When I bought this truck it was already lowered, but the lowering was done carelessly by heating the rear springs, and not very well at that. One front spring had a coil cut from it while the other was apparently heated also.
All this made for a ride that was less than ideal. I decided to finally take on this challenge and change out all 4 springs. I wanted similar ride height, just with new springs. I could not find the dimensional information I needed to decide which lowering I needed to get the same or similar height. After much searching, I finally found and calculated what I though would be original manufactures ride height. This helped me calculate that what I had was approximately a 3″ drop in front and a 5″ rear drop. I shopped for only a short while to find a great deal on eBay. A set containing both front and rear pairs for one great price.
Removing them was pretty straight forward. I had to cut one rear spring and bolt because of a damaged bolt and retainer.
Then I found that I would need new rear spring retainers as at least one of the originals was damaged. Closer inspection found that the panhard or trac bar had also been “modified” by heat to compliment their “custom” lowered springs. I’ll include a new adjustable trac bar while there.
The previous owner had also converted this to a 5 lug setup front and rear. While the did a correct job on front by using a later model (73-87) C10 spindles, hubs, rotors etc, They did the rear incorrectly by using the incorrect axle shafts. They swapped in 31.5″ shafts (88-91 truck) making the axle 3/4″ too long. It worked, but caused the drum to sit away from the brakes so that only 2/3 of the shoes were touching the drum. Not ideal. I was going to have to change them out at some point soon anyway. Since I was working on the rear suspension I thought I’d do some shopping for the axle. I found it on Ebay for about 75% of Summit price in an open box deal. Axle shafts, lugs, bearings, seals, drums in one kit.
This also means new rear brake shoes. I was already planning new ceramic pads in front to cut down on the nasty brake dust, so new brakes all around. See previous post for more about the Brake System Overhaul.
Also replacing the worn upper ball joints. The tie rod ends should be replaced soon. While reconnecting the passenger outer ( you have to disconnect to install springs) The threads were damaged. If I have to replace it, I may as well replace them all. Left. right, inner, outer. New shorter bump stops also installed.
Hey, while we are at it, we’ll retrofit a 1979 C10 front sway bar. More on that in the next update.
All in all, it was rather simple, though a bit time consuming.
Trailing arm bushings will happen soon.
3″ Front/5″ Rear lowering springs: Ebay specials from sae_speed
3″ Rear lowering springs: CPP RCS603-3 from Summit
Rear spring retainers: CPP RCR-K
Adjustable Trac Bar: CPP 6572DATB
Brake shoes: Powerstop B449
Rear axle shaft kit: Yukon G6569RACK
Upper ball joints: ACDelco 46D0024A
Rear trailing arm bushings: Energy Suspension 3.2123G
Front Shocks: Monroe 59041
Rear Shocks: Monroe 59001
Front Bump stops: Moog K6598
Brake pads: Wagner ZD52, ceramic
Inner tie rod end: ES409LT
Outer tie rod end: ES409RT