Successful E30 Clutch and Timing Belt Project!!

Ever since I saw cars being built in an automobile assembly plant where I worked as a cost analyst, I was puzzled why people don’t focus more on how the factory did things, because that was probably the more efficient way, by far.

I have personally struggled with many tasks that could be done far more easily when another part were first removed, or when the paradigm changed.  “How did they do this at the factory?” became a good guiding principle for me whenever I worked on a car.

When my 1987 325 needed both its clutch and its timing belt replaced, I chose the approach where the entire sub-frame would be removed from the car, complete with engine, transmission and suspension.

Previous to that, my team had struggled with removing the transmissions off two other 325 cars, and it was a miserable task.

On the third car, it was super-easy. Removing the transmission from the engine was SO much easier and nicer with everything in the open.

It was also easier and nicer to work on the clutch and the timing belt, with everything in the open, completely out of the car. The car was many feet away, hanging from a mobile gantry that I’d bought for this purpose.

Many hoses, pipes, cables and wires needed to be undone, but that was (for me) preferable to the alternative.

I loved seeing how easily everything came apart, and how easily accessible everything was once the sub-frame had been removed from the car.  I didn’t even care if the car ever ran again. I’d proved a hypothesis that I’d been wanting to prove ever since I was 22 years old.

My tenacious technician, who prefers to remain anonymous, wanted me to have the benefit of a functioning car too, and he doggedly pursued getting the clutch, timing belt and water pump replaced, then putting it all together again and hooking everything up.  The victory is mostly his, since he did more than 95% of the work, and more than 99% of the most difficult tasks. Yet, I love seeing the basic concept having been proved.

Today, everything was finalized and I actually drove the car on the road again.  The gratitude, joy, satisfaction, pride and vindication were intense and wonderful.

It’s an open question as to whether, when it’s all said and done, this was easier than the traditional way.  I plan to keep refining this approach until it is certainly easier, because I think it fundamentally has more merit.

Things I would improve include:

  • Not removing parts unnecessarily, such as the glove box
  • Putting pans underneath the car so when fasteners or parts fall down, they don’t roll or bounce far away
  • Having a spare set of all the fasteners needed
  • Having spare parts in case things break
  • Having another car to go look at to see how things come together
  • Having cans or bins nearby so that as I remove fasteners, I can put them in a known place.  There’s a lot to be said for putting fasteners right back, but that isn’t always viable.
  • Having the right tools
  • Knowing which tool I’ll need for which task
  • Knowing what goes where, such as how to connect the fuel lines the right way around.

I’m about to get into my 325 and drive it to Reno, 60+ miles away.

Before today, the last time I drove the car was almost two years ago.

I’m happy. 🙂

Interesting Work on an E30 BMW 325

Whether it’s the E30 325, 325e, 325i, 325ix, 325es or 325is, they all use all the same wonderful M20 engine … with the caveat that if its timing belt breaks, the valves can impact the pistons and severely damage the engine.

Perform enough preventative maintenance on the timing belt, and the risk of such a problem is low.

Back325For the last 12+ years, I have owned a delightful E30 1987 BMW 325.  It recently got a big tune-up and some drive shaft work done, and I lent it to a friend who drove it for a few months.  She handed it back to me, and I drove it from Tucson, AZ to … well, about 80 miles south of my shop in Fallon, NV when the clutch gave out in the middle of the night on highway 95.  The clutch was by then slipping merrily, warning me of its impending failure, but I’d hoped I could limp it all the way to my shop before the clutch gave out but … no such luck.  A clutch replacement was due.

I ruminated on it for a year or so.  I hate working underneath a car.  It basically consists of transferring the grime and dust from the underside of the car into my eyes and onto my face. Then, a few fasteners fall into my eyes, and a few parts fall onto my face.  If I lift the car high enough to not feel cramped, then the stakes go up too because whatever falls off next has a lot of energy, and my feet become the next target.

I used to work in an auto manufacturing facility. I observed how the engine, transmission, steering, front suspension and front hubs are all mounted on the front sub-frame. When the build the car, they lift all that up, as a unit, to mate with the car.

So, for this car, my shop took this approach.  We performed the process in reverse first.  A local muffler shop removed the exhaust and drive shaft, and then my shop detached the various fasteners, hoses, wires etc. that connected the front sub-frame assembly to the rest of the car.  Next, we put a gantry over the car and lifted the car body up, away from the sub-frame.


That allowed us very convenient access to the engine and transmission.  Normally, to split the transmission from the engine requires some special vocabulary, but in this case, it wasn’t needed.

Normally, to replace the timing belt with the engine inside the car makes for a cramped work environment, with either of the two radiators, coolant or a/c, being just a few inches to the front of the action. With our new arrangement, there were wide open spaces to work in.


The things that we ended up replacing were intended to make the car very reliable as to typical points of failure:

  • Timing belt
  • Timing belt tensioner
  • Water pump
  • Both large coolant hoses
  • Belt that drives the alternator and water pump
  • Belt that drives the power steering
  • Belt that drives the a/c compressor
  • Clutch disk
  • Clutch pressure plate
  • Clutch throw-out bearing
  • Clutch pilot bearing

Additional items I might be tempted to swap out in future such situations are:

  • Alternator brushes
  • Shifter hardware
  • Front shock absorbers
  • Spark plugs

Enjoyable project! And I might soon be driving an E30 that I can cheerfully shift at the red-line without having to baby the engine or clutch.

This project also reminded me of how many things, large and small, can and do break during a project such as this, so if you are experiencing the same thing, and you need used parts, please contact us.