GM hood hinge springs

[RAS68]

This post is about my experience with hood hinge springs on my 68 SS. I know there are some older posts on this subject but I think this warrants a new post to share some part numbers. When I refreshed/restored my 68 SS in 2017 I thoroughly cleaned and painted my original hood hinges. I bought and installed new reproduction hood hinge springs for SS hood application. These were made by Classic Industries and had 28 coils. The hood always sagged a little. I thought it might be due to the somewhat worn original GM hinges. Recently, I decided to try GM hood hinge springs part number GM 3848272. The GM springs look pretty much identical to the reproduction springs. I installed the new GM springs and now the hood opens easier and there is no sag at all! I am very pleased. The GM springs are not much more than the repro SS hood hinge springs but they made a world of difference. I recommend using the GM springs that you can get from any GM parts dealer. Also, I used the washer trick to remove and replace the springs - that method works very well and its pretty easy. I hope someone finds this information useful.
Allen

[ZLP955]

Didn't know they were still available from GM..... thanks!
BTW have you read the hood hinge spring info here?

[68camaroz28]

I think another key point is many cars can use the original hood hinge springs as in many cases they are not pitted with rust. A good soaking in Evapo-rust and oiling or some other rust preventative is all that is needed in many cases. Our 68 utilizes the original springs and they look like new.

[Mike S]

 I replaced the 67 hood springs with GM springs (28 coils) recently and they look and fit exactly as the originals.
The finish is an oiled phosphate. The originals would allow the hood to slowly close about 1/2 way.

Mike

[67 nut]

Mike,

(Don't want to steal this thread) Are those new GM springs in a zinc phosphate (silver), or in the manganese phosphate (dark gray)?

[Buzz67]

I think another key point is many cars can use the original hood hinge springs as in many cases they are not pitted with rust. A good soaking in Evapo-rust and oiling or some other rust preventative is all that is needed in many cases. Our 68 utilizes the original springs and they look like new.

I'll echo Chick's advice. That Evapo-rust stuff is a restorer's magic elixir! I soaked my rusted driveshaft inside a PVC tube of Evapo-rust overnight and it came out looing like new! And the painted stripes (not even visible before) hadn't been chemically removed and were now visible for documenting and repainting! Great Stuff!!

[Mike S]

Mike,

(Don't want to steal this thread) Are those new GM springs in a zinc phosphate (silver), or in the manganese phosphate (dark gray)?

  They were covered in a thin oil when removed from the wrapper and the hue matched the hood hinges exactly. It's hard to tell what color but I would say dark gray. As I understand it, GM used phosphate on parts, which provides a good base for a followup oil treatment. This was a low cost method of rust control. Yes, phosphate a part and rinse and dry it and it is a tone of gray. But put an oil on it, which I believe the factory did, (I use Dri-Touch) and that gray changes. After it is on for years it will turn to a sort of olive green, like a firearm.
 

Mike

[169INDY]

GM Part number?

[Sauron327]

Because the springs are spring steel, they have a different hue and value than the phosphated hinges.

[Mike S]

GM Part number?

The GM P/N is 3848372 and I paid $30 for the pair.
It is a 28 coil spring. Attached is a picture of the spring in its packaged oil finish. It matches the hinge but in the photo it appears slightly darker.

Mike

[169INDY]

GM Part number?

The GM P/N is 3848372

Thank you mike.

JIM W

[Sauron327]

GM Part number?

The GM P/N is 3848372 and I paid $30 for the pair.
It is a 28 coil spring. Attached is a picture of the spring in its packaged oil finish. It matches the hinge but in the photo it appears slightly darker.

Mike

Please explain how metals manufactured with different  procedures produce the exact same hue and value in regard to springs and hinges.

[Mike S]

Scott,

  What are you talking about?  The picture speaks for itself in regards to hue between the spring and hinge. Looking at it in person they look the same. The photo shows a slight variance.

Mike

[Buzz67]

I decided to have my hood springs phosphated right along with the hinges, hood release, lower pulley, just to keep the rust at bay. I knew it wasn't technically correct, but just wanted them protected from future rust.

[68camaroz28]

Scott,

  What are you talking about?  The picture speaks for itself in regards to hue between the spring and hinge. Looking at it in person they look the same. The photo shows a slight variance.

Mike

Mike, I think Scott is referring to the difference in material with one being spring steel and other using a phosphate chemical finish. The spring steel has a smooth texture and looks like it is, spring steel. I understand your point as they do have a similar dark appearance but understand Scott's point as well. Here is what our 68 original hood springs looked like after some evapo-rust and protection but again, they had very little in the way of rust. And then one of our restored hood hinges with a spring attached. How close in darkness I think we can agree depends on the color/type of the phosphate/manganese used. Nice example shown Mike!

[Mike S]

Hi Chick,
  Your hinge assembly looks more light gray than mine. Is yours oiled or dry? Mine is oiled and it turned (over time) from that gray like yours to a darker gray in the photo, which matches the hue of the spring on my car when viewed with the eye. The camera shows otherwise and that is likely due to the round shape of the spring reflecting the flashes light in a diverging pattern whereby the flatter shapes of the hinge reflect it back more to the lens (astrophotography is my passion so I'm familiar with light behavior)
  If you ever parkerize a firearm (it is the same as phosphating) they too tend to darken over time when oiled. It is likely the oil causing that reaction. Thanks for the reply!

Mike

[Tx-Z 302]

So what's this washer trick for spring replacement?

[68Zproject]

Lower the hood enough to insert washers between the springs. Raise the hood and it should have enough slack to pull out.

[Sauron327]

Scott,

  What are you talking about?  The picture speaks for itself in regards to hue between the spring and hinge. Looking at it in person they look the same. The photo shows a slight variance.

Mike

I've noticed different hues when comparing spring steel and non spring steel. That is all. Photorealistic airbrushing is a field with which I am familiar.

[Sauron327]

So what's this washer trick for spring replacement?

You do not need to use washers. 
Every make and model I've done was accomplished with a vise and a hook to remove and install the spring.  Piece of cake. No washers.

[clm69z28]

I parkerized my hood hinges along with the hood latch and some other underhood parts about 7 years ago, and the finish is still holding up and I am not too far from ocean.

[BLee67]

GM Part number?

The GM P/N is 3848372 and I paid $30 for the pair.
It is a 28 coil spring.

It doesn't look like that part number is good anymore.  I did find #3848272 which is also a 28 coil spring for $14.62 each.  I hope it's the same one.  There are also some springs listed on ebabe with the same 3848272 part # which allegedly also fit Impala, Camaro, Chevelle and Firebird. 

BL

[Sauron327]

The GM part number is 3848272. I have them in stock. And yes they are used on multiple makes and models. I deal with HoodHingeRepair. Willie has rebuilt countless hood and door hinges for me. Not to mention repairing damaged hard to find hood latches for certain models.

[hugrz28]

Has anyone been able to find, source the hood springs for the ZL2 Cold Air Hood? The original GM Part # is 3877203.