throttle linkage

[egchewy79]

Looking to make my own throttle linkage for another car project.
I was planning on using an aluminum tube and tap the ends, similar to the Forte linkage
Seems that common thread sizes for the throttle links/studs are 1/4"-28 and 1/2"-20.
My question is that with the aluminum tubing, the wall thickness is rather thin, 0.035".
will I be able to tap that and still have enough strength in the tube?
does anyone know the diameter of the Forte linkage and the wall thickness off hand?
I'd measure myself but the cobra is on the lift w/ my other non-mobile project under it at this moment.

[Jonathan D]

Forte linkage is .075 wall thickness and .357 overall

[Jim1855]

edgchew79,

At .035" I don't think you'll have sufficient wall thickness to tap the tube with 1/4-28. Buy some and try it. 1/2-20 seems rather big for the task.

I built my linkage using P/N 6058K32 from McMaster-Carr. Quick-Install, External Spring, 1/4"-28 Thread

The "rods" are 1/4-28 stainless threaded rod. Worked well in previous cars and seems to work in the current from the testing I've done. Also built the linkage arms, main rod and used Internally Threaded Ball Joint Rod Ends for the supports.

Jim

[egchewy79]

edgchew79,

At .035" I don't think you'll have sufficient wall thickness to tap the tube with 1/4-28. Buy some and try it. 1/2-20 seems rather big for the task.

I built my linkage using P/N 6058K32 from McMaster-Carr. Quick-Install, External Spring, 1/4"-28 Thread

The "rods" are 1/4-28 stainless threaded rod. Worked well in previous cars and seems to work in the current from the testing I've done. Also built the linkage arms, main rod and used Internally Threaded Ball Joint Rod Ends for the supports.

Jim

thanks jim.
female ends on the linkages w/ a threaded rod makes more sense than male linkage ends and tapping the tubing. I think I'll go with this idea.

[Jeff Kleiner]

Eugene,
In my opinion 1/4" tubing is really not enough. Tap drill for 1/4-28 is #3 or 7/32" which is .218". That only leaves .016 for a wall thickness. I suggest that you start with .375" O.D. tubing with a .095" wall and an I.D of .185". You can then run a #3 or 7/32 drill into the ends and tap for 1/4-28.

https://www.onlinemetals.com/en/buy/aluminum/0-375-od-x-0-095-wall-x-0-185-id-aluminum-round-tube-2024-t3-drawn/pid/12793

Cheers my friend!

Jeff

[egchewy79]

Eugene,
In my opinion 1/4" tubing is really not enough. Tap drill for 1/4-28 is #3 or 7/32" which is .218". That only leaves .016 for a wall thickness. I suggest that you start with .375" O.D. tubing with a .095" wall and an I.D of .185". You can then run a #3 or 7/32 drill into the ends and tap for 1/4-28.

https://www.onlinemetals.com/en/buy/aluminum/0-375-od-x-0-095-wall-x-0-185-id-aluminum-round-tube-2024-t3-drawn/pid/12793

Cheers my friend!

Jeff

that was exactly my concern, Jeff.
I think I'm going to Jim's idea of using a threaded rod instead of a tapped aluminum tube. This also allows me to order everything from one place (Mcmaster carr) as I wasn't able to find aluminum tubing with a thick enough wall thickness there.
This truck isn't going to win any beauty pageants, so I'm not worried about the exposed threaded rod look.

[Rdone585]

You could cover up the exposed threaded rod with aluminum or SS tubing. Just use a diameter slightly larger than the threaded rod and add epoxy to hold it in position and keep it from rattling. Perhaps even capture it with nuts on each end.

[Jim1855]

I've thought about heat shrink or poly hose once the assembly is finalized. But from past experience the threaded rod never bothered me. You can wire brush the SS rod to pretty it up. I have also had to bend the rod to clear an air filter, worked just fine.

What I find appealing about the SS threaded rod is it's cheap, easy to cut to the desired length and has some adjustment in the swivel ends. You'll need check nuts to lock the pieces together. The swivel ends are easy to pull off the ball studs if necessary.

Jim