Tapping a gear box- verify this please

[Mudstud]

1/4" 18 thread NPT, right?

 

[kennyw]

18 TPI is correct for 1/4 NPT. Your tap drill size should be 7/16 for Briggs Pipe Taps or 27/64 for Whitworth Pipe Taps. It is also best if you ream the hole using a reamer with a 3/4 inch per foot taper.

 

[Greg72]

Based on your spelling, I'd say the choices should be Duct, Masking or Scotch....

 

[kennyw]

You forgot electrical tape...

 

[Mudstud]

18 TPI is correct for 1/4 NPT. Your tap drill size should be 7/16 for Briggs Pipe Taps or 27/64 for Whitworth Pipe Taps. It is also best if you ream the hole using a reamer with a 3/4 inch per foot taper.

Thanks for the response. I'm swapping sector shafts right now for crossover. Since it's apart I'd like to drill/tap it for eventual assist. What are the most common fittings for rams so i can use the same fittings all around?

 

[kennyw]

I don't think there is any such thing as most common. You can get about 15 varieties of fittings from NPT, to SAE to JIC... Then there is British and Metric. From there you move into tapered, straight thread, o-ring, or flared variations.

 

[Mudstud]

Left a message for West Texas Offroad to call me back letting me know what fittings they use. I'll make mine compatible to theirs. Thanks.

 

[Mudstud]

18 TPI is correct for 1/4 NPT. Your tap drill size should be 7/16 for Briggs Pipe Taps or 27/64 for Whitworth Pipe Taps. It is also best if you ream the hole using a reamer with a 3/4 inch per foot taper.

So both are 1/4 taps? Just depends on what brand of TAP I use as to what size hole I need?

 

[gmc4cw]

save yourself some work. tap the top cap and end cap. Mine are tapped for 3/8 pipe.

you can piece together a setup much cheaper then West Texas. I have about $200 in my hyrdo assist. I bought a 2" ram, a 1.5" or 1.75" would be cheaper. you can get hoses made almost anywhere and they will be the right length for you instead of a generic length. tabs for mounting are just peices of metal.

here is mine. http://coloradok5.com/forums/showthread.php?t=201439&highlight=hydro+assist

 

[kennyw]

I think you can ignore the Whitworth taps... looking at it closer it appears to be a British standard thread form. The Briggs tap looks like it is the American National Standard. The two sizes I listed are only a 1/64" apart too... you probably won't notice the difference either way.

 

[Mudstud]

Thanks gents. good info. I'm just gonna drill and tap. The box is apart so it's an easy thing to do and it's cheaper. I'll stick with the Briggs Taps. Stopping by Home Depot today to get one. Hopefully they carry that kind, if not I gues I'll just use what they have.

 

[thedrip]

Anything labelled as pipe thread and sold in the US is going to be "briggs" also known as national pipe thread (NPT). Ive had trouble finding pipe thread taps at HD personally, if they have anything, it's usually 1/8". Not nearly large enough for hydro assist. I'm going 3/8" pipe on my box.