I want to make some SVA legal track rod arms for my new project. My first idea was to weld threaded bosses from McGill Motorsport into 1" seamless tube. My rod ends would then screw into the tube.

My project has a track width of 1.15m (overall width is 1.3m) and the wishbones go almost to the centre of the car. To avoid bump steer, the track rods go almost to the centre of the car too, so a conventional rack and track rod ends are a no-go.

A couple of people on here said that welded track rods would be an SVA or MOT fail. Not that these are "cut and shut" track rods.

My second idea was to get some tube with an 11.4mm or smaller ID and tap 1/2" UNF threads into the ends. I've just had a quote for 3/4" 8 SWG steel. For a special order I'll have to but a 6m length. £55 inc VAT. Its a bit steep, expecially as I only need about a metre of it.

So, what are peoples opinions on welded bosses, or other ways to make my track rods?

can't say I 1200% follow what you are trying to do.

the rack muse have track rods? so you wnat really long track rods? Can you not may long externsion? simple way would be to take a thick walled tube and tap the appropriate sided thread.

you would need track rod ends with a mlate thread at other end - if you know the taper, get down to local auto parts place and look in their catalogue as one of them lists this info.

I'm using rod end bearings at each end of the arm. The eye of the rod ends at the outer end will bolt to the steering arms on the wheel uprights. The rod ends at the inner ends will bolt to an arm that makes the steering movement.

I want a tube that is threaded 1/2 UNF at each end, LH at the one end and RH at the other. Either I weld the threaded insets into a 1" tube or I get some 3/4" thick wall tube and tap the ends.

The problem is that 3/4" 8SWG tube will cost me £55. The cheaper welded tubes, it has been suggested, may fail SVA / MOT.

I have definitely lengthened my steering column by welding tube into the middle of the donor column - as, I'm sure, have many others.

So I can't see why you can't make your track rod arms by the first method, welding threaded bushes into steel tube.

Obviously make a very good job of it, ensure plenty of weld area and mechanical locking of the two parts but I think it'll be fine.

Thanks Jag. That's what I wanted to hear. What do you mean by meachnical locking?

I was thinking of welding round the outer edge and have 3 puddle welds into the body of the insert.

Your puddle weld suggestion should be fine.

The other way would be to cut a slot, maybe 3mm wide and 25+mm long, along the length of the outer tube. Then insert the threaded bush and weld around the neck of the tube and along the slot.

The idea is that even if the weld does break away from one part it has a mechanical lock as well, which should hold it for a bit longer - kind of like a failsafe idea.

Puddle welding will do exactly the same thing.

[Edited on 10/1/08 by JAG]

The setup you describe is pretty common in fact if you can find one a complete Hillan Imp rack and TRE would do the job.
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Originally posted by smart51
Thanks Jag. That's what I wanted to hear. What do you mean by meachnical locking?

I was thinking of welding round the outer edge and have 3 puddle welds into the body of the insert.

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