I’m trying to plan things better so as to make the shop-for-used-parts process more intuitive.

The typical BMW has hundreds of parts that BMW owners might buy. For a buyer to pick these from a list is a tedious process. Some vendors, like the RealOEM BMW parts-selling website or the ZF spare parts catalog for a particular transmission, display a drawing that shows the parts essentially hanging in mid-air in their relative orientation but pulled away from each other. A simple numbering scheme in the drawing helps the buyer map an item in the drawing to the relevant detailed parts listing. This is clever and intuitive, but … still not ideal.

Why? Because the parts tend to be grouped by proximity or function, and that doesn’t always work well.

For example, let’s say you’ve driven your E30 into the back of a truck. So, now you need body parts, electrical parts, trim parts and (if the condenser was damaged) also A/C parts. When you buy due to such an event, I’m trying to enable you to find everything you’re likely to need … conveniently in one place, instead of having to go piece everything together from different paper pages or Web pages.

The ZF 5HP-24 transmission was never used on an E30, but it is a good example of what I mean. It’s a good transmission, but after 15 years the pressure regulator in the valve body has gradually worn the bore ever larger, and then fluid pressure is no longer regulated as designed and the pressure increases beyond what the clutch A drum can handle, and the drum self-destructs. Suddenly the transmission doesn’t have a functioning A clutch drum any more, and its only functional forward gear is 5th gear.

To fix this, a rebuilder needs to remove the transmission. This enables easy access for removing the torque converter, which by then probably needs a rebuild anyway due to wear and tear on it, otherwise or it might well be the next cause of catastrophic failure.

The oil pump needs to be pulled out, some seals have to be replaced in that area, and the A clutch drum needs to be replaced. So does the root cause: the pressure regulator valve in the valve body. Hence, also the oil pan gasket and filter. Functionally and as to where these parts are in the transmission, they’re quite different and the spare parts catalog shows them, accordingly, on different pages of the catalog. However, to address this very common way of failing, the list of typically needed parts really could all be listed together to make the shopping process easy for someone whose transmission has just failed in this way.

A second E30 example might be if someone buys an E30 with a missing glove box. The buyer would need the bin, but almost certainly also the hinge at the back, and the lock and latch, and possibly the clips to hold the side cable in position, possibly the two hangers, possibly the hinge-to-bin fasteners, and possibly the hinge-to-car-body nuts.  So, showing these together would make it more convenient for such a buyer.

A third E30 example might be someone who had their timing belt snap on their M20 engine.  So now, they need … probably the head, and possibly a few valves and a few rocker arms.

A fourth E30 example might be someone who is replacing the convertible top and they have a replacement canvas/plastic piece, but they are finding that some of the metal pieces on their car are bent out of shape and really should be replaced. So now, they need … things that you probably have to go piece together from multiple drawings on the RealOEM website.

Convenience in buying is what I’m trying to enable here: having parts type records grouped together in a sort of family, with that in turn linked to some or other event that drives the buying process.

Even though a family of parts type records would (of course) have multiple parts type records, the converse is true too: a particular parts type record like a front bumper might be bought for one of many reasons:

• the car was in an accident, or
• the car is generally being spruced up, or
• the car is being given a later-model-year look, or
• the car belongs to a San Francisco owner who’s tired of the demolition-derby mindset of people who have no qualms about trashing each others’ cars while parking and so a big, protruding aluminum bumper is perfect for that.

Implementing this change is no small task, but I’m very tempted to proceed.