Tapping lower front spring perch

[UKTJ]

I believe the correct way to fit bump stop extensions in the front is to drill and tap the lower spring perch and then bolt chosen means of extension to the perch.

As I have never tapped a hole before this is a bit daunting. How easy / hard is it to tap the spring perch? How hard is the material the spring perch is made of / does it require a particularly industrial tap to do it? What size bolt do people generally use? How big a hole do I drill before tapping?

Apologies for the very basic questions, any help much appreciated. I really want to avoid screwing this up.

 

[MichaelGH]

A standard tap will get the job done. Use the proper size drill bit and have at it. Mild steel drills and taps very easily in my experience. Once you do the first one the second one will go much faster. A lot of videos on YouTube for guidance as well. Good luck!

 

[someguysjeep]

1/2-13 is pretty common for this application, IIRC. a 27/64 bit would give you the hole you need for tapping.
getting the tap started is the key, you need it to go in straight.

the spring perch is 1 of the thicker chunks we have to make holes in, but it'll drill pretty easy, the tap will take some effort to get started but isn't hard. as you turn the tap in if you feel it lock up reverse the motion to relieve the pressure and then continue until your through. and use some oil to lube the tap.

 

[LONGJP2]

As I have never tapped a hole before this is a bit daunting. How easy / hard is it to tap the spring perch? How hard is the material the spring perch is made of / does it require a particularly industrial tap to do it? What size bolt do people generally use? How big a hole do I drill before tapping?

First you'll have to decide if you want standard or metric.
A good set should have a chart for what size hole to drill.
The first (complete) turn or two needs to be held straight and with a little pressure. After that it will pull itself in.
Once it's started, reversing a quarter turn for every 1/2 turn forward allows the thread that you're cutting to break off and fall into the flutes instead of jamming up the cutter.
Lubricate to help the cutting, add some grease if you need to catch the metal filings.
I'm sure there's tons of videos out there.

 

[pagrey]

Big threads are easy to cut. That's mild steel so even a cheap tap will cut it. Everybody else covered the important bits, firm pressure to start, get it straight and don't do it dry. Using a bolt about the same size as your shock mount bolts seems like it would be fine. 1/2" is great too, it can double as a recovery point in a pinch.

 

[freedom_in_4low]

I bought Zone bump stop extensions, which conveniently came with a thread-tapping bolt to cut the threads. I later switched to Currie/Rockjock bumps which used a larger bolt so I had to drill and tap it larger. I thought providing the bolt was pretty well thought out because it's cheap and takes care of the folks that don't have a tap set laying around already.