Belleville washers

[Juro]

The four center bolts on the intake manifold include Belleville washers.

What is their purpose? There are two per bolt.

[3X00-Modified]

um... never heard of this type of washer being used on the intake... I'm guessing someone put those there and they weren't there before. Especially if there are two per bolt... GM would never do something like that.

[Asylum]

Ya that is something you would never see on our cars.

On an Intake manifold? WHY?

[Juro]

Service Manual shows them here:

service manual.pdf

(642.71 KiB) Downloaded 161 times

service manual2.pdf

(552.21 KiB) Downloaded 178 times

[Asylum]

Well throw the damn things away. You don't require them!

There is absolutely no pressure or force there for that requirement.

Both Jon and I have quite a bit of experience with these engines, and they are not required!

[Juro]

What about that big speech about GM engineers?

[3X00-Modified]

I guess it would have helped to identify lower intake manifold... Would have made a bit more sense.

And to add to it if it's in the manual then why are you asking about it?

The lower intake is held down with 4 long bolts on the 3x00 motors and there is only a single washer that's center is rubber lined... The dual stacked washes is what made me think it was not an original item.

[Juro]

"intake manifold" per Service Manual

Curious

again, Service Manual shows two per bolt

[3X00-Modified]

Yes there is an UPPER and a LOWER... Clarity on what your describing can sometimes help eliminate confusion.

And once again I say... if your going by the "book" why are you asking about them... Just use them.

If you want to know why they are used then just look up what they do...

https://en.wikipedia.org/wiki/Belleville_washer

[Stencil]

If I recall correctly, my 2.8 and 3.1 engines had the dual washers on the lower intake manifold as well. I don't recall seeing them on the 3x00 setups.

[CorvetteBeretta]

Mine have 2 also and all the extra bolts I have 2, I've never changed them.