-metal tabs welded to the surface of the inner wheel house.

The plain-jane square-tube bar, developed considerably later, uses a much 
more logical approach--the ends of the bar are designed to be jammed into the 
pocket that exists underneath and outboard of each mount.  The bar acts upon 
a large surface area of very solid metal (well, solid by Italian standards 
anyway) and the mounting bolts have very little work to do--they basically 
just keep the bar from falling out of the car!  But the flimsy tabs no longer 
bear the onerous task of transmitting mega ft/lbs of force to the chassis; 
they simply locate the bar and keep it in place, and the ft/lbs go straight 
from the steel bar to the three-sided steel pocket.

So installation of that bar would be essentially the same, except that you 
tighten the spreader nuts with your Manly Wrench until the bar is secure in 
the pockets on each side, then tighten the mounting bolts/nuts to keep it 
that way.  In most cases, the bolts will be some considerably distance away 
from the end of the slot in the mounting tabs, meaning the tabs aren't 
carrying any real load.

Much mo' bettah!  And that's why this steel tube forms the foundation for the 
Hall/Byars chassis stiffening kit, and the pretty aluminum bar doesn't.

Mike