C20 Leaf Springs or Coils

[Joe Cool]

Was the leaf spring an option on the C20?

I found a long bed C20 that I want to use for camping but it has coils instead of leaf...........which because I am ignorant....I was not familiar with.

Anybody know the spring rate of the C20 Coil pack?

I am just curious if it would work with a truck camper....?

Leaf Spring is a no brainer........not sure on the coil.......

[54blackhornet]

Joe, I have a stock 71 C-20 with coils and factory overload springs, I only use it to bring in green firewood every summer. It will hold about three cords when I use tall side boards. Not sure how much that weighs but more then a truck camper I bet ?

[Jahloha]

1970 C20 with coils on all four corners. Gramps ran a truck camper on this truck for nearly 30 years, no issues. I also have towed 5-6k lb loads without issues.

Also, a cord of wood has got to be pushing at least a ton, right?

Hope this helps.

[Coley]

I think that Chevy standardized on coil spring/trailing arm rear suspension as the factory 'as delivered' default with the leaf springs as an option and I think GMC was the opposite.
If it is a C20- 3/4ton, either one should work ok with a camper BUT......it depends on the camper you are looking at? (ie: 8'? 9'? 10'? or??? and what its weight is).
Do you have any information off of the SPID in the glovebox? (H.duty rear springs? auxiliary overloads? or??? camper special options?).
Also look at the GVWR plate in the door sill.....does it say 7500lbs as manufactured or?
The leaf springs always provided a more stabil load when carrying weight but the coils could carry quite a bit.
The thing with a camper vs other types of loads is the high/sway element where you would notice the advantage of the leaf spring and multi-point load carrying stability.
My two bits.
Coley

[kwmech]

Originally Posted by 54blackhornet

Joe


, I only use it to bring in green firewood every summer. It will hold about three cords when I use tall side boards.

I'll have to call bs on that one.......the wood would have to be stacked 8-9' high and weigh in upwards of 8k. A cord of wet oak can weigh in the neighborhood of 4000#+ by itself. I've got a GMC 3/4 with 10 leafs and I am maxed out at 4200# in the bed ...gravel

[54blackhornet]

May be closer to two cords! And it's pine and red fir, not oak which is a lot heavier when wet !

[FirstOwner69]

Originally Posted by Coley

I think that Chevy standardized on coil spring/trailing arm rear suspension as the factory 'as delivered' default with the leaf springs as an option and I think GMC was the opposite.
If it is a C20- 3/4ton, either one should work ok with a camper BUT......it depends on the camper you are looking at? (ie: 8'? 9'? 10'? or??? and what its weight is).
Do you have any information off of the SPID in the glovebox? (H.duty rear springs? auxiliary overloads? or??? camper special options?).
Also look at the GVWR plate in the door sill.....does it say 7500lbs as manufactured or?
The leaf springs always provided a more stabil load when carrying weight but the coils could carry quite a bit.
The thing with a camper vs other types of loads is the high/sway element where you would notice the advantage of the leaf spring and multi-point load carrying stability.
My two bits.
Coley

I agree 100%, especially regarding the stability and sway aspects of coils. Below is a picture of mine serving camper duty in 1970 (ignore date on picture). I had many white knuckle hours driving that rig. The truck includes the HD rear auxiliary springs with a GVWR of 7500#. I never weighed that 11 foot camper, but always guessed it weighed about 2500-2800 pounds. Eventually, I added air bags, 12.00X16.5 rear tires and a Hellweg rear sway bar. I also made a modification so the auxiliary springs were always in contact with the rubber pads. Those add-ons helped slightly.

[Prematuregrey]

Originally Posted by kwmech

I'll have to call bs on that one.......the wood would have to be stacked 8-9' high and weigh in upwards of 8k. A cord of wet oak can weigh in the neighborhood of 4000#+ by itself. I've got a GMC 3/4 with 10 leafs and I am maxed out at 4200# in the bed ...gravel

I agree, a "cord" is measured as 8' x 4' x 4' ( basically (3) 8' rows stacked 4' high cut 14-16" long when done unloading). Weight not considered, 2 cords would fit if stacked about 6-7' tall in the bed and I feel sorry for the truck at that. When I used haul/sell firewood, I'd show up with a bed load level with the bedsides for a cord and bring a low boy trailer flat loaded about 18" deep if they want 2 cords.

I would like to see a pic of the factory overload helpers with coils. Did they install overload leafs alone or was it a type of coil over or air shock helper spring?

To the OP, I don't think you'll have an issue with a camper on 3/4 ton coil spring setup provided everything is still at spec. After 40+ years coils do degrade a lot in their spring rate so new coils would be advised.

[Joe Cool]

Originally Posted by Prematuregrey

I agree, a "cord" is measured as 8' x 4' x 4' ( basically (3) 8' rows stacked 4' high cut 14-16" long when done unloading). Weight not considered, 2 cords would fit if stacked about 6-7' tall in the bed and I feel sorry for the truck at that. When I used haul/sell firewood, I'd show up with a bed load level with the bedsides for a cord and bring a low boy trailer flat loaded about 18" deep if they want 2 cords.

I would like to see a pic of the factory overload helpers with coils. Did they install overload leafs alone or was it a type of coil over or air shock helper spring?

To the OP, I don't think you'll have an issue with a camper on 3/4 ton coil spring setup provided everything is still at spec. After 40+ years coils do degrade a lot in their spring rate so new coils would be advised.

I am sure the coils need to be replaced and maybe air bags as well.........I am thinking the leaf is a better option for us.......

Truck Campers of the era in the picture probably exceeded 3000 pounds...the new aluminum frames are much lighter............but even then they are heavy

[Joe Cool]

Originally Posted by FirstOwner69

I agree 100%, especially regarding the stability and sway aspects of coils. Below is a picture of mine serving camper duty in 1970 (ignore date on picture). I had many white knuckle hours driving that rig. The truck includes the HD rear auxiliary springs with a GVWR of 7500#. I never weighed that 11 foot camper, but always guessed it weighed about 2500-2800 pounds. Eventually, I added air bags, 12.00X16.5 rear tires and a Hellweg rear sway bar. I also made a modification so the auxiliary springs were always in contact with the rubber pads. Those add-ons helped slightly.

I can tell you that camper weighs at least 3500 pounds.........had a few of them...

[FirstOwner69]

Originally Posted by Joe Cool

I can tell you that camper weighs at least 3500 pounds.........had a few of them...

The camper shown is not self contained so it may be a bit lighter. I ran the truck and loaded camper, with my wife in the cab (about 140# there, so no jokes please) over a scale back then. I believe the total was 7240#. Motorcycle was not on board.

[Joe Cool]

Originally Posted by FirstOwner69

The camper shown is not self contained so it may be a bit lighter. I ran the truck and loaded camper, with my wife in the cab (about 140# there, so no jokes please) over a scale back then. I believe the total was 7240#. Motorcycle was not on board.

Yes It would be lighter for sure...........but you did not like the coil spring?

[FirstOwner69]

Originally Posted by Joe Cool

Yes It would be lighter for sure...........but you did not like the coil spring?

I was never comfortable driving it. I drove the truck with camper onboard probably 25,000 miles, and there was always a sense of not being in control. It always felt like the tail wagging the dog. Many uncomfortable driving moments. The first couple years I had it stored in a lot next to a similar unit mounted on a 3/4 ton Ford (leaf springs, of course). I rocked both units and immediately decided that leaf springs (not Ford) were the way to go due to much less rocking, less rebound and better stability. I later used the camper on a 86 Chevy crew cab dually and it worked great. I now have a 4000#, 11.5' Lance camper on a 06 crew cab Duramax dually and will never use anything else other than a newer version.

Edit: You might consider a shorter (8' or 9' unit and perhaps also one that is narrower. This camper is 11' (floor length) long and 8' wide.

[FirstOwner69]

Originally Posted by Prematuregrey

I would like to see a pic of the factory overload helpers with coils. Did they install overload leafs alone or was it a type of coil over or air shock helper spring?

Here is the best picture I have on file...same truck.

[Joe Cool]

Originally Posted by FirstOwner69

I was never comfortable driving it. I drove the truck with camper onboard probably 25,000 miles, and there was always a sense of not being in control. It always felt like the tail wagging the dog. Many uncomfortable driving moments. The first couple years I had it stored in a lot next to a similar unit mounted on a 3/4 ton Ford (leaf springs, of course). I rocked both units and immediately decided that leaf springs (not Ford) were the way to go due to much less rocking, less rebound and better stability. I later used the camper on a 86 Chevy crew cab dually and it worked great. I now have a 4000#, 11.5' Lance camper on a 06 crew cab Duramax dually and will never use anything else other than a newer version.

Edit: You might consider a shorter (8' or 9' unit and perhaps also one that is narrower. This camper is 11' (floor length) long and 8' wide.

I have had campers on duallys and sing axle..dually is the only way to go...But I hate driving them with the camper off

[Prematuregrey]

Originally Posted by FirstOwner69

Here is the best picture I have on file...same truck.

Thank you sir. That's an interesting quarter elliptical setup.

[Longhorn 70]

I can tell you that wet dirt piled as high as the cab will squash leafs and the rear tires even with 60 psi in them. It also put the leafs on the overloads, made it ping and try to jump lanes.

Leaf springs were listed on my truck as H D Rear Axle.

[Longhorn 70]

Sorry, I believe the leafs are listed on the SPID as Auxiliary Spring EQ.

[FirstOwner69]

Originally Posted by Longhorn 70

Sorry, I believe the leafs are listed on the SPID as Auxiliary Spring EQ.

Longhorns came standard with leaf springs so that wouldn't be on your SPID. G60 was the option code for both the leaf and coil auxiliary springs even though the aux. spring designs were very different.

[1972RedNeck]

I had a 11' by 11' by 8" block of concrete on my truck. If concrete weighs 3800 Lbs. per cubic yd., that figures to be right around 11,353 pounds, or 5.7 tons.

It made the truck ride real nice.

[Coley]

Originally Posted by 1972RedNeck

I had a 11' by 11' by 8" block of concrete on my truck. If concrete weighs 3800 Lbs. per cubic yd., that figures to be right around 11,353 pounds, or 5.7 tons.

It made the truck ride real nice.

....a (near) 12,000lb piece of concrete....11'x11'x8" in/on your truck?

...was it in the cab with you or on the tailgate? LOL

Coley

[69GMCLonghorn]

I have to say it's beyond amazing what this gen of truck were/are capable of doing. The newer trucks are fantastic, but not 40+years-newer worth of fantastic. In terms of loading a truck, yeah, leaf's are better for the stability with a camper. But if you get the elliptical overloads, a sway bar and a good set of shocks (I swear by KYB gas adjusts, but everybody has their preference), you will do ok with that truck.

The other thing is, for basic loading of ANY truck:

1) Make sure your tires are aired up to the proper weight for the load, and not in good shape, but GREAT shape! and suited for the weight you will be carrying.

2) Load it up completely and see how the tires squat and how the suspension squats. You should be at no more than about 2/3 of the suspension travel at best for a somewhat safe ride. If it's sitting down more than that, think about some air bags.

3) Do NOT drive it like a new truck with anti-lock brakes, stability control, etc! Drive it for what it is, slow the hell down a bit when it's loaded heavy, and have fun!

[Joe Cool]

Originally Posted by 69GMCLonghorn

I have to say it's beyond amazing what this gen of truck were/are capable of doing. The newer trucks are fantastic, but not 40+years-newer worth of fantastic. In terms of loading a truck, yeah, leaf's are better for the stability with a camper. But if you get the elliptical overloads, a sway bar and a good set of shocks (I swear by KYB gas adjusts, but everybody has their preference), you will do ok with that truck.

The other thing is, for basic loading of ANY truck:

1) Make sure your tires are aired up to the proper weight for the load, and not in good shape, but GREAT shape! and suited for the weight you will be carrying.

2) Load it up completely and see how the tires squat and how the suspension squats. You should be at no more than about 2/3 of the suspension travel at best for a somewhat safe ride. If it's sitting down more than that, think about some air bags.

3) Do NOT drive it like a new truck with anti-lock brakes, stability control, etc! Drive it for what it is, slow the hell down a bit when it's loaded heavy, and have fun!

Hang Longhorn......thanks.....most I did know but a refresher course is always great!
Now I have to find a longhorn!

[69GMCLonghorn]

Originally Posted by Joe Cool

Hang Longhorn......thanks.....most I did know but a refresher course is always great!
Now I have to find a longhorn!

I wish I still had mine. I sold it a few years ago to a guy shipping it to Germany. They were going to mount TV's in the bed and drive around Munich advertising ladies of the evening... I wish I could have gotten pics of that!

[Joe Cool]

Originally Posted by 69gmclonghorn

i wish i still had mine. I sold it a few years ago to a guy shipping it to germany. They were going to mount tv's in the bed and drive around munich advertising ladies of the evening... I wish i could have gotten pics of that!

ns!