In the grand theme of things it has been opinioned one of the big distinctions between styling philosophies guiding General Motors' truck and automobile designs of the '50s and '60s was the annual model change where GM cars got a major facelift while the trucks received a few new emblems and that was it. Putting styling aside and moving on to a discussion purely of truck engineering advancements brings us to the second installment of the brake and suspension modifications we've been making to our '66 Chevy C10. For those of you who missed the first installment we joined forces with KA Custom and Early Classic Enterprises to make our upgrades using a hybrid mix of Early Classic's high-quality lowering springs, trailing-arms, and spindles combined with '73-87 Chevrolet C10 heavy-duty F44 brakes. Because of General Motors' practice of including interchangeability into the plan the 5- to 6-lug bolt-pattern swap we made up front was in the cards for the rear end as well. The '66 C10's 12-bolt differential that left the San Jose, California, GM truck plant in'66 at the core of this conversion is retained thanks to a pair of 5-lug axles from Early Classic Enterprises. Once the axles were in place the next step for Steve at KA Custom was to install the bigger F44 drum brakes also sourced from Early Classic's catalog of new parts.
Beyond the motivation of being able to select from a greater choice of wheel designs with 5-lug bolt patterns, the adaptation of F44 drum brakes with their greater surface area than stock '66 brakes means the truck will be able to stop faster. It's one of those an ounce of prevention is worth more than a pound of cure situations when one weighs the cost of stopping in time, or having to pay up for compacting someone's car into an accordion. Sleazy PI attorneys, and missed days at work in court aside the ability to stop on a consistent basis makes a classic truck much more pleasurable to drive.
In addition to installing Early Classic's 5-lug big-brake conversion kit with 5-lug axles, we used Early Classic's 6-inch drop kit that is engineered to increase the handling of our '66 thanks to a full-width Panhard bar (also known as a Panhard rod, or track bar) and relocated shock absorber brackets that mount the shocks in a more upright position to enhance function. Check out the last photo in this article and you will see using Early Classic's 2 1/2-inch drop spindles with 1 1/2-inch drop coils up front (Covered in the March issue) along with their 6-inch drop kit for the rear laid our bad boy '66 down on the ground with a 4/6 drop.
Here's the stock '66 rear...
Here's the stock '66 rear suspension complete with six-lug hubs and narrow drum brakes. Notice the stock Panhard bar extends from the driver's side framerail to the top of the differential.
When Steve at KA Custom removed...
When Steve at KA Custom removed the stock brake drum he discovered the rear axle seal leaked and had soaked the brake thoroughly with hypoid gear oil. Steve suggested taking a photo of the brakes at this point to use as reference to assemble the big brake setup from Early Classic Enterprises.
Steve laid all of the Early...
Steve laid all of the Early Classic brake parts out on a tabletop to account for each one before starting. The next step was to familiarize him self with the directions.
To lower the rear suspension...
To lower the rear suspension six inches we used Early Classic's full-width Panhard bar conversion kit, which accounts for the drop along with special lowered KYB shocks as part of Early Classic's big-brake upgrade. Here Steve is seen disconnecting the rear shock absorbers brackets to drop the rearend down.
Besides repositioning the...
Besides repositioning the Panhard bar, the Early Classic drop kit also accounts for the shock angles necessary by providing upper and lower shock relocating brackets. Due to 40-plus years of rust Steve had to cut the original stock upper shock mounts from the frame.
This is how the Early Classic...
This is how the Early Classic top shock absorber relocating bracket appeared after Steve bolted it into place. Note the Grade 8 hardware included in the ECE kit.
Here Steve is seen attempting...
Here Steve is seen attempting to unbolt the stock Panhard bar. Notice the stock location for the Panhard rod mounting point on the top of the differential.
After the impact wrench failed...
After the impact wrench failed to loosen the Panhard bar's mounting bolts, Steve resorted to cutting the bolts off with an abrasive cut-off wheel on a pneumatic die-grinder.
Because Early Classic's Panhard...
Because Early Classic's Panhard bar interferes with removing the differential cover, Steve's next step was to remove the differential cover and began to exchange the stock 6-lug axles for Early Classic's 5-lug axles. After removing the twelve bolts holding the diff cover in place Steve dislodged the cover with a mallet and flat-bladed chisel.
Steve's first step to removing...
Steve's first step to removing the stock axles was to position the ring gear with the 9/16 hex-headed setscrew at 11 'oclock looking at it from the passenger side rear 6-lug axle flange. He then used a 9/16-box wrench to unbolt the right-hand threaded setscrew.
He then rotated the ring (sun)...
He then rotated the ring (sun) gear forward (clockwise, viewing from passenger side) by turning the axle flange until the retainer pin could be extracted from the bottom at 5 'oclock viewing from the passenger side.
Steve said to make absolutely...
Steve said to make absolutely sure CCT readers understood the spider gears can fall out of place and cause a lot of grief if care isn't used while removing the retainers from the axle ends inside the spider gear cage.
To dissolve 40-plus years...
To dissolve 40-plus years of hypoid gear oil sludge Steve sprayed on aerosol parts wash and then flushed out the entire differential housing until it was clean as possible.
Here's a close-up view of...
Here's a close-up view of one of the two axle retainers found on the inside of the spider gear cage. Be sure to inspect the axle retainers for minute cracks.
Notice the hypoid gear oil...
Notice the hypoid gear oil wetness created on the axle at extreme left by the leaking axle seal. At right is the pair of beautifully machined 5-lug axles from Early Classic Enterprises.
Here's how the rearend gears...
Here's how the rearend gears appeared with the new 5-lug axles installed. The white substance is white lithium grease Steve applied to the inboard and outboard sides of the axle ends.
Before replacing the 12-bolt...
Before replacing the 12-bolt differential cover Steve cleaned it thoroughly with an aerosol parts wash and scraped every last trace of the original gasket.
To adhere the 12-bolt diff...
To adhere the 12-bolt diff cover gasket and help to ensure there wasn't a leak between the cover and the differential housing Steve used a caulking gun to apply brand name sealant The Right Stuff.
With the installation of the...
With the installation of the 5-lug axles completed the differential was topped-off with Royal Purple SAE 75-90 synthetic gear oil. Notice the silver KYB lowered gas shock, and Early Classic's black 6-inch drop-coil mounted in place.
After the stock Panhard bar...
After the stock Panhard bar was removed, Steve test fit the new Early Classic Panhard bar and discovered he needed to spread apart the opening (mouth) of the stock Panhard bar mounting-bracket.
To help eliminate the possibility...
To help eliminate the possibility of squeaky bushings on the Early Classic Panhard bar's bushings Steve applied Energy Suspension Formula 5 Prelube, which is a versatile, waterproof, non-melting grease containing Teflon.
This is how the full-width...
This is how the full-width Panhard bar from Early Classic appeared after it was installed. Notice the passenger side mount is a special bracket included in Early Classic's kit that attaches to the Early Classic trailing arm (See December '08 CCT for T-arm install) and doubles as a shock absorber lower mount.
Flashing back to removing...
Flashing back to removing and replacing the stock early C10 rear drum brakes with Early Classic's F44 big rear brake conversion we see Steve's first step of removing the four backing plate retaining bolts with an air impact wrench... Snap-on to be exact.
Notice the expanded prongs...
Notice the expanded prongs on this emergency bake cable? These need to be collapsed in order to swap the e-brake cable from the old to new backing plates.
As witnessed by this photo...
As witnessed by this photo of Kevin and Steve wrestling with it, removing the e-brake cable from the backing plate can be a major struggle. The three of theorized there must be a special tool. Ultimately the two triumphed by collapsing each prong individually.
This is the late C10 roller...
This is the late C10 roller type axle bearing that replaces the early C10 caged ball-bearing type axle bearing. The newer style 5-lug axle with a raised surface on the outboard side serves as the inner race. Steve pre-lubed the bearing with white lithium grease.
Steve and Kevin highly recommend...
Steve and Kevin highly recommend applying The Right Stuff to the outer edge of the axle bearing to ensure gear doesn't leak into the brakes.
This is how the axle bearing...
This is how the axle bearing and axle seal appeared after Steve installed them with a bearing and seal driver. Note the late model style C10 F44 backing plate is a direct bolt-on.
Steve assembled Early Classic's...
Steve assembled Early Classic's F44 big drum brake conversion by using the early C10 brakes as an example. Both early and late brakes use the same self-adjusting setup that is activated by engaging the emergency brake. Note if you don't use the e-brake the rear brakes will not stay adjusted.
The brake drums did not fit...
The brake drums did not fit over the 5-lug axle flange the first try. Steve carefully hogged the center out until the drum slid snugly over the flange.
This is how the brake drum...
This is how the brake drum fitted to axle flange appeared after Steve was satisfied with the fit. He then cranked-out the brake adjustment until the shoes dragged slightly. Detectable by feel, and an audible scuffing sound.
When it comes to brakes, cleanliness...
When it comes to brakes, cleanliness is next to godliness (insert deity of choice here). Steve flushed the brake shoes and brake drums before they went together for the final time.
Like we said, our '66 looks...
Like we said, our '66 looks like a real bad boy slammed down to a four-six drop, and with 5-lug big-brakes to boot!