While Currie keeps a large...
While Currie keeps a large inventory of assembled rearend housings in stock, our unit will be custom-built to our specified flange-to-flange measurement.
Not long ago, well, OK, maybe it was long ago, finding a rear axle for your hot rod project involved a pickup truck, a tape measure, and a trip to your favorite junkyard. Of course, just the fact that we refer to the location as a junkyard tells you it was a long time ago, as today we have either salvage yards or automotive recyclers. I still prefer junkyards and all the associated mystique that goes with the term.
But that was then, and this is now, and like most aspects of street rodding, we have graduated to better things than a rear axlehousing with unknown miles and wear, to a brand-new housing filled with the perfect gear ratio, big axles, better bearings, and flanges designed for modern brakes. The new housings are just better in every way, but there are still sizeable amounts of street rodders who view the third member in the driveline as a mystery piece. For that reason we thought it would be interesting to follow along at Currie Enterprises and see just what goes into the building of a brand-new unit.
Axles are sized to match the...
Axles are sized to match the horsepower being put to the ground. While bigger is always better, the pros at Currie can help you choose the proper axle for your application.
There are plenty of options available and the professionals at Currie Enterprises will walk you through the benefits of everything from limited-slip differentials to the proper axle size, brake flanges, and available mounting brackets.
While we will be focusing mostly on the internals, don’t discount the cosmetic advantages of a new housing. Just think, no messy disassembly, no old brackets to cut off, no rusty, pitted housing to prepare for paint, and the best part, no surprise noises emanating from the third member. Even the Currie housing is a smooth shape that looks perfect under any hot rod. But before you get ready to paint that Currie rearend, let’s take a close look inside and see just what it takes to assemble a brand-new custom rearend.
Here are the main pieces for...
Here are the main pieces for building a custom width rearend housing. The new centersection with studs installed, two axle tubes, and two bearing flanges for the ends of the tubes.
That big, long, solid bar...
That big, long, solid bar is routed through the empty gear carrier and the axle tubes slide over the steel bar for proper alignment.
This metal spacer simulates...
This metal spacer simulates gasket thickness, ensuring the axles will line up perfectly later.
The steel bar is the same...
The steel bar is the same O.D. as the axle bearing, so the axle flanges will be held in perfect alignment to axle tubes and the centersection. A special fixture holds the axle flanges in place.
An empty carrier is bolted...
An empty carrier is bolted to the centersection to serve as an alignment for the axle tubes and to prevent any chance of warping during welding.
Before the axle flanges can...
Before the axle flanges can be welded in place, special care is taken to be certain the axle flange bolt pattern is properly aligned. This is important because the brakes bolt to this flange.
A series of tack welds hold...
A series of tack welds hold the axle tubes to the centersection and the axle flanges to the axle tubes.
After checking flange-to-flange...
After checking flange-to-flange measurements, the housing is mounted in a rotating fixture and the finish welding is performed, making each weld a non-stop bead.
We opted for the T.S.D. limited-slip...
We opted for the T.S.D. limited-slip differential. This is a torque-bias limited slip that does not employ clutches and requires no maintenance other than periodic gear lube changes.
The inner carrier bearings...
The inner carrier bearings are pressed onto the differential in this large hydraulic press.
Currie has a special fixture...
Currie has a special fixture that clamps in the vise and makes tightening the bolts much easier. Torque the bolts in a cross pattern.
The pinion flange gasket is...
The pinion flange gasket is in place first, and the inside of the carrier has been coated with assembly grease before the pinion shaft is installed in the carrier.
The main caps are now installed...
The main caps are now installed and a torque wrench brings them to the proper tightening specification.
The assembled differential...
The assembled differential and ring gear is lowered into the case and rests on the bearing carriers in the case.
With the centersection turned...
With the centersection turned over, the front pinion seal and yoke is installed. Once again a torque wrench tightens the pinion nut to the proper tightness.
Setting the gear lash is critical,...
Setting the gear lash is critical, and the pros at Currie have it down to a science. A special fixture and a magnetic base with a dial indicator make the precise measurements.
And here it is, a brand-new...
And here it is, a brand-new from casting to pinion nut third member. Having everything brand new takes the worry out of any rearend problems and with proper maintenance will last the lifetime of most street rods.
The splines are cut in the...
The splines are cut in the axle, typical street rod axles are the 31-spline axles, and they are plenty strong.
With the centersection in...
With the centersection in the housing the bolts are snugged down with a wrench in a cross pattern before the torque wrench brings it into spec.
A bead of black silicone gasket...
A bead of black silicone gasket cement is applied to the housing face and to the top of the gasket.
The rear backing plates and...
The rear backing plates and brakes are bolted on, and then the axles are slipped into the tube and engaged into the differential. A little pushing and spinning will line up the splines.
Now the assembled third member...
Now the assembled third member is carefully slipped over the studs and into the housing, taking care not to damage the gasket. This chunk is heavy, so having a hoist or a helper is required at home.
And here it is, completely...
And here it is, completely new from drum to drum ready for shipping. Currie rearends seem to find their way under some of the best cars in the world, and now you know why.