924 Torque Tube Rebuild #2 - Porsche 924, MG B, MG B v6, Saturn SL2 team information

924 Torque Tube Rebuild #2

The torque tube is, at it's heart, a driveshaft supported by three or four ball bearings. Over time these bearings can expire and require replacement. The instructions below are compiled from notes from Eric Wiebrecht on the replacement of these bearings which is about all a rebuild consists of (in addition to a cleaning). Once the bearings are removed, they can be taken to a bearing house for identification and replacement. The cost of the bearings, usually under $15 each, is far less than the cost of a "rebuilt" torque tube.

When disassembling the torque tube to replace the bearings, the torque tube shaft can be pressed out either end of the torque tube. The shaft will come out pretty easily, as it's held by a very light press fit in the bearings, though this ease can vary depending on wear. Take a measurement of the offset from a bellhousing mating surface to the end of the drive shaft, to ensure the shaft is reassembled in about the same place. The bearings are held into the tube by metal carriers with splined rubber OD, again a press fit. Looking into the front of the torque tube, there is evidence of the splined rubber bearing carrier OD having been pressed from the front of the tube (as there are "rubber spline wipe" marks on the ID of the torque tube).

Using a long, small pipe will do the trick if it fits just on the on the step-down at the front of the shaft (the one which fits into the pilot bearing ID). This way there is a very secure location to press the shaft all the way through the rear of the tube, past the last bearing, without damaging the end of the shaft. If the shaft cannot be driven out with a rubber mallet, be sure to use a piece of wood or aluminum to prevent damage.

Again, take measurements of the locations of the bearing carriers to ensure correct reassembly. The bearings/carriers themselves can then be pressed through with a second, larger pipe which pushes on the larger diameter of each bearing carrier.

Once these are out, the bearings can be replaced with new, freshly-packed bearings. The bearings are then pushed back into the tube, and the shaft pressed back in, making sure to get the bearings and shaft in the same locations.