Rear Coil Spring - The 1947 - Present Chevrolet & GMC Truck Message Board Network

MStokes · 01-02-2003, 10:39 AM

This is a photo of my rear coil spring. When I got to looking at it I noticed that the wraps in the coils are closer together in the center of the spring. The other side is the same way.

Is this normal for a stock spring, or was is lowered at some point by heating it?

**1971Stepside** · 01-02-2003, 10:46 AM

Looks like it was heated to me. My stock coils did not look like that.

MStokes · 01-02-2003, 10:49 AM

Is there a way to measure the stance of the truck like dimensions from the ground to the high point on the fender above the wheel?

This truck is a 72 C10.

jmil1974 · 01-02-2003, 11:21 AM

I would have to guess lowered too. My springs don't look like that either.

**1971Stepside** · 01-02-2003, 11:24 AM

MStokes, this would be possible I just can't help you since my truck is just a frame right now. I'm sure someone on here can post stock height measurements for you. Do you want it stock or lowered?

MStokes · 01-02-2003, 11:28 AM

I'd like to find out what stock is so that I can compare it to what my truck currently sits at. I think I want to go with a 2.5/4 drop on it but want to make sure I don't mess up the driveability of it with wheel clearances and handling.

It would help to know if any of the previous owners did anything to change the stock height of the truck.

**JQ-72** · 01-02-2003, 11:28 AM

Your springs are what Chevrolet advertised as two-stage design on all 10 and 20 series. Here is a quote taken from a '65 dealer brochure :

"Coil-spring rear suspension for series 10 and 20 gives superior ride and load control because of its special two-stage design. A single set of springs gives softness for smooth ride when lightly loaded, plus firm control for top payloads and extra duribility. Two stage action is accomplished by reducing the number of active spring coils as load is increased. Closely spaced central coils (see left) close and become inactive under moderate loads, giving extra spring stiffness and firm load support."

It shows a picture of the coil spring with the closely spaced central coils. Hope this helps!

Joshua

MStokes · 01-02-2003, 11:31 AM

That helps a bunch. Does it say if all 72's with coil rear ends came with these springs, or was it some kind of option?

**JQ-72** · 01-02-2003, 11:39 AM

These two stage springs were used from the early 60's until 72. I just double checked a 72 brochure and it mentions two-stage design also. This was not an option. All coil rear trucks had them.

Joshua

jmil1974 · 01-02-2003, 11:46 AM

Wow, I guess when my uncle said he changed to C20 rear coils -- he meant it.

**1971Stepside** · 01-02-2003, 11:55 AM

Mine was a c10 with original springs and it did not have them....hmmmmm

slam33 · 01-02-2003, 11:56 AM

My 3/4's are like that

crazy longhorn · 01-02-2003, 12:00 PM

the coil trucks that I have had were wrapped tighter in the center.......I wouldnt doubt that your springs are sagged from 30+ yrs of use tho.....

cnshoot · 01-02-2003, 12:05 PM

there are diff springs for diff apllications some have them some dont but they are stock with the heated center. it was for the ride of the truck. one side of the spring would take the weight and the other would take the ride so thus a load and smooth ride

Longhorn Man · 01-03-2003, 12:35 AM

I have never seen a rear coil that was not like that.

**1971Stepside** · 01-03-2003, 12:49 AM

I would love to show you mine, but they are now in the local landfill. Hmmm, let me dig around...I may have a pic of them during the disassembly. I may be wrong, but I sure don't remember them looking like that.

**1971Stepside** · 01-03-2003, 12:55 AM

I think I stand corrected, but this is a bad pic to tell from. It looks like the right one is that way but the left one is different. Who knows and you guys are the experts...

orange72 · 01-03-2003, 03:20 AM

ive never seen a stock coil like that either...those center coils are usually close together but not that close. on my truck the previous owner lowered it by heating them up and it sure rides rough. my springs also look something like that too. but i may be wrong. ill go look at one of the trucks in the field to see tomorow.

Hotrod70C10 · 01-03-2003, 03:41 AM

The coils in my 70 were like that also. Mine weren't heated up they were just pure junk after 30 plus years of abuse. My uncle had my truck for the past 12 years drove it everyday and towed all kinds of heavy equipment with it. Oh...My truck also shows an option for HD rear coils. I went with a 2/4 drop with mine it rides like a new truck compared to how it used to with those old coils bottoming out all the time!

TERRYP · 01-03-2003, 04:10 AM

All panel trucks of that era had non-progressive rear springs, these were the only model that way. I do not know why. ECE springs are straight wound, also.

da-burb · 01-03-2003, 10:50 AM

Mine are just like the ones in your picture. They are just a few years old and were called "variable rate springs" in the catalog.

ChevLoRay · 01-03-2003, 11:11 AM

During the time I was laid off from my "good" job in the mid-70's, I was forced to find other work....which I found at "the world's largest department store auto center".

I changed enough shocks to have seen both types of springs that you have all mentioned. I recall seeing those springs on the 3/4-tonners. Half-tons could have either. My '69 had extra capacity springs. i.e., 2000-lb option, and had them, too. This is on a short wheel base truck. So, you KNOW I had a rough ride until I changed them and lowered it. Still got the hitch, tho.

BobM · 01-03-2003, 04:45 PM

The originals in mine were of the same design. Put in in a new set which are called "variable ride". The coils are closer at one end than at the other end. Only question I had about them is "what is the proper way to put them in?" Do the closer wound coils go at the top or bottom? Haven't found anyone that can give me a definitive answer. Any of you guys want to give it a shot???

**1971Stepside** · 01-03-2003, 05:18 PM

BobM, if you look at the picture of my frame (when it was ugly) up above you can see the passenger side spring seems to have the tighter wound coils at the top. I don't know if that helps or not. You might be able to tell by the way the retainer cups fit?????

greasemonkey · 01-03-2003, 07:19 PM

Mine look like that.

01-02-2003, 10:39 AM	#1
MStokes Registered User Join Date: Aug 2002 Location: Meridian, Idaho Posts: 164	Rear Coil Spring This is a photo of my rear coil spring. When I got to looking at it I noticed that the wraps in the coils are closer together in the center of the spring. The other side is the same way. Is this normal for a stock spring, or was is lowered at some point by heating it? Attached Images __________________ 1972 C-10 LWB, 400/350, 2WD 1972 C-20 Custom Camper, 350/350, 4WD (Converted)

01-02-2003, 10:46 AM	#2
1971Stepside Almost Satisfied Join Date: Mar 2002 Location: Springfield, MO Posts: 2,932	Looks like it was heated to me. My stock coils did not look like that. __________________ 1971 C10 Stepside. LSx 6.0 with BTR Stage IV, Speed Engineering Headers, 4L80e transmission w/3200 Circle-D Stall. 3.73. Posi. Purchased this truck when I was 17. I started the rebuild (or take apart) in 1993. I have drug it around all over the country in pieces. Finally back on the road in 2021. "I can't complain, but sometimes I still do. Life's been good to me so far."

01-02-2003, 10:49 AM	#3
MStokes Registered User Join Date: Aug 2002 Location: Meridian, Idaho Posts: 164	Is there a way to measure the stance of the truck like dimensions from the ground to the high point on the fender above the wheel? This truck is a 72 C10. __________________ 1972 C-10 LWB, 400/350, 2WD 1972 C-20 Custom Camper, 350/350, 4WD (Converted)

01-02-2003, 11:21 AM	#4
jmil1974 Ain't we cute? Join Date: May 2002 Location: Friendswood, TX Posts: 700	I would have to guess lowered too. My springs don't look like that either. __________________ 69 C10 2WD LWB Fleet 350/350 power front disc conversion (6 lug disc kit from gmcpauls) and new engine, PS, A/C, fresh fluids, SHE DRIVES! FOR SALE $3900

01-02-2003, 11:24 AM	#5
1971Stepside Almost Satisfied Join Date: Mar 2002 Location: Springfield, MO Posts: 2,932	MStokes, this would be possible I just can't help you since my truck is just a frame right now. I'm sure someone on here can post stock height measurements for you. Do you want it stock or lowered? __________________ 1971 C10 Stepside. LSx 6.0 with BTR Stage IV, Speed Engineering Headers, 4L80e transmission w/3200 Circle-D Stall. 3.73. Posi. Purchased this truck when I was 17. I started the rebuild (or take apart) in 1993. I have drug it around all over the country in pieces. Finally back on the road in 2021. "I can't complain, but sometimes I still do. Life's been good to me so far."

01-02-2003, 11:28 AM	#6
MStokes Registered User Join Date: Aug 2002 Location: Meridian, Idaho Posts: 164	I'd like to find out what stock is so that I can compare it to what my truck currently sits at. I think I want to go with a 2.5/4 drop on it but want to make sure I don't mess up the driveability of it with wheel clearances and handling. It would help to know if any of the previous owners did anything to change the stock height of the truck. __________________ 1972 C-10 LWB, 400/350, 2WD 1972 C-20 Custom Camper, 350/350, 4WD (Converted)

01-02-2003, 11:28 AM	#7
JQ-72 Senior Member Join Date: Feb 2001 Location: Killen, Alabama USA Posts: 3,615	Your springs are what Chevrolet advertised as two-stage design on all 10 and 20 series. Here is a quote taken from a '65 dealer brochure : "Coil-spring rear suspension for series 10 and 20 gives superior ride and load control because of its special two-stage design. A single set of springs gives softness for smooth ride when lightly loaded, plus firm control for top payloads and extra duribility. Two stage action is accomplished by reducing the number of active spring coils as load is increased. Closely spaced central coils (see left) close and become inactive under moderate loads, giving extra spring stiffness and firm load support." It shows a picture of the coil spring with the closely spaced central coils. Hope this helps! Joshua __________________ 72 Cheyenne Super swb. Factory 402/400,tach,posi,AM/FM, A/C. Adding cruise, 8-track 72 Cheyenne Super swb. 350/350 A/C, bucket seats 72 Cheyenne swb. Factory 402/400, tilt, posi, A/C 72 Cheyenne Super K-10. 350/4 spd., posi. 72 Suburban 350/350 tilt, tach, AM/FM, A/C, luggage rack 72 GMC Sierra lwb. 350/350, A/C. medium green/olive interior

01-02-2003, 11:31 AM	#8
MStokes Registered User Join Date: Aug 2002 Location: Meridian, Idaho Posts: 164	That helps a bunch. Does it say if all 72's with coil rear ends came with these springs, or was it some kind of option? __________________ 1972 C-10 LWB, 400/350, 2WD 1972 C-20 Custom Camper, 350/350, 4WD (Converted)

01-02-2003, 11:39 AM	#9
JQ-72 Senior Member Join Date: Feb 2001 Location: Killen, Alabama USA Posts: 3,615	These two stage springs were used from the early 60's until 72. I just double checked a 72 brochure and it mentions two-stage design also. This was not an option. All coil rear trucks had them. Joshua __________________ 72 Cheyenne Super swb. Factory 402/400,tach,posi,AM/FM, A/C. Adding cruise, 8-track 72 Cheyenne Super swb. 350/350 A/C, bucket seats 72 Cheyenne swb. Factory 402/400, tilt, posi, A/C 72 Cheyenne Super K-10. 350/4 spd., posi. 72 Suburban 350/350 tilt, tach, AM/FM, A/C, luggage rack 72 GMC Sierra lwb. 350/350, A/C. medium green/olive interior

01-02-2003, 11:46 AM	#10
jmil1974 Ain't we cute? Join Date: May 2002 Location: Friendswood, TX Posts: 700	Wow, I guess when my uncle said he changed to C20 rear coils -- he meant it. __________________ 69 C10 2WD LWB Fleet 350/350 power front disc conversion (6 lug disc kit from gmcpauls) and new engine, PS, A/C, fresh fluids, SHE DRIVES! FOR SALE $3900

01-02-2003, 11:55 AM	#11
1971Stepside Almost Satisfied Join Date: Mar 2002 Location: Springfield, MO Posts: 2,932	Mine was a c10 with original springs and it did not have them....hmmmmm __________________ 1971 C10 Stepside. LSx 6.0 with BTR Stage IV, Speed Engineering Headers, 4L80e transmission w/3200 Circle-D Stall. 3.73. Posi. Purchased this truck when I was 17. I started the rebuild (or take apart) in 1993. I have drug it around all over the country in pieces. Finally back on the road in 2021. "I can't complain, but sometimes I still do. Life's been good to me so far."

01-02-2003, 11:56 AM	#12
slam33 Registered User Join Date: Aug 2001 Location: Long Beach, Ca Posts: 1,432	My 3/4's are like that __________________ 71 LWB 350/350still working on it but it's going tp be sweet. www.geocities.com/stevemau/slam33page.html " TARGET=_blank>http://www.geocities.com/stevemau/slam33page.html?1004806705410 </A>

01-02-2003, 12:00 PM	#13
crazy longhorn Fabricate till you "puke" Join Date: Jun 2002 Location: Ill Posts: 9,402	the coil trucks that I have had were wrapped tighter in the center.......I wouldnt doubt that your springs are sagged from 30+ yrs of use tho..... __________________ 69 longhorn,4" chop,3/5 drop, 1/2 ton suspension/disc brakes,1 1/2" body drop,steel tilt clip, 5.3/Edelbrock rpm intake/600 carb, Hooker streetrod shorties,2 1/2" exhaust/ H pipe/50's Flows , 6 spd Richmond trans,12 bolt/ 3.40 gears....

01-02-2003, 12:05 PM	#14
cnshoot Registered User Join Date: Jan 2003 Location: minden Posts: 358	there are diff springs for diff apllications some have them some dont but they are stock with the heated center. it was for the ride of the truck. one side of the spring would take the weight and the other would take the ride so thus a load and smooth ride

01-03-2003, 12:35 AM	#15
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	I have never seen a rear coil that was not like that.



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01-03-2003, 12:49 AM	#16
1971Stepside Almost Satisfied Join Date: Mar 2002 Location: Springfield, MO Posts: 2,932	I would love to show you mine, but they are now in the local landfill. Hmmm, let me dig around...I may have a pic of them during the disassembly. I may be wrong, but I sure don't remember them looking like that. __________________ 1971 C10 Stepside. LSx 6.0 with BTR Stage IV, Speed Engineering Headers, 4L80e transmission w/3200 Circle-D Stall. 3.73. Posi. Purchased this truck when I was 17. I started the rebuild (or take apart) in 1993. I have drug it around all over the country in pieces. Finally back on the road in 2021. "I can't complain, but sometimes I still do. Life's been good to me so far."

01-03-2003, 12:55 AM	#17
1971Stepside Almost Satisfied Join Date: Mar 2002 Location: Springfield, MO Posts: 2,932	Hmmmm I think I stand corrected, but this is a bad pic to tell from. It looks like the right one is that way but the left one is different. Who knows and you guys are the experts... Attached Images __________________ 1971 C10 Stepside. LSx 6.0 with BTR Stage IV, Speed Engineering Headers, 4L80e transmission w/3200 Circle-D Stall. 3.73. Posi. Purchased this truck when I was 17. I started the rebuild (or take apart) in 1993. I have drug it around all over the country in pieces. Finally back on the road in 2021. "I can't complain, but sometimes I still do. Life's been good to me so far."

01-03-2003, 03:20 AM	#18
orange72 Registered User Join Date: Sep 2000 Location: huntington,texas,united states Posts: 399	ive never seen a stock coil like that either...those center coils are usually close together but not that close. on my truck the previous owner lowered it by heating them up and it sure rides rough. my springs also look something like that too. but i may be wrong. ill go look at one of the trucks in the field to see tomorow. __________________ 1972 chevy long bed. Currently under construction!! Bagged, 383/700r4.

01-03-2003, 03:41 AM	#19
Hotrod70C10 Low & Slow Join Date: Dec 2002 Location: Oklahoma Posts: 1,047	The coils in my 70 were like that also. Mine weren't heated up they were just pure junk after 30 plus years of abuse. My uncle had my truck for the past 12 years drove it everyday and towed all kinds of heavy equipment with it. Oh...My truck also shows an option for HD rear coils. I went with a 2/4 drop with mine it rides like a new truck compared to how it used to with those old coils bottoming out all the time!

01-03-2003, 04:10 AM	#20
TERRYP GYRO GEARLOOSE Join Date: Jun 2000 Location: Nevada City, CAEverett, WA Posts: 361	All panel trucks of that era had non-progressive rear springs, these were the only model that way. I do not know why. ECE springs are straight wound, also. __________________ Nevada City, CA Everett, Washington 57 3/4 rat, 235, 3spd 66 C-10 Panel, SWB. 350 from '68, 200R4 tranny, 3.07 rear ratio, restoring 68 C10 LWB 350 4spd, 4.56 rear dump runner 82 Camaro, 305, THM-200-R4 84 Monte Carlo 305 TH350, land tuna 85 Tercel SW, snow runner DISGRACED OUTLAW MEMBER OF THE DRUM BRAKE CLUB

01-03-2003, 10:50 AM	#21
da-burb "Ochre Ogre" Join Date: Apr 2000 Location: Springfield, MN Posts: 3,558	Mine are just like the ones in your picture. They are just a few years old and were called "variable rate springs" in the catalog. __________________ Bowtie Truck Stop Inc. Mid-West GM Truck Restoration Parts Supplier Your Key Parts, Auto Metal Direct, Dynacorn, and Goodmark dealer. like us @ www.facebook.com/BowtieTruckStop 1971 C-10 Suburban (Ochre) 1971 K-10 Suburban (Ochre) 1972 C-10 Suburban (Ochre) 1972 K-20 Suburban (Yellow- that just aint right!) Springfield, Minnesota 56087

01-03-2003, 11:11 AM	#22
ChevLoRay Old Skool Club Join Date: Jun 2001 Location: Benton, AR "The Heart of Arkansas" Posts: 10,880	During the time I was laid off from my "good" job in the mid-70's, I was forced to find other work....which I found at "the world's largest department store auto center". I changed enough shocks to have seen both types of springs that you have all mentioned. I recall seeing those springs on the 3/4-tonners. Half-tons could have either. My '69 had extra capacity springs. i.e., 2000-lb option, and had them, too. This is on a short wheel base truck. So, you KNOW I had a rough ride until I changed them and lowered it. Still got the hitch, tho. __________________ Member Nr. 2770 '96 GMC Sportside; 4.3/SLT - Daily driven....constantly needs washed. '69 C-10 SWB; 350/TH400 - in limbo The older I get, the better I was.

01-03-2003, 04:45 PM	#23
BobM Registered User Join Date: Feb 2001 Location: Winnipeg, MB, Canada Posts: 73	The originals in mine were of the same design. Put in in a new set which are called "variable ride". The coils are closer at one end than at the other end. Only question I had about them is "what is the proper way to put them in?" Do the closer wound coils go at the top or bottom? Haven't found anyone that can give me a definitive answer. Any of you guys want to give it a shot???

01-03-2003, 05:18 PM	#24
1971Stepside Almost Satisfied Join Date: Mar 2002 Location: Springfield, MO Posts: 2,932	BobM, if you look at the picture of my frame (when it was ugly) up above you can see the passenger side spring seems to have the tighter wound coils at the top. I don't know if that helps or not. You might be able to tell by the way the retainer cups fit????? __________________ 1971 C10 Stepside. LSx 6.0 with BTR Stage IV, Speed Engineering Headers, 4L80e transmission w/3200 Circle-D Stall. 3.73. Posi. Purchased this truck when I was 17. I started the rebuild (or take apart) in 1993. I have drug it around all over the country in pieces. Finally back on the road in 2021. "I can't complain, but sometimes I still do. Life's been good to me so far."

01-03-2003, 07:19 PM	#25
greasemonkey Registered User Join Date: Dec 2001 Location: Pace, FL Posts: 2,155	Mine look like that. __________________ 1942 Master Deluxe 1969 C/10 1985 Blazer CUCV 1987 Jimmy 2004 Tahoe 2005 Silverado 1500 2005 Silverado 3500

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