Torque Tube Donut

[David12345]

1973 GT .. There is about 1/2 inch play at the torque tube. OGTS says it's the donut. So, I've been reading the manual (owm727), searching this site, looking at the tech diagrams, and I'm still confused. It seems as if there's plenty of info, but never a diagram to tie the info to the parts .. and sometimes parts have several names .. such as donut, center support damping ring, etc. The manual has a nice pic, but only has numbers with no reference to anything. And the tech diagram on this site looks the same, but says it's for up to 1972. And several of the treads go into doing more than I hope to .. never know. Would appreciate info as to how far I have to go and where to see a break down with parts listed .. panhard rod? rear dampers? anti-roll bar? I know it'll be easier the second time!
David

[traytodd]

Gil at OGTS has drawings for all of the parts you mention. The panhard rod is the diagonal rod behind the differential. Your car may or may not have a rear swaybar as these were not standard equipment on US GTs. It is a "U" shaped bar in front of the rear end. It arms attach to the rear axle and the base of the "U" attaches to the body. The torque tube is the tube that encloses the input shaft to the differential. The drive shaft is the short shaft between the transmission and the input shaft and has universal joints at each end. The torque tube donut or damping ring is at the front end of the torque tube and supports the central bearing. The donut is probably deteriorated if it is original. You will hear a clunk when accelerating around left hand corners if it is bad. There are also 2 threaded rubber support bushings and a rubber bomper on top of the torque tube support bracket. If you have a shop manual, there should be an exploded view of the rearend assembly.

I hope this helps.

Terry

[jeff denton]

Get OGTS's excellent parts catalog. And get their excellent replacement donut and shock mounts, all in a better, harder material. With these parts come instructions and tips.
You can't go wrong with OGTS. Trust me!
Gil will recommend you change the pinion seal while you have all this apart. Listen to him! He's the greatest.

[David12345]

As I learn the parts, I can follow the instructions. I did overlook the OGTS book, but, even with the great pics they show, (I think) part no 7006 is the donut but they do not define what it is in the book .. they left that one out.
And what is the purpose of the panhard and the torque tube? I've seen a lot of drive shafts, no torque tubes.
Thanks!
David

[GTJIM]

Lots of older cars had torque tubes - Ford V8s from 1932-48 and similar dated Chevys for instance.

The "torque" tube is there to help locate the diff and to allow up-and-down movement. It also controls the "torque reaction" as the pinion tries to climb the crownwheel inside the diff as the car accelerates.

The Panhard Rod is there to locate the diff from side to side and transfer the cornering forces from the diff to the car body.

The 'doughnut' is there to drive Opel Owners mad! I guess it is there to allow a bit of flexibility in to the rigid torque tube/panhard rod location set-up and isolate the diff from the body. This minimises the transfer of road noise up from the wheels.

The reason for it is that Opel just had to be a bit different -If all you guys had been content to be part of the Magnificent "British" Empire we would all call these bits and pieces by the same name!