[LowTechRedneck]

I have an 86’ 944 n/a that had something go seriously wrong in the driveline today.

It started out simple enough, while driving I noticed an odd noise coming from the back end of the car. It sounded like a cross between the metallic rattle of a loose heat shield, and the “popping” sound of exhaust leaking around a bad gasket. So I naturally assumed I had an exhaust leak

When I got to where I was going, I tested the exhaust, and found it was not loose. I started the car, let it idle, and manually worked the throttle, I could not duplicate the noise. Checked to see if I was dragging anything from the underside, nothing showed.

On the return trip however, the noise once again reappeared. I took note of the conditions and found that it was loudest at low speed (20-30 mph) and louder under throttle (it all but went away during coasting). It seemed to be dependant on engine RPM, as braking/steering/speed didn’t effect the frequency, but pretty much constantly there, the only way to make it “go away” was to go up to freeway speed where the wind and road noise would drown it out.

I noticed no other problems, no wheel noise, no tire noise, no handling issues, no leaks and no warning gauges.

Anyway, about an hour later, I came up to a red light. When the light changed, I let the clutch out and the car moved forward about 2 feet and then the rear wheels locked up hard, hard enough that it stalled out the motor. After restarting, I was able to limp off the road, but only by “brute forcing” it, the wheels would turn about half a revolution and then apparently lock up because the car would “hop” a bit accompanied by a loud thunk each time, freeing the wheel for another half-rotation before it would happen again. Once off the road, I noted that with the car in “N” and the E-brake off, it would not roll downhill, also, I checked to see if anything had obviously “blown up” underneath, but saw no leaks or obvious mechanical damage.

I had the car towed home, and now am wondering where to start troubleshooting what went wrong. As far as I know this is it’s original transmission (5 speed, but I don’t know if it has LSD or not) and the car itself has been problem-free for the last 5 years with the only needs being the usual filters/fluids. The clutch is newish, it was replaced when I bought it and due to a short commute, I only put about 5K on the car a year.

Any ideas on what happened and where to start looking? Did I mash up my gearbox somehow? Because that’s what it sounds like. Any help would be appreciated. Mileage at the time of the incident is 181K. More details available upon request.