Subscribe to the Free

Firm Up Your Rearend

Way Cool Camaro Rear Diff And Suspension Upgrade

Grant Peterson Sep 15, 2005

It seems as time goes on, we don't have to make as many hard decisions, in day-to-day stuff that is. We can have things "our way," as one place likes to say. Oftentimes, we can get the best of both worlds without much of a compromise. This goes beyond fast food and runs rampant in the automotive aftermarket. You want a reliable small-block with big-block cubes? You bet. Wanna build a car that not only goes fast in a straight line, but handles like a sports car too? No problem. How about a tough-as-nails rearend that bolts in and shares good design ideas from several auto makers, improved leaf springs to go along with it to help the stance and the ride, top it all off with better brakes, and that pretty much rounds out the backside of your car.

That is where we're at with the build on this '71 Camaro as it gets closer to seeing the light of day. The rearend is a new Moser Engineering 12-bolt with an Eaton Posi and Ford 9-inch axle housing ends that uses the big Ford bearing, and eliminates the need for C-clips in the center section. With all of that, we still retained the stock brake bolt pattern, but you can also change that if you like.

The Hotchkis springs reduce roll and axle- wrap, they increase handling and perfor-mance, and also lower the car. These leafs come with heavy duty shackles, U-bolts, spring pads, and nut clips, and are designed to work on both mono- and multi-leaf-equipped vehicles.

In the brake department, we opted for the performance of rear disc brakes with a simple rear drum brake upgrade. This kit from Master Power Brakes duplicates a special heavy-duty rear drum option from GM. The larger finned drums with the big high-performance matrix ceramic shoes will greatly increase the stopping distance and don't require a special four-wheel-disc master cylinder, booster, or valve. The drum brake backing plates come pre-assembled, so all you will need to do is remove the old brakes and bolt on the new ones. However, with the bigger axle ends there was a little modification that was necessary. But it was not a big deal, since that's where we finally had to compromise.

All of this was done on a lift, so you may need to plan your steps a little differently if you are doing the install on the ground. But everything that has been done here could be done in your garage with an air compressor and few tools. Also, I mention and use some parts from Performance Online's Traction/Cal-Tracs Bar kit that we'll be installing soon. They are not your traditional traction bars--these things really work!

All of these companies have great parts to work with many makes and years to suit your needs. So read on and stay tuned.


This '71 Camaro is going to spend a day at the gym to build up its underside.

Here is the beautiful new Moser 12-bolt rearend with 9-inch housing ends. Doing this eliminates the need for C-clips in the center section, and adds strength, reliability, and ease of maintenance.

This is the Master Power Brakes 11-inch rear drum upgrade kit for midsize GM cars from '64-'81. You can see how much bigger these brakes are compared to the stock binders when you get them side by side. This is normally a bolt-on stock replacement that includes the drums and complete rear brake assembly.

The Hotchkis spring kit utilizes a 3/4 length overload spring, reducing axlewrap and features urethane rear bushings and rubber front bushings, offering both performance and comfort. Included are heavy-duty shackles, U-bolts, spring pads, and nut clips. The kit also lowers the car 1.5 inches from stock.

This is Performance Online's Traction Bar kit that will be fully installed later; we will be using some parts from it for now.

With the car up in the air, we can see the stock greasy 10-bolt rearend. Start by squirting every nut and bolt with penetrating oil that will be involved in removing the leaf springs and rearend parts. If need be, do this well in advance.

With the driveshaft removed, I started by taking off the nuts from the lower shock mounts and U-bolts. Also disconnect the brake lines at the wheel cylinders and rearend.

After taking the drums off, disassemble the brakes so the emergency brake cable can be unhooked and removed from the backing plate. At this point, the rearend should be just sitting on the leaf springs with nothing else attached to it.

With the car lowered back down, I unbolted the front leaf spring pocket, dropped the front of the leaf springs down, rolled the rearend forward, and put the car back up in the air, minus the old rearend.

Here is the front leaf pocket removed from the car and the leaf spring. The Hotchkis springs come with new Grade 8 hardware so set aside or discard the old hardware.

Luckily, the new hardware includes the nut clips for the front spring pocket mount since four of the six old ones broke upon removal.

Once the old leaf springs have been removed, it's time to clean up the bushing holes and install the new Hotchkis urethane bushings in the rear. This shot is looking toward the rear of the car from underneath. Use the supplied grease to lube the bushings and press them in as far as you can. I used one of the new shackle bolts with some big diameter washers and tightened it down to press the bushings in the rest of the way. Once that was done, I was able to hang the new leafs from the rear of the car by installing the new rear shackles.

Here we see the front leaf spring mount on the driver side. Thankfully, the Hotchkis springs are labeled clearly. The three mounting bolts for the removable spring pocket are visible in this shot. Attach the spring pockets to the front eyes of the leaf springs and then bolt up the pockets to the car. With both of the new leaf springs installed, I lowered the car down and jockeyed the Moser rearend into place, then raised the car back up. Keep in mind that I am doing this install with a lift and you may have to do things in a different order if you're using jackstands.

We're gonna jump ahead just a little here. In the near future this car will be getting Performance Online's Traction/Cal-Tracs Bars installed. So, with the reassembly of the rear suspension components I'm going to use the U-bolt/shock mount plate from the Performance Online kit. If you are going to use the stock plate, you will need to drill the U-bolt holes out to 5/8 inch.

With the Moser rearend bolted in place, the next phase of the project is to prep for the installation of the Master Power 11-inch rear drum brake upgrade kit. Under normal circumstances this would be just a remove-and-replace install. But since the Moser rearend got stepped up to the 9-inch bearings in the end of the axle housing, the center of the Master Power backing plates needs to be opened up so that the bearing will fit through the center. I measured the I.D. of the end of the housing with the caliper...

...and the I.D. of the backing plate. We need 0.350 inch more taken out of the I.D. of the backing plate.

If we bump it up to 0.400 inch that gives us a little room to work with, so take your calipers and lock them open at 0.200 inch and use them as a scribe around the I.D. to get a nice, even line to work with.

I grabbed my straight die grinder and a grinding burr to do the job. Go evenly around the hole and sneak up on the line. When you get up to the line, deburr with a file and/or sandpaper and see if it will fit over the bearing without damaging the O-ring. Don't forget to plug or cover the inlet to the wheel cylinder before doing all this.

Once they fit, clean off the brakes, slide them over the axle, and grease the bearing and the machined area behind it where the inner housing seal will sit, then slide that on. This is what it should look like upon final insertion.

Try to support the axle while inserting it into the housing to not only line up the splines in the center section, but to also prevent any damage to the seal and O-ring. Once the axle is in, slide the retainer in place and you can start the nuts on the T-bolts. Evenly tightening the retainer down will seat the axle all the way into the housing. During all the excitement remember to put the backing plates on their correct sides.

Do yourself a favor and if you don't already have basic brake tools, go get some! We have to disassemble the brakes to hook the emergency brake back up. You may need to use the other side for reference during reassembly.

Since the Moser rearend has bigger than stock lug studs, the Master Power 11-inch drums need their lug holes drilled out to 9/16 inch. Then slide 'em on!

Check those things out! They're huge! For the time being, I just hooked up the stock brake line until the rest of the brakes are done.

If Moser's rearend is as strong as it is good-looking then we're in luck!

Whew, it's back on the ground and everything looks like it should. Do a final tightening of everything with the weight of the car on the suspension and you're good to go.


Hotchkis Performance
Santa Fe Springs, CA 90670
Master Power Brakes
Mooresville, NC 28117
Performance Online
Fullerton, CA 92831
Moser Engineering
Portland, IN 47371

Connect With Us

Get Latest News and Articles. Newsletter Sign Up

sponsored links

subscribe to the magazine

get digital get print