I have a 98 volkswagen cabrio with 146,000 miles. The clutch is def slipping. There is also a noise when I accelerate in the low gears. A few months ago it sounded like a tuba or other low brass instrument. Now it sounds more like metal on metal. Is the sound related to the clutch? If not any idea what is causing it?
That noise is the clutch going metal on metal with the pressure plate. You need to replace the clutch, pressure plate and throwout bearing right away.
If the sound is heard when the clutch is fully engaged and not slipping, it may be something else.
My old VW was making strange noises one day long ago. I thought the manual transmission was failing but it was a heat shield that was touching the exhaust pipe. Later it happened again and it really was the transmission that was failing due to low oil level. That one got by me but it will not happen again.
The clutch throwout bearing, located inside the transmission and adequately lubed by transmission oil was not a problem and was not replaced.
I’ve attached a link to a diagram of a typical clutch assembly.
The way the system works is that when you release the pedal, the throwout bearing (also often called a release bearing) is allowed to slide back on the transmission input shaft toward the tranny and lets the spring loaded radially-arranged levers on the pressure plate assembly clamp the clutch plate against the back of the engine’s flywheel. When the pads on eth clutchplate are worn off, metal slides on metal and it gets noisy.
As already stated, you need a new clutch assembly, or “clutch kit”. The kit consists of the clutchplate, the pressure plate assembly, the throwout bearing, and in some cases a new pilot bearing. It will also usually include a “pilot shaft”, which is a “dummy” tranny input shaft used to align the clutchplate while bolting the pressure plate to the flywheel. The pressure plate then holds the clutchplate tight against the flywheel while the tranny and engine are reconnected.
The throwout bearing is not inside the tranny, not lubricated by the tranny fluid, is subjected to considerable forces and wear, and should always be changed with the clutch assembly. The throwout bearing is in the same cavity as the clutch assembly.
Note that when you run metal to metal you risk scoring the flywheel and/or glazing the flywheel surface. If it’s too bad, the flywheel may have to be resurfaced, adding more cost. You are at the point where this is a real possibilty.
Water cooled VWs are different. The TO bearing is inside of the transmission, is lubed with trans lube and can be easily accessed by removing the end plate from the trans. Air cooled VWs have TO bearings as you describe.
Wierd. But I stand corrected. Mea Culpa.