TB Screw Size (Searched, no luck)

[Artago]

Hi all,

I've done some searching and I can't find the answer. Maybe someone with CAPS can help me out.

I need to replace the Throttle Body screws holding the top and bottom half together.

I think they are M5 x 0.7 x ??

Anyone know for sure?

Thanks,
Tom

 

[NHerron]

Which screws do you need, or are you talking about the mounting bolts for the T/B to intake manifold?

 

[Artago]

The 5 screws that join part 07704 and 07707. They are long about 60 - 80mm.

I guess it's 07792T and 07792U

 

[NHerron]

07792T - MF350051 - x1
07792U - MD614416 - x4

Unfortunately, it does not list thread pitch/size.

Do you have a pitch gauge? They come in tap/die sets a lot.

I have a spare throttle body sitting in the garage, I can go check it out with my pitch gauge

 

[Artago]

07792T - MF350051 - x1
07792U - MD614416 - x4

Unfortunately, it does not list thread pitch/size.

Do you have a pitch gauge? They come in tap/die sets a lot.

I have a spare throttle body sitting in the garage, I can go check it out with my pitch gauge

That would be effing awesome. I need M? x ? x ?. Thanks!

 

[NHerron]

It's actually a standard size, I guess the decision was up to Mikuni on that one

I double checked because none of my pitch gauge fit perfectly, the closest one was 10-32. So I took a 10-32 tap and tapped a 10-32 sample hole in a piece of scrap metal. Perfect fit for the screws. And the tap also fit perfectly in the original TB hole. And good thing I had a spare TB around because I damaged the Philips head getting them out. I'm guessing that's why you're replacing yours? With that experience, I think I'm going Allen head bolts when rebuilding my TB in a couple months.

Anyway here is the specs

4 screws are the same length (07792U - MD614416) and they measure a #10 thread diameter x 32TPI x 1.37 inches in length

The short screw (07792T - MF350051) is .7 inches in length

For reference, the closest to metric threads I got was M5 x .8.

 

[007jimmy]

I used the screws that hold the ISC in for reference on my TB. They are the same pitch threads.

 

[Artago]

I took the old screwa down to a hardware store and it looks like they are M5 x 0.7mm x 35mm. They only had 40mm so i stuck in 3 M5 wahers to space it out. The last bolt is shorter.

 

[ed1380]

It's either m5x.7 or m5x.8, most likely the later.
You can check using the MDP sensor bolts. They're m5x.8

 

[Artago]

It's either m5x.7 or m5x.8, most likely the later.
You can check using the MDP sensor bolts. They're m5x.8

Not sure if it's .7 or .8. I just took one of the old bolts down to the hardware store and matched it. The bins did not label the thread pitch but they were all the same.

 

[NHerron]

It's most likely M5 x 0.8 due to everything else on the car is metric. It's not a 0.7 pitch.

But in reality, 10-32 is so close, that the two are interchangeable no problem.

Why?
M5 thread diameter is .1960" and a #10 machine screw thread diameter is .1900". So six thousands difference is really nothing to think about when considering the machining tolerances of most hardware, besides ARP or other high dollar hardware.

10-32 is 32 threads per inch.
A 0.8 pitch translates to 31.75 threads per inch (25.4 / 0.8 = 31.75)
Again, very close and unnoticeable.

This is true for the ISC and TPS screws as well.
The part numbers listed (07792U - MD614416 and 07792T - MF350051) are the same for any GST/GSX from 1990-1999


I found no other threads on this anywhere. So hopefully this thread has enough tags to help someone out in the future.

 

[drewbuddy]

you can take the bolt to a NAPA or bumper to bumper(if they have one in Van) or similar shop and they should have a gauge to tell you what size it is. I've done it here in Edmonton.