C2>Why The Three Holes On Top Of The Frame Cradle?

[Larry E.]

Just Curious: Why are there 3 holes on the top of the frame cradle just below the Engine Damper
(Picture Below) Perhaps
for factory assembly purposes to hold this part? Just a guess. Thanks>Larry

[Duke W.]

Re: C2>Why The Three Holes On Top Of The Frame Cradle?

Your "guess" is quite possible. The start of the assembly process was a large fixture that held the frame upside down, and this is how most suspension components were installed. Precision mounting was required because rear toe was set at this point.

I know John Hinckley had a presentation that described this assembly process, and it might be here on the TDB or at least he discussed it in some threads.

Duke

[David Z.]

Re: C2>Why The Three Holes On Top Of The Frame Cradle?

Here's an article on chassis assembly by John Hinckley from the Corvette Enthusiast magazine (2006).
Dave Z

[Mark F.]

Re: C2>Why The Three Holes On Top Of The Frame Cradle?

Here's an article on chassis assembly by John Hinckley from the Corvette Enthusiast magazine (2006).
Dave Z

Hi Dave,

Good read and thank you for posting.
Do you have access to all of John's Corvette Enthusiast articles ?
I subscribed to Corvette Enthusiast from the 1st issue on until they ceased publication (can't remember when that was, but it was a good rag...sorry it went away).
Were pdf's ever made and available via some venue ?
I can't find anything on the web

[Mark F.]

Re: C2>Why The Three Holes On Top Of The Frame Cradle?

Just Curious: Why are there 3 holes on the top of the frame cradle just below the Engine Damper (Picture Below) Perhaps for factory assembly purposes to hold this part? Just a guess. Thanks>Larry

Larry,

My guess is they may have been fixture locating holes when the frame was being assembled by A.O. Smith.
That crossmember aligns the two frame side rails and based on the bead size; speed; and heat welding created - it needed to be firmly and accurately secured before welding could take place.

John Hinckley's C2 Assembly Process Presentation (available in the Database of Restoration Documents [DoRD] Sticky Post) doesn’t say anything about those holes – probably because the frame arrived that way and he was only explaining what they did at St. Louis in his presentation. Pictures I have seen of the Frame Upside Down Line (FUDL) don't seem to show those holes filled with alignment pins or anything else I can see - but that's not to say pictures that may have been taken at different stations up, or down the line might have...who knows ?

Also, we might say after rolloff, delivery and years of driving they may also serve as drain holes to prevent premature rust out of the cradle My wife had an MKZ that the cradle rusted so bad it failed PA state inspection, but was replaced under warranty.

[Duke W.]

Re: C2>Why The Three Holes On Top Of The Frame Cradle?

What's a "MKZ"?

Duke

[Mark F.]

Re: C2>Why The Three Holes On Top Of The Frame Cradle?

What's a "MKZ"? Duke

It was a Ford product (dunno if Lincoln had formally "split off" from them or not)

https://www.lincoln.com/luxury-cars/mkz/

[Richard M.]

Re: C2>Why The Three Holes On Top Of The Frame Cradle?

Just Curious: Why are there 3 holes on the top of the frame cradle just below the Engine Damper
(Picture Below) Perhaps
for factory assembly purposes to hold this part? Just a guess. Thanks>Larry

That pickup looks like mine and that frame looks like the one I did back in '15. BTW it's a '67. Those looks like my trees in the background too!

HaHa that's funny Larry. I'm glad you used that photo. Must've been from that long build thread I did back then. Gosh that was a long thread with so many photos.

Anyways, I always wondered about those holes too. Maybe alignment for the chassi build as mentioned, or maybe for the huse metal bending jig at the frame fabrication facilty(AO Smith iirc), or maybe even designed in "vent" holes so the air can pass through too.

Or all of the above?

Rich

[Larry E.]

Re: C2>Why The Three Holes On Top Of The Frame Cradle?

Thanks to all for the response. Another guess from me>Could those holes in anyway
"strengthen" this cradle? vs. one with no holes?(By relieving the stress) With all that weight that goes through that area I would
think that cradle flexes to some degree even though very small. Maybe we will never
know. Larry

[Mark F.]

Re: C2>Why The Three Holes On Top Of The Frame Cradle?

...Anyways, I always wondered about those holes too. Maybe alignment for the chassi build as mentioned, or maybe for the huse metal bending jig at the frame fabrication facilty(AO Smith iirc), or maybe even designed in "vent" holes so the air can pass through too. Or all of the above? Rich

https://www.google.com/search?sca_esv=65b627a4699ea87d&rlz=1C1VDKB_enUS1040US1040&q=production+automotive+frame+stamping+fixtures&tbm=vid&source=lnms&prmd=sivnmbtz&sa=X&ved=2ahUKEwjNxJyd2suFAxV9kYkEHU2LBfgQ0pQJegQIDhAB&biw=1745&bih=828&dpr=1.1#fpstate=ive&vld=cid:dbe15257,vid:FQ7S66jq7EY,st:0

[Mark E.]

Re: C2>Why The Three Holes On Top Of The Frame Cradle?

Thanks to all for the response. Another guess from me>Could those holes in anyway
"strengthen" this cradle? vs. one with no holes?(By relieving the stress) With all that weight that goes through that area I would
think that cradle flexes to some degree even though very small. Maybe we will never
know. Larry

Flanged holes may increase rigidity, but the edge of holes are also prone to fatigue cracks. My guess is they're locating points for a jig or fixture. Double as drain holes too.

[Bill M.]

Re: C2>Why The Three Holes On Top Of The Frame Cradle?

Thanks to all for the response. Another guess from me>Could those holes in anyway
"strengthen" this cradle? vs. one with no holes?(By relieving the stress) With all that weight that goes through that area I would
think that cradle flexes to some degree even though very small. Maybe we will never
know. Larry

The holes are stress risers (increase chance for a crack). My guess is that the big hole accurately locates the crossmember in the jig that welds the frame and the small holes keep the crossmember square to the siderails.

[David Z.]

Re: C2>Why The Three Holes On Top Of The Frame Cradle?

Mark,
I just sent you a PM.
Dave Z

[Mark F.]

Re: C2>Why The Three Holes On Top Of The Frame Cradle?

Mark, I just sent you a PM. Dave Z

Hi Dave,

I have no PM from you in my inbox...checked twice over the past 1/2 hour.

just click on the email link and send me one if you care to

[David Z.]

Re: C2>Why The Three Holes On Top Of The Frame Cradle?

Email sent but it lost the colored text of messages from John re: his CE articles.
Send me an email address and I'll send that info along.
The PM turned out to be 396 characters too long so it did not send.
Thanks
DZ