67 - Rear coil spring question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**oldman3** · 05-09-2011, 01:38 PM

I redid a friends 67 pickup a couple years ago. We installed a drop kit from CPP. We did a 5" coil spring drop in the rear, with relocators for shocks, c-notch, etc. The pickup is a 67 longbed stepside. It was orginally a 1/2 ton heavy duty long bed. We kept the long bed and added a gas tank at rear of frame. What is happening now is when you ran down the freeway at about 70 mph, the rear axle bounces like a rubber ball. It's not real bad, but you can see it if you watch from another vehicle. I'v talked with CPP and they think I should go to the 4" heavy duty drop coil spring. I think this may take care of the problem, but wanted to check with people on here who may have had this problem, or can help out, before we order the new springs. I have attached several pics, showing old springs & new, and the current underside of pickup. Let me know what you think.

Pic 1 old and new springs
Pic 2-5 shots of undercarriage

fastwillie 696969 · 05-09-2011, 01:41 PM

do you know the spring rating ?

**oldman3** · 05-09-2011, 01:42 PM

Pic 1 more undercarriage.

Pic 2 How tire looks in the opening, tire is a 255/60/17 on Coy rims

Pic 3 & 4 Before and after shot.

**oldman3** · 05-09-2011, 01:48 PM

Quote:

Originally Posted by fastwillie 696969

do you know the spring rating ?

No I'm sorry I don't, they are what CPP sold, part # was 603-5.

Richard H. · 05-09-2011, 01:49 PM

My first thought would be gas adjust shocks or coil overs. Thats some slick detail right there...very nice.

**oldman3** · 05-09-2011, 01:51 PM

Quote:

Originally Posted by Richard H.

My first thought would be gas adjust shocks or coil overs. Thats some slick detail right there...very nice.

I had thought about coil overs also, but cost is the problem. Thanks for the kind words, appreicate it.

Jessechop · 05-09-2011, 02:14 PM

Just a stupid thought, but are the shocks just plain old worn out?

DesertCat · 05-09-2011, 02:20 PM

Sounds to me like there isn't enough dampening with the shocks, maybe they are too weak or worn out. Has this always happened?

Out of balance or out of round tires could be a cause... I chased a problem like this once and after checking everything (and I mean everything) 2-3 times, replaced the 6 month old tires... solved. So just because they look nice and new doesn't necessarily mean they aren't a problem.

Your mileage may vary...

**oldman3** · 05-09-2011, 02:30 PM

Quote:

Originally Posted by Jessechop

Just a stupid thought, but are the shocks just plain old worn out?

Shocks are brand new Doetsch, with less that 1500 miles.

**oldman3** · 05-09-2011, 02:36 PM

Quote:

Originally Posted by DesertCat

Sounds to me like there isn't enough dampening with the shocks, maybe they are too weak or worn out. Has this always happened?

Out of balance or out of round tires could be a cause... I chased a problem like this once and after checking everything (and I mean everything) 2-3 times, replaced the 6 month old tires... solved. So just because they look nice and new doesn't necessarily mean they aren't a problem.

Your mileage may vary...

My thoughts with the dampening also, just not sure, they are new and a brand name (doetsch). I though if the springs were not stiff enough, that the shocks couldn't control the bounce, don't know. Never thought about the tires, will have to talk this over with the owner. Thanks, Jim

05-09-2011, 01:38 PM	#1
oldman3 Senior Member Join Date: Mar 2011 Location: West Plains, Missouri Posts: 7,555	67 - Rear coil spring question I redid a friends 67 pickup a couple years ago. We installed a drop kit from CPP. We did a 5" coil spring drop in the rear, with relocators for shocks, c-notch, etc. The pickup is a 67 longbed stepside. It was orginally a 1/2 ton heavy duty long bed. We kept the long bed and added a gas tank at rear of frame. What is happening now is when you ran down the freeway at about 70 mph, the rear axle bounces like a rubber ball. It's not real bad, but you can see it if you watch from another vehicle. I'v talked with CPP and they think I should go to the 4" heavy duty drop coil spring. I think this may take care of the problem, but wanted to check with people on here who may have had this problem, or can help out, before we order the new springs. I have attached several pics, showing old springs & new, and the current underside of pickup. Let me know what you think. Pic 1 old and new springs Pic 2-5 shots of undercarriage Attached Images __________________ my build thread: http://67-72chevytrucks.com/vboard/s...d.php?t=459839 Jimbo's long bed step build:http://67-72chevytrucks.com/vboard/s...t=464626<br /> Last edited by oldman3; 05-09-2011 at 01:46 PM.

05-09-2011, 01:41 PM	#2
fastwillie 696969 ~Rest In Peace~ Join Date: May 2005 Location: CALIFORNIA NOR CAL Posts: 9,707	Re: 67 - Rear coil spring question do you know the spring rating ? __________________ is it fast ? it has a lighting bolt donut? B___H please, I can remove 90% of your so called "beauty" with a kleenex

05-09-2011, 01:42 PM	#3
oldman3 Senior Member Join Date: Mar 2011 Location: West Plains, Missouri Posts: 7,555	Re: 67 - Rear coil spring question Pic 1 more undercarriage. Pic 2 How tire looks in the opening, tire is a 255/60/17 on Coy rims Pic 3 & 4 Before and after shot. Attached Images __________________ my build thread: http://67-72chevytrucks.com/vboard/s...d.php?t=459839 Jimbo's long bed step build:http://67-72chevytrucks.com/vboard/s...t=464626<br />

05-09-2011, 01:49 PM	#5
Richard H. Spanked once Join Date: Oct 2006 Location: Intheshop, Indiana Posts: 969	Re: 67 - Rear coil spring question My first thought would be gas adjust shocks or coil overs. Thats some slick detail right there...very nice. __________________ The ole 350 budget build.

05-09-2011, 02:14 PM	#7
Jessechop Registered User Join Date: Sep 2003 Location: maine Posts: 191	Re: 67 - Rear coil spring question Just a stupid thought, but are the shocks just plain old worn out?

05-09-2011, 02:20 PM	#8
DesertCat Registered User Join Date: Mar 2011 Location: Valley of the Sunstroke, Arizona Posts: 1,210	Re: 67 - Rear coil spring question Sounds to me like there isn't enough dampening with the shocks, maybe they are too weak or worn out. Has this always happened? Out of balance or out of round tires could be a cause... I chased a problem like this once and after checking everything (and I mean everything) 2-3 times, replaced the 6 month old tires... solved. So just because they look nice and new doesn't necessarily mean they aren't a problem. Your mileage may vary... __________________ My build thread - Devastation and Reform http://67-72chevytrucks.com/vboard/s...d.php?t=567131



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