Bringing up the Rear With Currie Enterprises
The last time we saw Brass Tacks, a ‘76 GMC K5 Jimmy being transformed into a roadstered street rod over at Status in Rockwall, Texas, its front suspension was fully mocked up on a frame table. The front suspension consisted of the Quality Air Ride front raised cross member for the C-10 platform that provides clearance for the frame to lay flat, but also consists of mounts, new control arms and more. The cross member was assembled with a Flamin’ River Mustang II power rack-and-pinion, as well as a C-10 big brake kit from McGaughys Suspension that consists of drop spindles and 13-inch rotors. The goal is to build a complete frame using this as a base. The rear suspension will also need a base, which is where a Currie Enterprises rearend comes into play.
Out back, we are running 22 x 12-inch Colorado Custom Segundo wheels wrapped in 305/40/22 Toyo Proxes STII tires. The instructions we gave Colorado Custom were to give us as much lip on the rear wheels as possible, and we’ll figure out the rest! With the minimum backspacing of 4 1/4 inches we gained a massive 8-inch lip. The next step is to head to Currie Enterprises in Anaheim, California, where the crew will build a rearend to fit the wheels and transfer the power of the GM Performance Parts E-ROD LS3 engine while looking good doing it.
Currie Enterprises is a mainstay of the performance automotive world. Currie handles a wide variety of performance rear and front end styles and parts from racing to street-driven hot rods to off-road Jeeps and rock crawlers. With more than 50 years in the business, we knew we were in great hands. Currie has a wide variety of rearends for specific applications and also for custom needs. They can build your rearend or components to fit your vehicle needs. From 10- and 12-bolt GM applications to DANA front ends and the Ford lineage, you can find it at Currie.
The Ford 9-inch rearend is one of the most commonly used in the custom world. To fill this need, Currie offers a few different housings based on the Ford 9-inch format. An all-new fabricated F9 housing or newly manufactured 9-plus and heavy-duty housings are available, as well. Since Brass Tacks is a full show vehicle, we went for a jewel of a housing with Currie’s 9-inch aluminum housing assembly. The finned housing offers a glimpse of nostalgia. The cast aluminum housing has been a timeless design at Currie since the mid ‘80s. It is available in the raw cast finish or fully show polished, perfect for showing off that custom rear suspension.
An EATON TrueTrac differential with a 3.70 gear ratio will be expertly installed into the housing before 31-spline axles and disc brakes are installed. The EATON TrueTrac is a helical gear differential unit built with the street performer in mind. A TrueTrac is a strong limited slip differential designed so that there is no need for wearable parts, leaving maintenance-free traction. Many limited slip differentials sacrifice tire wear and steering control for traction. This is not the case with the EATON Detroit TrueTrac as it performs like a conventional differential until traction is lost and only then does it transfer power. In laymen’s terms, this means if one tire begins to spin loose going around a corner, the unit will control the spin and transfer power to the tire that has maintained traction.
Sources
Colorado Custom
714.441.2498
Coloradocustom.com (http://www NULL.coloradocustom NULL.com)
Currie Enterprises
714.528.6957
Currieenterprises.com (http://www NULL.currieenterprises NULL.com)
EATON Performance Products
Eaton.com (http://www NULL.Eaton NULL.com)
Status
Dept. STTR
777 Riding Club Rd.
Rockwall, TX 75087
972.772.0146
Creatingrollingart.com (http://www NULL.creatingrollingart NULL.com)
Toyo Tires
Toyotires.com (http://www NULL.toyotires NULL.com)
Project Brass Tacks
Accuair Suspension
Accuairsuspension.com (http://www NULL.accuairsuspension NULL.com)
BASF Automotive Refinish
Basfrefinish.com (http://www NULL.Basfrefinish NULL.com)
Carter Hickman Designs
Carterhickmandesigns.com (http://www NULL.carterhickmandesigns NULL.com)
Classic Industries/OER
Classicindustries.com (http://www NULL.Classicindustries NULL.com)
Energy Suspension
Energysuspension.com (http://www NULL.energysuspension NULL.com)
Firestone Industrial Products
Ride-rite.com (http://www NULL.Ride-rite NULL.com)
Flaming River
Flamingriver.com (http://www NULL.flamingriver NULL.com)
Flex-A-Lite
Flex-a-lite.com (http://www NULL.Flex-a-lite NULL.com)
GM Performance Parts
Gmperformanceparts.com (http://www NULL.gmperformanceparts NULL.com)
Grant Kustoms
Grantkustoms.com (http://www NULL.Grantkustoms NULL.com)
Hoffman Group
Hoffmangroupproducts.com (http://www NULL.hoffmangroupproducts NULL.com)
Kinetik
Kinetikpower.com (http://www NULL.kinetikpower NULL.com)
Mitch Henderson Design
Mitchhendersondesign.com (http://www NULL.mitchhendersondesign NULL.com)
McGaughys Suspension
Mcgaughys.com (http://www NULL.mcgaughys NULL.com)
Painless Performance
Painlessperformance.com (http://www NULL.painlessperformance NULL.com)
Quality Air Ride
Qualityairride.com (http://www NULL.Qualityairride NULL.com)
Royal Purple
Royalpurple.com (http://www NULL.royalpurple NULL.com)
VariShock
Varishock.com (http://www NULL.Varishock NULL.com)
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- Over at Status in Rockwall, TX, the teardown has begun. The old 4WD chassis is pulled out from under the K5.
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- With the firewall gutted, the fully assembled QAR front raised cross member is outfitted with the 22 x 8.5-inch Colorado Custom Segundo wheels and Toyo Proxes STII 265/35/22 tires and is set down in between the fenders to show the front track width. The cross member narrows the track width for proper clearance and turning.
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- Remove the rear wheel tubs and trim the area along the side of the body flat and clean so that the rear wheels and tires can be set in place.
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- The wheels are set in place matching the track width of the front wheels for the best driving and looks and so a measurement can be taken. Out back, the Colorado Custom Segundo wheels measure 22 x 12 inches with 4.25 inches of backspacing. The Toyo Proxes STII tires are a perfect fit for the wide rims at 305/40/22, and fit well with the laid-out K5. From the mounting hub on each wheel, the measurement is 53 ¼ inches.
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- We head over to Currie Enterprises in Anaheim, CA, where Brian determines all of the specs for the rearend based off of our measurements. He subtracts the axle and brake widths to get the specs to build our aluminum Ford 9-inch housing and axle tubes. Here is the center section of the housing polished to a shine.
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- The center section is placed in an oven in order to heat and expand in preparation for the axle tubes to be slipped in and secured.
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- The 3-inch axle tubes are machined down for a tight fit with the heated housing. Adhesive is placed on the ends and the tubes are slipped in and allowed to cool.
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- To further secure the axle tubes, they are drilled and tapped through the holes in the housing on a drill press.
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- The stainless button head screws are hit with Loctite and torqued to spec in the housing.
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- The third member studs are temporarily installed to use as reference points for measurements.
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- The ends of the tubes on the housing are cut down to spec with a CNC saw. Ford 9-inch rearends are an off-center design. In order to center the rearend, the tubes are cut differently to compensate.
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- The cut tubes are ground smooth and chamfered in preparation for the housing tube ends to be welded in place.
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- A mockup third member housing is set level, as well as the ends, before being clamped in place. Mockup axles are used to center the ends.
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- The ends are tacked in place and the order number is stamped on the tube.
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- Currie Enterprises works like an assembly line ensuring that each worker is an expert at their job. Measurements are double checked against the order at each step.
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- A rotating mount is used to fully weld the tube ends and any other brackets that may have been installed. The housing is first sprayed with brake cleaner and an anti-splatter spray.
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- The welds are cleaned up with a wire brush.
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- The axles are cut in-house, as well. If you are simply narrowing your current rearend and need custom axles, those can be ordered. The splines are machine cut from blank steel. We went with a 31-spline axle for strength.
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- Our axles have also been drilled for our five on five bolt pattern. You can see the difference in length to offset the differential.
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- Now it is time to assemble the third member. We are using an EATON Detroit TrueTrac limited slip differential with a 3.70 gear ratio that transfers power when traction is lost.
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- New bearings are pressed onto the ends of the Eaton TrueTrac.
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- The ring gear is secured to the TrueTrac.
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- Bearings are pressed onto the pinion gear and support.
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- The yoke is installed after pressing on the seal.
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- A pinion seal is pressed in place before the housing is greased, and the pinion gear and support are installed.
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- The ring gear and TrueTrac unit are secured.
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- The lash on the gears is set to ensure proper alignment so the gears will run smoothly. White paint is used to check the point of contact; the mark should be in the center of the gear teeth.
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- Clips are installed to secure the position of the differential in the housing.
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- Final assembly of the entire rearend begins after a thorough steam cleaning. The first order of business is to install and torque the third member studs to spec.
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- The measurements and specs are double checked.
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- The inside of the housing is cleaned using a wire brush and compressed air.
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- The breather is screwed into place.
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- The axles are mocked up to ensure that they are the proper lengths before pressing on the brake brackets.
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- The assembled third member is dropped into place and secured after hitting the gasket with sealant.
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- The axles are pressed with studs and then the disc brake brackets and bearings follow.
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- We went with a set of Ford Explorer rear disc brakes provided by Currie. The backing plate and mount are secured to the housing via the bolts, and the axles are pressed in and secured, as well.
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- The 11-inch rotors are drilled per the five on five lug pattern.
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- The rotors are secured onto the rearend.
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- The caliper and pad assembly are slipped over the rotors and secured. The brakes feature an internal parking brake mechanism. Rubber brake lines are run from the calipers and supplied with a mount that can be welded onto the tubes.
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- The housing receives a final polishing before rearend is shipped.
Tags: brass tacks, Colorado Custom, Currie Enterprises, EATON Performance Products, Energy Suspension, Royal Purple, Toyo Tires
I see you have an LS3 E-rod, what type headers are you using for this build?
Thanks for the informatiom on the headers, I purchased the exact brand and part number that are on the Brass Tacks build. Question does the weird bend on the driver side header get in the way of the steering linkage? On my mock up it looks rather strange, plus its really close to my control arm mount. Help!