Installing used Rails (Side Steps) Being a big pain in the a$$ - Need help sizing correct Bolt size

Hey folks.

So I have a new to me 2007 Tundra 4x4 Crewmax that being 4x4 is a little high for most of the family to get in and out. So from FB marketplace I got some used "Crewmax" sized side steps (rails, railings, side rails - whatever you want to call them). The guy I bough these steps from only give me the side steps and no hardware (install bolts). The brackets to mount were already on the side steps installed. So I figured I only need to get the side step bolts and bolt it up to the truck.

However installing them has been a huge PITA. The truck does have the existing bracket holes for the side steps, but it did not have the screws that went into those holes. So I did some Google search on the internet and Tundra forums which said initially said I needed a M8-1.25 x 25mm bolt for the bracket holes. I got me some M8-1.25 bolts and tried installing in the bracket holes. But i noticed the M8 bolts where bigger diameter than the hole. So what I did was to take out many different type of bolt size. M8-100, M7-1.00, M6-1.00 thinking its a different bolt size. The M7-1.00 size looked like it fit the size.

MIND you since the bracket holes where open all these years there were a little rusted (its a southern truck so not too bad). So I proceeded to clean them with brake parts cleaner/PB Blaster and one of the M7 bolts rocking it back and forth into the holes. They seem to have cleaned the holes up.

I then proceeded to install the side steps. (Bolt - flat washer - bracket - into hole did not use lock washer as I didnt have one). I first noticed the that some of the M7 bolts where not locking tight to the bracket. But I thought that probably how it is as long as they are in does not matter if they keep on spinning. After I managed to put all the 6 bolt into the bracket I stepped on the side rails, and it came crashing down. WTF. I initially thought I did'nt tighten the M7 bolts enough. or that the side rail brackets where not not in the correct hole alignment. So then I proceeded to just install the side rail brackets without the side rail. And again I noticed I could not get the M7 Screws tight into the brackets to hold. It was here when I thought I may have the wrong screw size.

Long long story short. I think I'h done F**ked up by threading M7 screws into rusty M8 size holes. Or maybe not. I am not too sure.. Either case I still want to put the side rails up.

- Could someone confirm what is the exact bolt side in those side rail bracket holes 1st?
- Do I need to have a lock washer in the mix to ensure the bolts just dont keep on spinning?
- What do you think are my options. Rethread the holes or am I used wrong bolts altogether. What am I doing wrong here?

Any help on this matter would be very much appreciated. I really need the sides rails up on this truck.

 

I removed my factory side steps recently. On my factory steps, the bolts that attach the brackets to the steps were identical to the bolts that attached the brackets to the truck. So remove on of those bolts and take it with you to the local bolt store to get it measured for exact size.

 

The M7 bolts are too small, you do need M8x1.25

Likely from being open to the world the holes are gunked up. You could sent a M8x1.25 tap into them carefully to clean up the threads. That’ll fix the problem.
Or know M8x1.25 is the right size and carefully start and thread the bolts in and out to clean the threads. Do this without the brackets first until they’re all clean.

 

Or take a trip a to your local Toyota parts dealer and find out what bolts they call for , hell there probably cheap enough there could get OEM replacement's for it.

 

@eccracer104 So you are positive that its a M8x1.25 hole size right? if you are sure then I'll go ahead and tap it to that size to ensure it works. I'll let you know what happens.

 

I’m 99% certain and would do this for my own truck if need be. This is a forum and I hold no liability if you work on your own vehicle and make a mistake.

I encourage you to look this up as well for your own confidence:

Toyota’s instructions refer to M8x1.25x20 (diameter, pitch, length)
And this can be found here -
http://toyotaparts.sparkstoyota.com/install/PT767-34160inst.pdf



These reference to a 2016 model year. While they’re the same, for added confidence here are the instructions from Westin which reference 2007-2017 model year fitment. Unfortunately they don’t list the size beyond M8
https://www.westinautomotive.com/images/ePIM/original/75-3032.pdf



So based off this info I feel confident in suggesting an M8x1.25 tap to clean the threads.

YMMV.

 

@eccracer104 you are the man.. my holes were quiet dirty which is why I thought the m7 screws were what worked for me. Anyways I went to autozone. Got myself a die tap loner kit. Tapped the holes with a m8x1.25 kit. From there the M8 screws went up like butter. Installed the side steps from there.. But may where they a PITA to get up and installed.

 

Picss?

 

Pics.. l'll take some and sent them out.