Trailing Arm Rebuild Part 2 - Rebuild and assembly

 

We left off in part 1 with the trailing arm fully disassembled and ready for paint. Here are the parts after a few coats of paint. This is also a good time to clean up the frame a bit and splash some paint on it as well.

 

Let's start the rebuild... The "brute force" brand U-joints  were only a few years old but showed some definite wear. There should be no wear marks whatsoever on the shaft yet as can be clearly seen in picture one, this one looks pretty bad. I decided to replace them with Spicer brand U-joints and was impressed with a side-by-side comparison. The Spicers look significantly stronger, don't they?

 

Back to the spindle hub it is time to install the new bearing races. I found this tubing bender happened to have the correct diameter to protect the race while I tapped it in. The outer race is easy as the old inner race can be used for installation. The inner race is slightly smaller than the outer and makes a perfect installation tool. Be absolutely sure to fully drive the races home as otherwise the bearing play setup will be all wrong.

 

The parts making up the spindle. The outer bearing has already been pressed onto the new spindle. Yes, I replaced the spindle. It makes no sense to me to go through all this work just to put a 30+ year old spindle back. These spindles weren't the best to begin with as they were designed for 327 cui engines back in the early 60's. With today's engines usually producing much more torque than that a factory spindle becomes marginal. Add 30 years of thermal cycles and good old metal fatigue and you have a disaster just waiting to happen. I got a set of new (not reconditioned) spindles made with better quality steel than stock.

Back to our assembly. As I said, the outer bearing is already pressed on, but don't forget the dust seal that goes on first. Next we'll go from right to left:

Setting up the bearings isn't all that hard, just time consuming. I like grinding out the inner bearing so that it is a light press fit. I still use the press to take it apart, but it comes apart easily without any fuss. I then assemble the hub with the old shim and measure the play. The spindle nut has to be torqued to 100 ft-lbs for the measurement to be accurate. For some mysterious reason I haven't figured out yet, the play always increases 0.002-0.003 when I grease the bearings so I get it close with the bearings dry and then grease them up for the final shim selection. I set the play at no more than 0.002", with 0.001" to 0.0015" preferred. Decreasing the shim thickness decreases bearing play.

The second picture shows the hub ready for the final assembly. Bearings have been packed with high-temp moly grease, and the brake shield is installed. The shield has to go on before the spindle. Also note that one of the parking brake locating pins is installed now as it is very difficult to do after the spindle is on.

 

With the spindle pressed in the inner dust seal can be tapped in place and then the dust shield. Next is the flange which is held in place by the spindle nut torqued to 100 ft-lbs. The nut is then tightened further until the cotter pin can be inserted.

 

The final part to be replaced is the trailing arm bushing. The aftermarket poly bushings can be installed very easily, but the stock rubber bushing is a little trickier. The bushing comes in two halves. While the bushing is compressed, the inner sleeve has to be staked. Of course there's a special tool for this, but I got it done with some improvisation. ON the bottom you see a common bearing separator that I use to press bearings on my press. On top I used the old bearing shell. Then I added a regular harmonic balancer puller. By tightening the two bolts the bushing is compressed. I can then tighten the balancer puller to put force on the sleeve. I alternately tighten the puller and smack it with a hammer.

Here you can see how the inner sleeve has been staked holding the two halves together while properly compressing the rubber. With that out of the way the rest of the trailing arm can be reassembled. The parking brake will take some patience... Final picture shows the trailing arm ready to be put back on the car.