Drive Train

Torque Tube Rebuild

Torque Tube Rebuild

Smooth like silk; well maybe not silk, but like some smooth powerful thing :). Finally got my torque tube rebuilt and back in the car. Now this is how the car is supposed to be!! I can't say that I found rebuilding the tube to be the most pleasant task I've ever done on the car, but I suppose it wasn't the worst either. I found MSC MSC to be an easy to use source for the torque tube bearings, their P/N 45666898 is SKF # 60062ZJEM which seems to be a valid substitution for the bearings in the tube. The directions for disassembly at worked fine for me. I found that pulling the "harmonic balancer" out was just as easy as pulling one of the bearings, so I took it out too. Good thing since mine turned out to be damaged. In fact I wanted to get everything out of the tube so I could clean the insides better, especially once I thought about how I wanted to "pin" the bearings and balancers in place. The bearings are supported in the tube by rubber-edged metal carriers, and the balancer weight is also supported between a pair of rubber and metal holders. Others have described "pinning" the bearing carriers in place by drilling through the tube and into the carrier at several places around the circumference of each carrier, then tapping the holes and driving in bolts. I'm sure that this will hold the carriers, but I was concerned about the ability to remove the carriers later with the "burr" from the holes in the tube holding the carriers even with the bolts removed. I would expect that this burr would tear up the rubber edge of the carrier(s) upon future removal, not to mention that various metal shavings would be trapped inside the tube when the holes are drilled and tapped. Also, the bolts directly into the carrier would eliminate whatever vibration/noise isolation function the rubber edge may have provided. Finally direct pinning would eliminate the ability for the carrier to axially align itself with the drive shaft. What I decided to do was to drill three evenly spaced holes both forward and aft of each of the carrier positions and to stop the carriers from travelling in the shaft by putting rivets in these holes. The rivets project into the interior of the tube and form stops for the carriers. I left a couple of mm's of extra space between the fore and aft rings of rivets, to allow a little movement of the carrier. I drilled all of the holes when the tube was empty, and removed any burrs on the inside of the tube, and then cleaned it thoroughly. This solution preserves the function (if any) of the rubber surround, and allows the tube to be disassembled again cleanly in 20 more years :).

All very good, BUT when I actually got my tube apart I found that the bushing in the front bearing was worn out, the middle carrier was broken, and one of the mounts for my balancer was shot. I knew that my front bearing was out of place, but it turns out this bearing wasn't even contacting the shaft, due to the worn bushing. The middle carrier had the centre "pocket" that actually retains the bearing completely broken away from the outer rubber coated ring, so this one wasn't supporting the shaft either. The forward mount for the balancer had failed such that it allowed the cylindrical weight part of the balancer to contact the shaft!!, at least sometimes, based on the marks on the shaft. So, I really only had the rear bearing operational, and the balancer weight was dragging on the shaft. What a mess. At this point I was wishing I'd just popped for a rebuilt unit. But, a rebuilt unit would have had bearings that would probably just migrate out of place later on me anyway, so I'm happy to have done it myself after all. So, I needed a bushing, a carrier, and a balancer mount. One lister offered to make me a bushing (thanks Jerry!!), and another suggested that a carrier could be machined out of a urethane wheel (excellent idea Barry!!). This still left me without a balancer solution. I know that some have left the balancer out, but I read that it was designed to damp a vibration at 4200 rpm and I did have just such a vibration, before my DE spin when my vibration problems got much worse. It is my theory that the middle carrier somehow broke during that spin, though I really can't say why. What is for sure is that my vibration started immediately after the spin, and is now gone once the tube is fixed up. So, I needed parts. I called around the Toronto area and found a "good" used tube for C$400 which should either be able to provide parts. or be a better rebuild candidate than my tube. Kind of pricey, but still less than a rebuilt and no 2-way shipping. I kept looking. I then called Whaletail in Kitchener, and Randy there seemed to want to help. After a couple of days he came up with a somewhat "rough" tube for C$50 (~U$35)!! Now that's more like it. I zipped out to Kitchener and picked up the tube. It was basically in better shape than my own tube, and provided all of the parts I needed to complete my rebuild.

Also, a by the way, I was able to remove the torque tube from my 83 US 5 Speed without undoing the rear suspension at all. There is enough room to shift the tranny back and tilt the tube down far enough that it can be removed under the bell housing.

Eric Buckley
83S 5Spd. Red

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