Greetings;
I have been fighting steering issues on heavily modified Brock/Daytona/Cobra coupe , - We found a way to improve the steering reaction and durability ( we think ) , specifically , in the U joints of the steering rack and shaft(s).
As with any manufacturer; Mercedes, BMW, Porsche, - there are steps that need to be taken when you move a car from a stock configuration, to an upgraded wheel and tire package . - larger wheels a wheels and tires introduce new forces into a new physical energy / dimensional realm. -
- it is very easy to bend suspension parts when you have more contact patch than stock - it is just a bigger lever.
this can foster some tweaking in the steering / u-joints and they should be checked as a maintenance item to preclude any free-play.
Note: if you are experiencing 1/8" to 1/4" free play at the wheel, this can be as little as 1 to 2 mm side to side in a Steering U Joint. (from center native position, transitioning from L to R on center ) - even joints that are "good" from the factory, can be bent and tweaked by forces that they were never designed to carry/push.
This is why people buy M Series, AMG, or other motorsport "improved units" .
In a modified car, - Whilst the original joints might be OK for the first X miles, -I think they have the opportunity to widen and lose their shape ; however the joint was probably never designed to have the duty cycle of 4' of tire contact patch pulling on it in a 90 mph sweeper, whilst it is being beaten down by header heat/cycles. (all of this while beating down the bozo in the GT2-911 to make him feel like a poser, showing him your Shelby or Brock wheels as you fly by.
In looking into this area for a possible HD improvement part, we found that borgeson USA makes a 1 for 1 HD replacement for the top Steering U Joint, - and what we thought was a 1 to 1 for the bottom. -
However the bottom joint ( Rack to steering intermediate shaft ) was about 1" shorter than required with suboptimal spline engagement. This is not the fault of the borgeson joint, it is just a weird setup with the Coupe - the geometry is just complicated at the bottom - you cannot change the inclination angle of the intermediate shaft without touching something. ( it is just really tight under there )
So we took the lower Borgeson, - and then we sliced off the nose end (rack side) of the native SPF joint, and cut a taper into it for easy welding to the nose of the HD borgeson unit -
The Wins;
1. Overall joint is slightly longer for better spline engagement. ( physically cannot come out without unbolting rack)
2. HD American Bearings and case metal ( USA!!)
3. Welded on our crank grinder for super straightness. (Take a Peek -)
See the next 3 videos for the welding and QA process.
panavia3393's Channel - YouTube
panavia3393's Channel - YouTube
panavia3393's Channel - YouTube
Our goal by offering these ideas and improvements is to uplift the experiences of the enthusiast owner!
Let me know if you need help - Steve