Threads rusted on cab running board holes

I went to put running boards on my tacoma and found that the threads were so badly rusted that the stock screws (m8x1.25x25mm) would not even go in. I was able to get a m7 screw to go in which is a tiny bit smaller and it actually tightened up but was a little loose. I was thinking to use some kind of adhesive to stay secure. I was debating using loctite or silicone...what do you guys think?

Other option was to try to rethread the holes using a tap set.

 

Chase the holes with a tap first then be sure to use anti seize on the mounting bolts.

 

tap

 

Thats a good idea. Use the same size tap as the M8 bolts or go higher?

 

Since you know the original size, I'd re-tap with that. If they're real bad, use some cutting oil.

 

I had to chase the threads with a tap when I mounted my boards up-- but on just one of my holes on each side that was very rusty. The others were clean and the bolts threaded through great.

 

It is clear I don't know a whole lot ... but this might help.

I had this same problem on my 2005 Tacoma. I bought a small wire brush in the shape of a Christmas tree, soaked it in rust removing lubricant (can't remember what brand I used but picked it up at Autozone), and twisted it in the whole and spun it around for awhile. I then got another liquid that I rubbed on the bolts with another product and they slowly threaded right in and those holes were pretty rusted. Might not apply in your case but in case it does I wanted to share. I found the metal brush and the lubricant worked pretty well. Might be worth considering.

 

To clean up existing threads, use a chaser. To cut new threads use a tap. There is a difference.....

 

this worked great. Cleaned the holes out after with WD-40. I also got the cheapest running boards on eBay and they’re def not high quality but I like em. 4” running boards look pretty good. I thought they were gonna look too wide but they don’t and it’s also pretty easy to get in and out of the truck with em.

 

happened to me, some wd 40 and carefully re-tap

 

Nice! Those don't look bad on there at all. They've got a good length and position between the tires. As long as they serve their purpose and you like them, I say rock em.

 

A tap will work just fine.