SPR-ZM into a FOX via MMST-13, U-joint question.

[SkurdalenFox]

I’m wrapping up the installation of a ‘04 Cobra rack and peanut into my 92 coupe and have a question about the orientation of the universal joints. The stock fox steering shaft had the upper u-joint situated such that the shafts of the u-joints were pointing at 12/6 and 3/9 o’clock with the wheel in the straight ahead position. With my new rack centered the u-joints in the MMST-13 are slightly off. They are at ~1/7 and 4/10 o’clock.

So, I have two questions.

1. I am concerned that my rack may not be centered properly.

2. Obviously, I don’t want faster steering in one direction than the other. Nor do I want jerky/inconsistent rotation. Will this occur or is the angle not steep enough for it to cause a substantive rotational speed variation?

I can’t do anything about the angle of the two shafts, but I could open up the rack and clock it to put the u-joints back at 12/6 and 3/9. I guess what I’m really asking if all the trouble of doing that is worth the gains to be had. If that is, I just don't have the rack centered properly.

This picture shows the angle of the shafts to one another, but does not show the orientation of the u-joints with the rack and wheel centered and the wheel straight ahead.

[SkurdalenFox]

Originally Posted by SkurdalenFox

1. I am concerned that my rack may not be centered properly.

I know it's kind of silly to answer my own question, but I'm not. I thought I'd save someone the trouble of answering me, and perhaps there are others who'd like to know.

A tech guy at MM got back to me and this is what he said,

"Because of the splined upper section of the shaft is it typical for the u-joints to be clocked differently than with your stock setup, " Chris Phelps - Sales and Technical Assistance.

As to the question of if I will notice inconsistent steering the the current clocking of the u-joints, and whether or not those inconsistencies warrant removing and clocking the rack to achieve 12/6 and 3/9 u-joints; I’m still wondering.

[QWKSNKE]

I have a silly question.

What is the benefit of doing this install?

[Sendero]

Originally Posted by SkurdalenFox

As to the question of if I will notice inconsistent steering the the current clocking of the u-joints, and whether or not those inconsistencies warrant removing and clocking the rack to achieve 12/6 and 3/9 u-joints; I’m still wondering.

Reclock your Rack. (link)

Originally Posted by QWKSNKE

I have a silly question.

What is the benefit of doing this install?

"Softer power assist" boost curve. The 00R rack is the best one available, but there are only a few thousand in the wild. However, the 03-04 Cobra racks have the same Torsion Bar (T-Bar) but a little different valving for better low speed assist. At any speed the Fox racks are a little touchy and the ratio's a little too quick. Also, because of the valving in the Fox racks you get a non-Linear turn rate which can mask what's going on with the tires. With the R and Cobra racks you get "harder" to turn wheel, but the valving is linear giving better feedback from the tires and the ratio is better suited for big tires. Using these racks reduce the need for aluminum bushings and "hard" mounted racks.

In laymans it's better for road racing because it doesn't feel like you're turning the steering wheel on Rad Mobile (link).

[coupe]

How 'bout an SVO rack then? It's valving is superior to the regular Fox.

[SkurdalenFox]

Originally Posted by Sendero

Reclock your Rack. (link)

From the link, "The Mustang steering gear has an 8-tooth pinion, so it can be indexed in 45 degree increments." Being that the u-joints are only about 10 degrees off, I'm outta luck.

Nevertheless, I can't feel that it's any different side to side. I suppose that since the angle is pretty slight, there really isn't too much of a difference. Whatever difference there is, it is probably being masked by the power steering system.