Rear Suspension and Differential

Well, the assembly of the rear suspension arms went with little difficulty. Fortunately I've been down this road before, so I made sure that the camber adjustment links in the top arms rotate the same way. This is a lot different from working on the off-road trucks, because those suspension arms are so much longer than on an on-road touring car.

After the suspension arms were completed, it was on to assembling the rear differential. Since they are identical, I went ahead built them both at the same time, so I could finish all the work with the heavy grease at once. Again, the differences between the off-road trucks and this car were interesting to note. In order to keep the gears from wearing, Tamiya provided some grease for packing the diffs.

Here's a helpful hint for you if you find yourself needing to build or rebuild differentials. My wife has these sticks that she uses for her manicures; I think they're used for the cuticles. At any rate, they are roughly 1/8" in diameter, and then ends are flattened like a flathead screwdriver. Using these sticks, I was able to apply the grease to the various surfaces of the diff cup, the spider gears/shafts, and the ring gear without getting any on my hands or work surface. The best part is that they're disposable, so clean up is a snap. I also used them to apply the lubrication grease for the plastic gear surfaces.

So with all the basic parts built, it came time to assemble the rear differential. Installation was a breeze. The only tricky part was getting the front pivot points for the suspension arms lubed and kept in place while getting the diff cover on over the rearpivot points which also had to be lubed. With the cover in place, it was a simple matter of screwing down the cover part. It should be noted here that extra care should be taken when tightening screws that are going into ABS plastic, as it doesn't take much to strip the hole. Fortunately the screw I over-torqued is in a fairly safe place that shouldn't adversely affect the rigidity of the car. If there are problems later, it's nothing a little dab of thick CA glue won't fix.

Unfortunately at this point, progress came to a screeching halt as I discovered the first stumble in the Tamiya kit. The instructions call for two small metal plates to be glued to the rear skid plate, but they did not furnish the adhesive. I thought this was rather surprising considering they included the light and heavy grease as well as the oil for the shocks. I'm not sure what these plates are for, but I'm going to use some jewelry metal glue that my wife uses in her hobby. Gotta love crossover uses for household items, right? So once I get these plates glued down, I'll be ready to finish assembling the rear.