Author Topic: 69 Z28 Leaf Springs. (Read 9352 times)

onekidbill · « **on:** February 13, 2019, 11:53:57 PM »

Hi ,
First time on the Forum,
I have a 69 Z28 that I've owned since 1976 and I'm in the process of putting the motor and a few other stock items back in the car. I'm from BC Canada and have GM of Canada Doc. on the car so I know its a true Z.My question is that will reading on the CRG site I came onto an article about the rear Leaf springs that there should be 4 and my car has 5. Can someone tell me if this possible as I know the rear end was changed but the springs came stock on this car.

Bill

BillG · « **Reply #1 on:** February 14, 2019, 12:00:03 AM »

4 leaf springs were part of the z28 option as you probably know. Mabey when the rear was changed, the springs were changed along with it?

onekidbill · « **Reply #2 on:** February 14, 2019, 12:05:08 AM »

Thanks Bill
I have a orignal 68 z28 and it only has 4 so maybe it was changed.

bertfam · « **Reply #3 on:** February 14, 2019, 01:06:21 AM »

Don't toss them too quickly! From the 1969 CAMARO VISUAL ID HYPERTABLE (Note 10):

Quote

Generally, Z28's used 4-leaf springs and the other multi-leaf spring applications used 5-leaf springs. However, the use of 4-leaf springs was not limited to just 68-69 Z28's. Spring selection was a function of weight and options - and this was fine-tuned in 1969. SS, LM1, L65, and COPO cars with 4-leaf springs are possible according to factory documentation and they have been observed on original SS, LM1, and L65 cars.
Factory documentation indicates that all 68-69 Z28's should have 4-leaf springs. One Z28 (a 69) has been found with apparently original 5-leaf springs. The 5-leaf spring usage on a Z28 should not be considered normative and CRG continues research whether 5-leaf springs were factory installed on the Z28.

Since that was written, we now have 6 1969 Z28's in the database with 5 leaf springs. Again, this isn't "normal", and we continue to research this, but we would LOVE to have data on your car.

You stated that the rear axle's been changed. What's the code stamped on the passenger side axle tube? This "might" help to confirm if the springs originally came on that particular axle.

Ed

x77-69z28 · « **Reply #4 on:** February 14, 2019, 03:16:42 AM »

My car had a helper spring installed at some point prior to me purchasing the car in 1978, with 32,000 miles on it.

jdv69z · « **Reply #5 on:** February 14, 2019, 08:14:15 PM »

So when counting the number springs, do you count the lowest one which sits directly on the spring perch? It is much shorter than the others. Is that a spring, or just for mounting?

bertfam · « **Reply #6 on:** February 14, 2019, 08:30:40 PM »

Quote

So when counting the number springs, do you count the lowest one which sits directly on the spring perch? It is much shorter than the others. Is that a spring, or just for mounting?

See attached.

Ed

onekidbill · « **Reply #7 on:** February 14, 2019, 11:34:28 PM »

Hi Ed
Here are some pics

onekidbill · « **Reply #8 on:** February 14, 2019, 11:36:09 PM »

bertfam · « **Reply #9 on:** February 15, 2019, 12:48:45 AM »

Hard to tell from the pictures (too small), it appears those "might" be originals. Can you post a higher resolution shot of the clamps and the ends of one of the leafs?

Ed

bcmiller · « **Reply #10 on:** February 15, 2019, 01:35:22 PM »

Bill was the whole rear end housing swapped out? What gear is in it now?

jdv69z · « **Reply #11 on:** February 15, 2019, 01:59:51 PM »

Thanks Ed, couldn't be much clearer than those pics. So my 69 Z has 5 springs, but it doesn't mean anything because I have a receipt from a previous owner showing that they were replaced. I'm guessing they were changed from 4 to 5 leafs at that point? Although the stance of my car seems to look to be the same as other Z's. Could be that the 5 leaf springs had the same effective spring rate as the original 4 leaf I guess.

Mike S · « **Reply #12 on:** February 15, 2019, 05:21:45 PM »

With the factory multi-leafs.....was the main spring a dual taper (width and thickness) like the mono leaf, or was it a continuous width along its entire length (I assume the thickness was tapered).
Just curious.

Mike

onekidbill · « **Reply #13 on:** February 15, 2019, 07:06:31 PM »

Hi Ed'
When I restored the car back in 82, I installed a 12 bolt posi with an original set of 3:37 gears out 69 Z. But the springs were never changed.I'll get the numbers off the housing and let you know.

onekidbill · « **Reply #14 on:** February 15, 2019, 07:08:16 PM »

More pice

Mike S · « **Reply #15 on:** February 15, 2019, 07:19:09 PM »

That fact that the spacing between the upper perch and lower perch bracket is not fully closed make me believe a leaf was added. I don't think the factory would leave a spacing like that.

Mike

bertfam · « **Reply #16 on:** February 15, 2019, 07:23:10 PM »

Well, either those springs have been modified/repaired, or they're not original. Every leaf should have the rectangular "pocket" at the end, and tapered (one of them appears to be just cut off). Also, the clamps (also known as straps) don't look original either. I agree, I think someone took an original set of 4 leaf springs and added another (incorrect) leaf!

And I'm assuming you mean a 3.73 gear, not 3.37, right?

Quote

With the factory multi-leafs.....was the main spring a dual taper (width and thickness) like the mono leaf, or was it a continuous width along its entire length

Mike, the only taper is at the end of each leaf. Approx the last 2 to 2.5" inches. The rest is all one thickness and width.

Ed

onekidbill · « **Reply #17 on:** February 15, 2019, 07:42:11 PM »

Hi Ed
Sorry that was 3:73 gears I installed. The rear end looks like it was a 68 or 69 BS 3;31 12 bolt posi.

cook_dw · « **Reply #18 on:** February 15, 2019, 07:47:47 PM »

Someone did the same thing to my 68 BITD. 4 leaf with the 5 added. I was told it was an old drag racer trick. Not sure how legit that really is.

69Z28-RS · « **Reply #19 on:** February 15, 2019, 08:07:45 PM »

Quote from: cook_dw on February 15, 2019, 07:47:47 PM

Someone did the same thing to my 68 BITD. 4 leaf with the 5 added. I was told it was an old drag racer trick. Not sure how legit that really is.

...you're not sure how 'legit' it is ...from what perspective???

bertfam · « **Reply #20 on:** February 15, 2019, 08:12:06 PM »

Quote

The rear end looks like it was a 68 or 69 BS 3;31 12 bolt posi

It's a 3.31 12 bolt posi alright, but it originally came out of a 1971 Nova! That axle was assembled at the Warren, MI plant on the night shift, Julian day 062 (?) which would have been Wednesday, March 3rd, 1971.

Ed

cook_dw · « **Reply #21 on:** February 15, 2019, 09:03:00 PM »

Quote from: 69Z28-RS on February 15, 2019, 08:07:45 PM

Quote from: cook_dw on February 15, 2019, 07:47:47 PM
Someone did the same thing to my 68 BITD. 4 leaf with the 5 added. I was told it was an old drag racer trick. Not sure how legit that really is.

...you're not sure how 'legit' it is ...from what perspective???

The racing theory.

onekidbill · « **Reply #22 on:** February 15, 2019, 09:12:41 PM »

Thanks Guys. It will be nice to get it back on the road this regardless.

69Z28-RS · « **Reply #23 on:** February 15, 2019, 10:25:57 PM »

Quote from: cook_dw on February 15, 2019, 09:03:00 PM

Quote from: 69Z28-RS on February 15, 2019, 08:07:45 PM
Quote from: cook_dw on February 15, 2019, 07:47:47 PM
Someone did the same thing to my 68 BITD. 4 leaf with the 5 added. I was told it was an old drag racer trick. Not sure how legit that really is.

It should stiffen the rear suspension up a bit... but your traction bars might do as well or better at putting the power to the pavement?

...you're not sure how 'legit' it is ...from what perspective???

The racing theory.

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Author Topic: 69 Z28 Leaf Springs. (Read 9352 times)