1970 Trans Am 1 year only Hood Hinge Springs / Questions??
 

Would it be correct that the 70 Trans Am used the smaller springs on the Hood Hinge? Same as the earlier Firebirds and GTO's? Then switched to the larger Diameter Spring in 1971?
1970 Parts Book calls for #3848272
1971-75 calls for #3907626
I have a set of Original 1970 ONLY Hinges here that have the larger Diameter Spring. Wondering if they switched to LARGE spring at some point later in the 70 model year due to the "Hinge Issues" they were having in 1970.
Also as we know the 70 ONLY hinge has the small welded on reinforcement piece due to the problems they were having. Question: Was this change made DURING the model year or was the "problem" discovered and changed BEFORE Production Started?
Any Thoughts from the 70 Trans Am experts on this Forum are appreciated.
RA

IIRC the design did call for the smaller spring, but once tested on prototypes , the larger spring was used. This same spring was used on Glass hoods ( Formulas) too.
So, ALL 70 birds got same hinges and springs.

I think the correct part number for 70 hood hinge springs is 546325. 69-70 546325 have 29 coils, 1 7/16 (1.34" - 1.43") outside diameter, 1/4 inch rod size, and measure 9 1/2 inches.

I compared these measurements to a couple sets of 70 only hinge springs and they were the same.

Ames sells a set that is very close in measure with 30 coils (If I'm counting them correctly).

I think 3848272 is 1967-1969 camaro hinges 28 Coils 9 3/8" long.

Matt M. has looked at several original 70 cars including a June built Esprit that is untouched. They had the small diameter springs. I am just curious if they switched late in the model year to the larger spring which is what was used on all 71+ cars.
As said I have a set of 70 only springs here that have the large springs. Hard to believe they were changed but it could be possible.
Also as far as the part number 546325. i do not recognize that number.
The ones referenced in the original post are both available in Repro and NOS on ebay.
Still curious if ALL the EARLY production Firebirds had the little welded tab that is a 1970 only thing.

Are your hinges 524/525?

There is a thread here somewhere on the hinges (and springs I think).
All the ones I have had/seen had the welded piece on the hinges.


:)

My original hinges on my car are blank.and xxxxxxxxx. Not sure why but they are correct

FWIW- My 70 TA has the 524/525 hinges with the small springs and my early 71 TA has the 524/525 hinges with the large springs.

I think some of the confusion came from the engineers on this.
1. The 2nd gen hood Does weigh more than a first ( apples to apples flat hoods)
2. The COMMON theme on replacement "glass' hoods in the 70's and 70's was a "lighter spring"
due to the so called lighter weight of the hood. Due to its distance from the fulcrum and its supports up front
the formula hood weighs as much, or more than a stock flat hood.
Obvioulsy after adding braces, even more.
1970s I have parted had the larger springs, 2 formulas and 2 base 350 and 1 esprit 400. All these cars were post March.
I do know of a stock original Dec car and it has the small springs and metal tail panel. This is a 6 cylinder car with 3 on the tree.

1970 hood hinges have one-year welded support tab & light blue metallic paint stripe/light blue smear

Commonly the left hinge is stamped 525 and right is stamped 524.

Some didn't have the 524/525 stamping. Some had XXXXXXX stamping instead. There's no rhyme or reason for the variations that anyone can figure out.

Adding pictures of the hinges for the thread

So I have the "Survivor" New Orleans Sold 70 Trans Am. Early build date of 01C.
I went a looked at it yesterday
It has original hinges which are PRIOR to the welded tab being added and it DOES have the small springs. Forgot to look for part #.
Funny thing is that these hinges must have failed / loosened so long ago that it actually broke the spot welds loose on the front lip of the hood.
There was a lot going on with the length AND the weight of that hood.
I have several other HINGES at most I have had have the XXXXXXX instead of part number. Is it possible all the LATE cars had the XXXXXX as opposed to part number?
I am building a RAIV car as well which is obviously a LATE car. I am just trying to make sure i put the right spring on there.
Matt has a June Built 70 Esprit...small springs.
Whats throwing me is the set i have that are off the car that have the LARGE springs. that set has all XXXXXX.
All this input is appreciated.

R 70 Judge
On those photos you posted (which are great by the way) am I seeing things or are those the LARGE springs on there?
The small springs would have 28 coils and the LARGE ones have 25 coils.
They look large in the photo and I seem to count 25 coils on there. They sure look like the LARGE ones.
Any idea what those originally came off of?
RA

I didn't know the very early hinges didn't have the weld. Do these hinges look just like the welded hinges except no weld? My buddy has an early 01C build TA. His hinges don't have the weld, but we just assumed they weren't original. We need some pictures of these early hinges. Good stuff.

these last couple posts are making me look at my hinges;
I have a couple extra sets from a gen who parted out some early second gen Firebirds decades ago...

I have pics but it would be better if i visit the car again this weekend and get some good detailed ones. My feeling is that they are original. The car is pretty much untouched. My thought is they failed on the earliest cars such as the 01C built cars as we are noting here and then the "repair" was made quickly in production and then 71 came with the newer hinges. Think the rear arm was changed. I think your buddys 01C is probably the same as mine. Are his SMALL Spring like mine? That would be pretty definitive as ALL 71 up hinges had the larger spring.
Looking at the pics R 70 Judge posted of very original looking 70 hinges with the xxxxxx appears to have large 25 coil springs in stating to make me think it may be possible that they went with the larger spring later in 70 prior to the newly designed 71 spring.
Waiting to have R 70 Judge chime in if he knows what those came off of.

I look forward to any information you might be able to share;
This is new to me.

Just curious whether the hinges on that car were originally phosphate plated, or painted black?

Sorry, I wish I could be more help. They were already removed from the car. I don’t know what they came off of. Not sure on the springs either.

Phosphate.

I had someone point out that the 1970 Camaro may have used the LARGER 25 coil Hinge Spring.
I guess a question is if the 1970 Camaro also used the Welded Tab Hinge as the firebirds did.
I may have to start a new thread "1970 Camaro Hood Hinges" to get some attention there.

you may want to start that discussion on ‘NastyZ28’