Eta-engined E30s came equipped with either a 2.79:1 or a 2.96:1 differential. Not many of them came with limited-slip differentials. For added acceleration, many Eta owners choose to swap in a 3.25:1 limited slip diff from an E28 533i or 535i. Picture the lower (higher numerical) diff as a longer lever arm that acts to increase the engine’s effective torque on the rear wheels. Additionally, the limited slip clutch pack means that you generally can put power to both wheels instead of just one.
Parking my car one night a few months back, I heard a groaning from the engine compartment, followed by a large increase in steering effort. Getting out of the car, I discovered a nice big puddle of power steering fluid sitting on the pavement where I was — my steering rack had blown a seal. As an interim measure before replacing the rack, I removed the belt driving the power steering pump; this hopefully prevented any great damage from the pump running dry.
At the same time we replaced my exhaust, we changed my transmission fluid. I used LubroMoly gear oil for the change. The early Eta transmissions seem to be different from later E30 transmissions, as the drain and fill plugs were both removable with a 17 mm socket (instead of a 17 mm hex driver). First, remove the fill plug. This insures that you have a nice stream of oil from the drain plug by allowing air to enter the case to replace the oil. Put a drain pan underneath the drain plug, and unscrew it. Let the oil drain out, and then replace the drain plug. Use a pump to move the new fluid from its container to the tranny – it will save you needless aggrivation. Once you’ve filled the transmission to the point where fluid starts pouring out of the filling hole, you can re-install the fill plug. Your transmission will likely take about 1.7 liters of oil.
The new fluid, being synthetic, has made a huge difference in shift feel. Shifts feel much more natural, and much less notchy. It hasn’t gotten cold here yet, but one of the benefits of synthetic gear oil is reduced cold-shifting effort.
Earlier this year, my stock exhaust developed a hole in it. As the year went by, the “sporty” sound became less and less enjoyable – especially after extended highway driving! In replacing the exhaust, I had several options:
- Replace with a factory exhaust, $300
- Replace with an E30 325i exhaust, necessitating an new cat, ~$800
- Replace with an Ansa exhaust, $150
- Replace with a Supersprint exhaust, $500
BMW factory speakers aren’t the best to begin with, and as they were over a decade old on my car, they were starting to buzz whenever the stereo sent them a low frequency. Looking through the Crutchfield catalog, I decided on the Kenwood KFC-1386 speakers. These 5 1/4″ speakers have a wide frequency response, and were resonably priced. Although Crutchfield doesn’t list these speakers as fitting the E30, they do.
Installation is fairly simple. First, remove the old speaker grilles; they should pop right out. Then unscrew the old speaker, and remove it from the housing. Pull off the wires and install them on the new speakers with a thin coating of dielectric grease for good measure. Screw in the new speakers, but don’t crank the screws down. Install the grille, and you’re done! The driver’s side is the trickiest part, as the hood release lever is in the way. You just have to hold it out of the way as best you can when removing and installing the speakers.