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1949 Chevy Axle - In ArrearsCurrie Enterprises Builds A Stronger, Better, Brake- Equipped 8-Inch Rearend From the February, 2010 issue of Rod & Custom By Kev Elliot
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Here's what we started with:... Here's what we started with: a pair of Torino-type axle housing ends, a pair of 3 x 0.188-inch wall DOM tubes, and a stock Ford 8-inch axle centersection. This had the original axle tubes cut off and turned down so the new 3-inch ones would slide over them. When it came time to replace the closed-drive axle in my '49 Chevy-Project Purple Pig-I wanted a rearend that was strong, compact, and had brakes that would be more than accurate for the increased horsepower. Currie Enterprises put together a new 8-inch Ford axle for us, with 11-inch drum brakes, and an offset pumpkin so that the driveshaft runs straight. I went for an 8-inch over a 9-inch, owing to its smaller pumpkin as there will be limited room under the Chevy once the suspension is on full drop with the chassis C-notch, and I still have to run an exhaust system over the axle. Plus, the 8-inch is plenty strong enough for a street car. While I'm sure only a limited number of you are going to undertake narrowing your own axle casings, it's nice to see how it's done. Having said that, it's not that hard of a job and Currie even sells an assembly alignment bar under its Nine-Plus brand (www.new9inch.com), which sells brand-new 9-inch rearend components, offering everything from gear cases and mini-spools to T-bolts, bearings, gaskets, and retainer plates. If you own a lathe you could even turn up your own collars for an alignment bar. Seeing as I mentioned retainer plates, the 9-inch Ford axles are often described as having large [or Torino] bearings. This simply relates to early and late bearings respectively, with the earlier style having a larger bolt pattern on its housing ends, and subsequently the bearing retainer plates. Ford 8-inch axles all came as standard with 2 3/4-inch axle tubes, usually tapering down to 2 1/2 inches at the ends, and small axle bearings. The main advantage of the 8-inch rearend Currie Enterprises fabricated for us is that the axle tubes were replaced with 3-inch tubes-meaning aftermarket axle brackets such as those for ladder bars or four-links-will fit easily, though we didn't require that facility, and it now features the larger Torino axle bearings and housing ends, allowing the fitment of 11-inch brakes-a huge improvement both aesthetically and functionally. While the 11-inch drum brakes will likely be sufficient for our Chevy, it's good to know that these all-new brake kits use the Aftermarket Brake Configuration Standard (ABCS), which was developed to provide interchangeability. Any axle that uses Torino housing ends, 2.8-inch register (the diameter of the hole in the center of the drum) and 2 1/2-inch brake space (the distance from the outside of the housing end to the outside of the axle flange with the axle installed) can use any ABCS-configured disc or drum brake kit with no modifications. These include 11-inch Explorer and 11 5/8-inch Mustang discs, as well as Baer, Wilwood, and SSBC discs. This means a swap to discs if required at a later date will be a bolt-in swap!  Note the end of both the tube...  Note the end of both the tube and the centersection had been chamfered for better weld penetration. The tube was a snug fit over the turned-down original.  The centersection was placed...  The centersection was placed in a jig, a gear case with collars in place of the bearings bolted in place with a gasket, just like it will be when assembled, and the alignment bar pushed through the collars.  The new axle tubes were pushed...  The new axle tubes were pushed into place over the alignment bar.  Next, the housing ends were...  Next, the housing ends were installed, with stepped collars replacing their bearings.  Once leveled, the jig was...  Once leveled, the jig was tightened to hold the axle in place for tack-welding.  With the collars clamped to...  With the collars clamped to the housing ends, another tool was used to ensure they were in alignment.  The tubes and housing ends...  The tubes and housing ends were tack-welded with the alignment bar still in place, each joint receiving four welds, 90 degrees apart. This makes the casing strong enough to have the alignment bar removed and be transferred to the welding shop.  Final welding takes place...  Final welding takes place on this machine, which rotates the axle housing so each weld can be done in one continuous pass. Rollers support the opposite end of the housing.  Axle blanks await cutting...  Axle blanks await cutting to length for individual rearend requirements, after which they'll be splined and drilled in-house for whatever wheel bolt pattern is required.  All the axles start off the...  All the axles start off the same length; this heavy-duty chop saw is used to cut them to the exact length required.  Once the axles have been splined...  Once the axles have been splined (none were being done the day we visited), machined for the bearing and retainer, and drilled, the wheel studs are pressed in.  As Currie Enterprises is located...  As Currie Enterprises is located very near to our R&C offices, we were able to take the partially assembled axle over to Classic Performance Products (who were installing our trailing arm rear suspension), and tack-weld the mounting pads to the axle tubes with the correct pinion angle. Currie then fully welded the pads and placed the rearend in this huge press, which aligns the four bearings once again, in case the welding caused any warpage.  Once aligned, each completed...  Once aligned, each completed axle casing is transferred to the assembly shop with a detailed list of requirements.  The breather, with a floating...  The breather, with a floating cap, was the first component to be fitted, a small but vital part!  This jig was used to ensure...  This jig was used to ensure the axles were cut to the correct length before going any further with the build.  Once the axle length was deemed...  Once the axle length was deemed correct, the bearing retainers (arrow) were pressed into place. Note the retainer plate was fitted before the bearing.  This tool was used to drift...  This tool was used to drift the oil seals into place in the ends of the axle tubes...  ...and here's the seal in...  ...and here's the seal in place, with a little grease to aid assembly.  A thin bead of black RTV was...  A thin bead of black RTV was run around the third member studs, then the gasket was installed before another bead of RTV was laid down.  The brand-new ABCS drum brakes...  The brand-new ABCS drum brakes were installed next. Currie even makes the T-bolts that secure these to the axle.  Before the brake backing plates...  Before the brake backing plates were bolted in place, the axles were installed, with a little grease on the shaft, which will go through the oil seal, as well as on the bearing.  Now the brake backing plates...  Now the brake backing plates could be bolted down. With all the parts in hand, the whole assembly process was quick, and needs to be with the number of rearends Currie builds daily.  No, he's not super-strong,...  No, he's not super-strong, the 3.55:1 gear equipped third member was lowered into place with a hoist, which was also used to move the finished axle from the jig to its delivery pallet. With the third member in place, it was torqued down.  Finally, the brand-new drums...  Finally, the brand-new drums were installed before the entire axle assembly was loaded onto a pallet and placed in my pickup.  Painted satin black and ready...  Painted satin black and ready to be installed in the '49 Chevy, here's the rearend still on its pallet, with all the suspension components from CPP.  Currie Enterprises, along...  Currie Enterprises, along with other aftermarket companies, was instrumental in securing the ABCS, which means these 11-inch drum brakes will fit their axles, as will some Ford disc brakes, plus those from Baer, Wilwood, and SSBC, all with no additional modifications.  This is a great concept should...  This is a great concept should anyone wish to upgrade to disc brakes later on. The brakes are sourced directly from Ford, while the drums are manufactured by Currie Enterprises.
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