short telescoping steering shaft

[Alponcho]

I'm having new headers built for my Pontiac powered 70 Formula with DSE subframe, and while this is being done, I'd like to replace the solid DD steering shaft between the column and steering rack with a telescoping shaft for the sake of safety. The problem is that the shaft is only 12" long, and I'm not sure the shortest Borgeson telescoping shaft (450024) can be cut that short. It's advertised as a 24" shaft, and the product info says it can be shortened by 10", but the instructions provide a generic example in which the shaft is shortened to 12". Moreover, even if it can be cut to 12" then not sure how much further it will telescope in. Looking for some input on whether this shaft will work or whether there are other options out there. Thanks in advance.

[dontlifttoshift]

Front steer A and F bodies with steering boxes, all get collapsible shafts here. Because the rack and column are not in line in your application, the telescoping shaft is not required.

To your question, The amount of collapse is limited by how much overlap you have. As it ships, the 24" shaft is actually 27" fully extended so we can assume that they want at least 3" of engagement between the two pieces. If I remember right, there is at least another inch past that. In your case, you need a 12" shaft, 6" per side, plus 2" per side to get 4" of overlap which leaves you with 3.5" of collapsibility if you get everything perfect.

[Alponcho]

Thanks, I hadn't considered your point about not needing a telescoping shaft because the rack and column aren't in line with each other. Your math also makes sense too, it should be possible to shorten that shaft to 12" and have 3 or so inches of collapsibility left. Before you replied, I finally was able to get a hold of Borgeson tech support. The person I spoke to told me that there's an internal spring that I could run into if I cut the shaft too short and didn't recommend cutting it to 12". It's been a while, but I believe I took one of these apart at some point and I don't recall there being a spring inside. Or is my recollection off?

[dontlifttoshift]

I remember what looked like a tiny leaf spring but I didn't think that was in the shaft we are talking about.....maybe it is. It was just there to keep the two pieces from rattling.

I really would skip it though. The 1" side is going to need a new U joint and space is already tight on both ends. The larger diameter also makes the header fab more difficult.