American Suspension clevis, what's the thread??

[Moespeeds]

I have to chase the threads on my inside (smaller) tube on my American Suspension springer. The clevis galled and left some aluminum in there, long story. Anyway, the clevis itself seems to have an acme thread on it? It's got a square side profile. Measures at 22mm x 1.6mm pitch. Where the hell can I get a tap for this thing, and does anyone know for sure what size this thing is? I brought it to a local machine shop and called American suspension with no luck.

 

[Five Five]

Well Moe.... I will thow an option out there that I would consider.....Muriatic acid (pool acid) will attack and desolve aluminum and whats cool about it is that it does not attack steels or stainless steels....we use this method here at work to strip out the aluminum thats galled up in our thread gages.

be careful with muriatic acid around chrome it strips it instantly upon immersion right down to the nickel plating...it does not attack the nickel plating... bright nickel plating has a slight brown tint to it after stripping the chrome..

use in a well venilated area.

:2thumbs:
"five"

 

[Moespeeds]

Tube is powder coated

 

[Five Five]

Even better... powder coat is a good resist to acid... shouldnt be a problem...just get a bucket put some acid in it put the end of the springer for about 30 minutes pull out rinse and dry...
PM me if you want to take this route and I can give you my phone number....walk you through it ...

 

[Moespeeds]

Thanks Five Five but I'm really leaning towards mechanically cleaning the threads, because I'm not so sure what caused the issue in the first place. AS has offered to take the tube back and re-tap it, and though it was my last resort, it looks like my only option. I'm just fed up with the never ending string of hang ups on this project, it seems I'm always waiting on someone else to get me something. I'm really an inch away from making my own clevis's and tubes in a standard thread!

 

[Five Five]

Try McMaster Carr...
Here is a linky you can browse there catalog

McMaster-Carr

 

[Staffy]

For all the business you've given Ted @ American Suspension, he should ship you a new tube - what the hell, its worth asking. 3rd set of tubes for you he should oblige (I think). Good luck.

(sorry don't have the thread size)

 

[alhall88]

Acme threads are at 15 deg (30 included) with a square bottom that matches the pitch. A number 5 acme will be a 5 threads per inch thread. A 1.6 mm pitch is not standard metric pitches are usually 1.25,1.5,1.75mm. Can you measure the od of the clevis? Your sure its not a standard thread like a 24 pitch? You can chase threads on your lathe if you know how. I can step you through it but we need to know the pitch at a minimum.

 

[Moespeeds]

I can make threads on the lathe, but I need a new gearset to do metric. It's definitely 1.6mm Acme, I verified it with a local machinist. It's a custom thread, probably so it's damn hard to make them yourself. I'm sure it's all done overseas anyway. The solution is to send it back to Ted, he has agreed to fix it for free. In the meantime I took two old tubes from my Big Dog setup, slugged them and welded them together to make one long tube. I'll cut that down, and force the bad clevis in there. It will get me through mockup so I'm not waiting on the new clevis/tube.

 

[alhall88]

It's hard to believe they went through all that trouble, I have never even seen a 1.6 mm metric gearset on any lathe that I ran in the last 30 years

 

[Moespeeds]

Machinist said pretty much the same thing Al. When I came up with 1.6 on the thread gauge, I thought for sure I was doing something wrong, so I took the whole mess over to the machine shop. AS claims they make the taps themselves. No big deal, Ted at AS stepped up and is sending me a new clevis and tapping the bad tube free of charge. In the meantime I've rigged up a temp tube for mockup, and came up with a pretty trick way of getting the whole front end lined up. I'll post pics when I get a chance.