GM#3738505 differences

[Ian S.]

Hello,

When did this lower control arm shaft change from a flat bar shape to an almost I beam shape?

Thanks,

Ian

[Joe L.]

Re: GM#3738505 differences

Ian-----

That I can't tell you. However, I can tell you that the GM #3738505 forging and GM #3749296 finished part manufactured from it have been around for a LONG while. It was first used on 1958 Chevrolet passenger cars and its use continued through 1964 passenger cars. So, it was around for 5 years before it ever appeared on a Corvette.

My original owner 1969 with known original shafts has the flat bar style forging. So, I presume that this style was used until, at least, 1969. However, it's possible that the 2 styles were used coincidentally. Pretty much, one of 2 things had to have happened here:

1) the original blueprint for the part provided that it could be manufactured either way. In which case, different suppliers may have made it differently;

2) the blueprint was revised at some point. In that case, only those parts made after the revision would have the "I beam" configuration.

The SERVICE replacement parts sold over the last 15 years, or so, have been of the "I beam" configuration. I presume that these were also used in PRODUCTION, too.

What we need is some folks with original 63-82 Corvettes to report in. Checking this configuration is very easy; a glance under the front of the car will quickly reveal the configuration. I'm curious, too.

[Joe L.]

Addendum

I should also have mentioned that the NOS shafts that I have [none for sale], some purchased well over 15 years ago, are all of the "I beam" design. All have the "GM" trademark forged on them and all have the 3738505 forging number, too.

[Art A.]

Re: GM#3738505 differences

Joe, my 65 is the I beam style and my 82 is the flat bar style.

Art

[Joe L.]

Re: GM#3738505 differences

Art-----

That's interesting. That may be an indication that the 2 different styles were used interchangeably over the years.

[Patrick H.]

Re: GM#3738505 differences

Your 82???

Since when? Was it in hiding in late June?

Just curious.

Patrick

[Art A.]

Re: GM#3738505 differences

I told you guys that I didn't show you all of my "stuff"----actually you saw it but you didn't recognize it.

Art

somethingsarebetternotarticulatedmaybesomedayiwill tellyouinperson

[Patrick H.]

Re: GM#3738505 differences

Now ya got me. Saw it but didn't recognize it???

I don't "recall" seeing anything on the island that remotely looked like a 1982 Corvette. I'll have to find out the punch line later.

Patrick

[Patrick H.]

Re: GM#3738505 differences PS

BTW, the original one on the right side of my 71 is flat, the replaced one on the left is "I-beam" shaped, FWIW.

Patrick