Height differential when removing leaves on the leaf springs...

[Super_Dave]

On my C20 project, I will be adding the 2.5" C20 to C10 5 lug drop spindle conversion kit.

I will be removing the 14 bolt rearend and installing a 12 bolt, removing the C20 the overload springs on the back as well.

Then I will be removing some leaves from the C20 spring pack. What I need to know is:

1. After the overloads are off and I start to remove leaves from the spring pack, how much will I lower the back for each leaf removed from the pack.

2. Are there any recommended leaves to remove or keep as I decide how many to remove.

My goal is to determine whether to add drop coil springs to the front to even out the drop or can I control it with the just removing certain leaves from the spring pack and deleting the overload springs.

I currently have 235-85-16's on the C20. That gives me a total sidewall of 15.7" and a total wheel-tire height of 31.7" and tire width of 9.3".

I plan of going with 285-40-18 in the back with an 8.9" total sidewall, 26.9" total wheel-tire height and 11.2" tire width. I will net -4.8" in total wheel-tire height.

I plan on going with 215-50-18 in the front with an 8.4" total sidewall, 26.5" total wheel-tire height and 8.5" tire width. I will net a -5.2" in total wheel-tire height.

So, keeping these numbers in mind, I am trying to estimate the number of leaves to remove and if I will need drop coils in the front to keep the truck level or with a very slight rake.

Thoughts or criticisms welcome...

[slotard]

I have a C20 Camper Special and will be swapping in a leaf pack with a few springs removed, I can measure for you if you want. Won't be for at least a couple weeks though.

[Super_Dave]

Originally Posted by slotard

I have a C20 Camper Special and will be swapping in a leaf pack with a few springs removed, I can measure for you if you want. Won't be for at least a couple weeks though.

That would be great. Does yours still have the overload springs as well? Looking forward to seeing how much it drops after you remove what your planning to take off.

[slotard]

Overloads are gone. I'll take a picture of the new pack tonight. Still need to clean/paint the axle and then decide on discs though.

Also, I imagine the 12 has smaller tubes than the 14 and will lower you a hair too.

[N2TRUX]

Super Dave, I have never done a C/20 conversion, but I can give you some insight. If the spring pack is still located on top of the axle, removing the overload will net the thickness of the spring in drop. From that point there is no set formula on what leaf nets XX drop because of the potential wear on the springs.

If it were me, I would replace them entirely with a C/10 pack for better ride. If you prefer to keep them. run a lowering shackle. If you need more drop, move your spring hanger up on the frame.

[Super_Dave]

N2TRUX

Yes, the springs are on top of the axle.

I believe an earlier post mentioned that the C10 springs were shorter, is that your experience as well?

Would I need to drill new holes for the C10 springs or is this another one of those "the holes are already there" situations...

[N2TRUX]

Originally Posted by Super_Dave

N2TRUX

Yes, the springs are on top of the axle.

I believe an earlier post mentioned that the C10 springs were shorter, is that your experience as well?

Would I need to drill new holes for the C10 springs or is this another one of those "the holes are already there" situations...

You will need to measure your leaf pack to verify. There are two different C/10 lengths, so one might match yours. If you move your stock hanger up you gain about 1.5" drop. You will have to drill out the rivets, and use bolts to reattach.

[1970pelle]

I have done a lot of spring work over my many years of turning wrenches. N2TRUX Has given you good direction on install C10 leaf springs.

But if you want to keep the C20 and give them a try. Do pull the overload spring, you should find some spacers there also. Last one I had apart dropped it a good 2 1/2 inches. Now the right leafs to remove to drop and have somewhat of a decent ride is the shortest leafs first. Common sence plays here, the longer springs have more flex. But the C20 leafs are 2 1/2 wide ? I'm pretty sure, and about a 1/4 thick. So if you left the C20 main in place and built off it with C10 leafs that are the same with across, but thinner. Using the longest leafs first of course and build from there. I'll bet 4 to 5 leafs will get you where you need to be. And have a decent ride and haul the Saturday Home Depot run.

[tinydb84]

I had the spring pack that Slotard is installing. I removed the following springs. I installed 4 inch lowering shackles and hangers at the same time. It netted me about 6'' of drop with the combo. The ride was MUCH better thought I didn't drive it a lot before I tore it back apart.
Stock pack.

Removed springs.

I replaced the center pin at the same time.

Just removing the leafs will likely get you level depending on the condition of your springs front and rear.

[Super_Dave]

1770pelle

Thanks for the info! I am moving in the direction to keep the C20 springs to start with.

tinydb84

Thanks for the photos. Did you buy a new center pin or make one from threaded rod?

Back in the day, we use to put thin Teflon or Delrin strips between the leaves... anyone still do that these days?

Good stuff, thanks!

[tinydb84]

Originally Posted by Super_Dave

1770pelle - tinydb84

Good stuff, thanks!

tiny... did you buy a new center pin or make one from threaded rod?

Bought one. It is just an allen head screw.