So when Mazda put my reman in last year they broke the two bottom throttle body studs and replaced them with bolts. The other day I was installing a boost gauge and in removing the intake elbow discovered that only one of the bolts was there. It turns out that when Mazda did my oil change a few months ago they striped the threads in the bottom front hole and instead of fixing it they just left the bolt out.

So my question is, does anyone know the thread pitch for the throttle body studs? Or if not what size of helicoil do I need (thread pitch)? I may put new studs in or just buy new 10mm bolts and use them instead.

 

man those studs break all the time...I broke one of mine and asked about it and a ton of other people said the same thing happened. i just used a bolt to replace it once I was able to get the broken half out of the way. I don't know what thread size it is but you may be able to get away with using a bolt and putting a nut on the other end of it...I can't remember if that stud hole goes all the way through or not?

 

Autozone has a replacement that is the exact size but is just a bit longer but it works fine. The Sku # is 329306.

 

widebody2:
Unfortunately it is where the front bottom stud goes that is stripped, this is the one whose hole does not go all the way through the throttle body.

Bucrx7:
Thanks for the part number. I am pretty sure Autozone is the same as Advance Auto Parts, which is what is here. I will check them out tomorrow and see if they also have a helicoil kit to fit this stud.

Thanks for the help .

 

If the aluminum is stripped you will need to heli-coil the hole..( make new threads) not just by tapping but putting in the heli-coil insert. They are sold as kits, they come with a number of inserts( buy the correct size, 6x1.00mm) Most come with a tap and the locating tool for the insert. You will need to check the package for the drill size needed.

Basically you are drilling the hole larger, tapping it, inserting the heli-coil, and then insert the new stud( also a 6x1.00)

Hope this helps you out. It sounds more complicated than it really is. Just put some paper towels in the TB to keep any shavings out of the engine. Also depending on the size of your drill you may need to pull the UIM off or just the TB. Just to make it easier

 

BigIslandSevens:
Thanks for the info on the helicoil and the stud size, this is what I will do.

 

In five years of working on other peoples engines, we have never strip any of those ,and only broken prior damaged other fasteners on the cars.

If everyone followed Mazda's torque standards which is in their manuals, most of this will never happen. If after removing any fastener that is slightly damaged or questionable, reset/clean them up with either a tap or die. Sears sells two sets of metric dies and taps and are a must to be a good mecahnic!

"It turns out that when Mazda did my oil change a few months ago they striped the threads in the bottom front hole and instead of fixing it they just left the bolt out."

This has nothing to do with an oil change, explain that!

 

I ask Mazda after discovering the bolt missing and they told me that they remove the intake elbow from the throttle body to put the new oil filter on. The service desk guy was supposed to tell me that the threads were stripped and that there was no bolt there.

I guess my Mazda dealership should follow your advice and use there service manual, oh ya I forgot they don't have one for a 1994 RX7. I had to give them copied pages out of mine when the put my reman in.

 

Never take a RX-7 to a dealer or anyone except when absolutely necessary.

They will always mess things up.

That dealer sucks.


You don't need a RX-7 manual. Most fasteners torque values are the same for all Mazdas for the same size fasteners.

The small 10mm nuts, and there studs/bolts go to about 86 inch pounds middle of the range. That is barely over 7 foot pounds. Easy to break by hand!

Any good Mazda mechanic should know that.