Steering Rack Tie Rod Clevis or Joint

[Shep]

Happy New Year Folks,

I'll be needing to order a new steering rack for my CF before next season, the current one's shot. (No, it can't easily be rebuilt, or re-bushed - been there, investigated that.) The Pegasus custom piece seems reasonable enough (unless someone can suggest an alternative).

Anyway, since I'm essentially starting from scratch and wil be ordering a custom configuration for my car, I wanted to change the joint between the rack and the tie rod.

My current rack has EXTERNAL threads at the ends - something like 7/8-14, and then there's a big honkin' internally threaded clevis screwed on to receive the rod end from the tie rod.

My question: if I go to an internally threaded rack (1/2-20?) and an externally threaded clevis, where do I buy the clevis (and obtain the dimensions, so I can work the dimensions of the custom steering rack)?

Alternatively, what is the approach used on modern (late '90's and newer) formula cars? Is it a "Renault style end joint" as mentioned in the Pegasus catalog? Or something different? Either way, where would someone buy one?

Thanks,
Erik

[Rick Kirchner]

The more modern cars have the end of the rack slotted, and a tiny heim goes in the slot. The rack is backed up with a aluminum collar around the end and a pinch bolt holds it all together. This will work if the required rod end size is not too big, and, if the angle of the steering link to the rack doesn't exceed the angular capabilities of the rod end.

[Shep]

Thanks Rick,

Well, I'm assuming with the Club Ford I'll be at least a little more softly sprung than the modern cars and will need more angular compliance, so I guess I can't go with the "slot" option.

Turns out the 7/8-14 external thread is for the Renault ends I mentioned earlier (didn't realize the Renault end was the *old* style used before clevis/rod ends [dogrings.com]. Found the exploded view of a Lola 540 rack - thanks to Allan T Chou I believe).

Anyway, two questions for the group:

1. Why would I want to, or not want to, use a Renault syle end? Why did the industry get away from them?

2. Where could I purchase a new male-threaded clevis for the ends of the steering rack if I choose to go in that direction??

Thanks,
Erik

[Roux]

My Royale RP16 had a slotted arrangement as described above for the modern cars, and that beast came from 72/73. It also had a ton of chassis movement. The material around the through bolt was pretty thin. I should warn the new owner to rethink all of that.


My newer RP31's both have a threaded female hole in the end of the rack and a clevis designed so that a cap srew fits inside the clevis and holds it hard up against the end of the rack. So the clevis has a hole in it it right where you would presumably prefer to have a piece of thread protruding outward. Can get you a photo if I have not described it well enough here. This same clevis shows up again on the RP31 at the rear upright to trailing arm attachment. Seems to work and I think the bolt is 3/8