[W126 Coupe] Rack & Pinion Steering

[Alexander Hochhausl]

This is the missing link! I can't understand the use of Pitman-arm
steering in the 20th century! I have been thinking about this mod for a
while. I love everything about the SEC but the sloppy steering! When my
steering box went ~ 1 month ago I bought a rebuilt, and it has more slop
than my original. OK, even if you loved the Pitman arm concept, why does
it not have a pre-load adjustment lit the R&P does. Not the "hard"
adjustment, but a spring-loaded pre-load. I tried to make something one
my 380 SLC in this manner, but failed miserably - not mechanically, but
could not keep the fluid from leaking. That, and the miserable, idler
arm pivot - so much slop! It is the last remaining source of high speed
(120+MPH) vibs I have. I have replaced the bushings, bolt, etc. but for
such a precision car design, it is just ugly. Would you be kind enough
to share what R&P you installed?
 
BTW - I fully respect the cost-vs-wife knowledge analysis - I have the
same issue with my Supercharger set-up. I'm still trying convincing my
wife that it's for better gas mileage! - but not sure if she believes me
or if she's playing me for a sucker!
 
Thank You,
 
Alexander Hochhausl, PE
Tel: 516-909-3794
 
-----Original Message-----
From: mbcoupes-bounces at mbcoupes.com
[mailto:mbcoupes-bounces at mbcoupes.com] On Behalf Of Mike R.
Sent: Tuesday, January 22, 2008 9:44 PM
To: Mbcoupes
Subject: [W126 Coupe] Rack & Pinion Steering
 
Well, I finally got something done on the FrankenBenz. After a
significant education on bump steer, I have the rack & pinion (R&P)
installed in the car. This is the final configuration and it actually
works. The new crossmember is 1/4" steel and is much stronger than the
MB sheet metal crossmember. The motor mounts for the LS6 will be bolted
onto this crossmember, which is the next part of the project. This is a
power rack, so a couple of hydraulic hoses will be needed later.
 
The crossmember can be made to take the MB engine mounts. This should
work just fine in an SEC with the stock motor and tranny, but it needs
to be checked for clearance under the engine. That said, it's not that
hard (now) to put the R&P in there. But.. it is expensive. For example,
that double universal joint in the steering column is $170! I probably
have $1,000 in the setup (and if you tell my wife that, I'll deny it
forever). 
 
The idler arm bracket on the left side of the photo does not need to be
there, but so far it doesn't impact any other installation so I'll leave
it alone. It's just sheet metal spot welded to the frame, so it can come
off easy. 
 
Two advantages to the R&P that I can see - it's a R&P and that should
increase steering feel, plus the MB steering box is gone and that opens
up the drivers side for much better exhaust systems. That bearing block
(shiny thing in the steering column) bolted to the frame rail is about
half the height of the steering box. I'll know much more about
clearances in a day or so when I put the replica engine back in there to
work on the motor mounts. 
 
That 4x4 on the transmission cross member is a first guess on the height
needed for the tailshaft. I'll bolt an empty transmission housing to the
replica engine and toss it in there, then see about the driveshaft
alignment. We are having fun now!!

Y'all take care,
Mike R.
(702) 494-8056
 

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