[DeTomaso] Ferrari Steering Rack Comparison

[Joseph F. Byrd, Jr.]

Thank you for the write up and photo's.  
Just "arm chair" mechanicing ... but instead of machining the rack, why not
have a new support block made to mate?

I think I understand your description, but I need to put my hands on it and
hopefully this afternoon I'll unpack my new one and look.  The rack is about
the only piece still attached to my body so I can't compare

Joe/5177/NC

PS...Sorry for the direct reply Asa Jay...eventially I'll get the hang of
how to reply 

-----Original Message-----
From: DeTomaso [mailto:detomaso-bounces at poca.com] On Behalf Of Asa Jay
Laughton
Sent: Saturday, July 25, 2015 22:37 PM
To: detomaso at poca.com
Subject: [DeTomaso] Ferrari Steering Rack Comparison

My apologies, some of you will get this twice (once as POCA and once as TPR)

Hi all,
Since I've not seen another real comparison yet, I figured I'd pop in here.
Attached are all the photos that accompany this comparison.

I recently needed a steering rack to do a comparison with the one installed
in my Pantera.  This was because a friend drove the car and said he felt the
rack was dangerous and should be fixed or replaced.  
The easiest thing to do was to make a comparison.

Peter (The German) Menyhart of The Whitehorse Ranch, fellow Pantera owner
and racer, just happened to have one of the ebay Ferrari steering racks
everyone has been talking about.  He graciously shipped it to me so I could
do my comparison.  Peter is in the midst of a restoration project and is
able to part with it for a while.

The rack is very well packaged in an oversize box.  It does not come with
tie-rod ends installed.  The boots are a big larger than stock DeTomaso, and
they are clamped on with those funny one-time use on the large end and a
friction/spring on the small end.

The movement of the rack feels rather stiff, not as hard as the one out of
my car but still not quite "like butter."  However, you'll note from the
photos the tension can be adjusted without the use of shims.  I will work
with that later.  So far, one plus for this rack.

I took measurements of the tube diameter in the mounting bracket areas.  
The two tubes are within .005" at each location.  The overall length is the
same as my Pantera rack.  The big difference, as has been mentioned, is in
the drivers side bracket area which contains raised ribs for either side of
the bracket.

Now, here is where I discovered something interesting.  I was having a very
difficult time getting a good reading with my inside calipers of that area.
The bracket was easy to measure at 0.624" outside dimension but the space on
both racks measured at about .555" in width and that didn't make sense.

Well, I had to put my grandpa glassed on, but found the reason.  Nearly the
entire ridge on the Pantera rack has a shoulder on it, that goes from about
.055" at the bottom against the tube, to just under 0.624" at the outermost
edge.  Looking at the photos of the bracket you'll note it too has a bevel
cut into the semi-circle.  In my case the brackets still don't fit quite
flush to the Pantera rack.

The brackets -don't- fit the Ferrari rack at all.  You'll note from the
close-up of that rack, there really isn't any bevel to it at all; it's
nearly 0.555" from tube to outer edge.  In order to get this to the 0.624"
it needs to be to accept the brackets, I'll need to machine about .070"
split more or less equally on both sides of the channel.

The last thing to note is that the tie-rods are a bit beefier.  However,
they -are- cut with the same diameter and thread as the Pantera rack.  
In the photo of the tie-rod ends, you see the Pantera rack with the lock nut
on the tie-rod end, and a used/spare/old Pantera tie rod threaded onto the
Ferrari rack.

So there you have it.  The rack is nearly identical with the exception of
beefier tie-rods (good thing), adjustable tension adjust (good thing), and
narrow mounting bracket channel (bad thing but workable).

Mark Skwarek recently did one of these for his Pantera as well and used an
end mill with the rack mounted in a vise, cutting a path, turning the rack
and cutting again until he got all the way around.  That's probably what
I'll do as well.

The best thing would be to completely disassemble the rack and chuck it up
on a lathe, but I really don't want to take it apart; after all, it's not
really my rack.  :)

There, any questions?
Asa  Jay

--
Asa Jay Laughton - W7TSC, MSgt, USAFR, Retired &  Shelley Marie Spokane, WA
******************************
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