VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1912-1928 1928 growling noise

I have owned my "28" for 17 years and travel a couple of thousand miles each year. During that time I have replaced the bush at the head of the torque tube 3 times.I was driving it the other day and there is a growl from "down there" when I lift my foot at speed. I thought that it might be yet another bush gone but when I put my foot on the clutch the growl goes away.
Before I pull the gearbox can anyone suggest what it might be?
Thanks

Terry
Could it be clutch plate or throwout bearing issue? Transmission bearing? Did my 27 clutch this year.
Ken

If it also does it when sitting still but the engine slowing down from high speed and "clutch out" look at the front trans bearing or the bushings in the lower cluster gear. If you used regular modern gear oil in it, the sulfur in the oil may have ate the bushings and is letting the gears wobble and the teeth are going in and out from normal mesh, or if the main shaft bearing is worn it will let the constant mesh gear wobble on the counter shaft. You may be able to feel the vibration in the shifter lever if it is in the tranny itself. Just remember that straight cut gears will vibrate some normally and will be louder when out of the line they were used to running in all those years. If a bearing or bushing is out then the vibration will be worse and will change with load.

I fixed it! I took up the floorboards and went for a drive. It was obvious that the noise was coming from the gearbox, universal area.I reached down and held the torque tube and could feel that someting was touching. I then pulled up on the torque tube and the noise went away; not that there was much movement but it was enough. I relaxed on the torque tube and the noise came back.
I removed the universal and found that the tailshaft bush and rear gearbox bearings were fine but the universal joint was shot. A couple of the balls had 1/4 inch clearance on the pinion in places.Fortunately I had a spare with good balls so it is now all back together and running quietly.
Thanks for the comments; they all help to solve a problem.

Are you aware that the trunnions (balls) should only go in one way?

Trunnions,of course! Couldn't quite remember the word.Usually applies to my Triumph TR3 not my Chev. Anyway I do remember something about going in one way but what does that mean? Is there an inside face and an outside face? Further details appreciated.

Not to worry.I just ran a search in the later forum and there was the explanation.Thank you!

Cool, glad that you found the discussion. As you found out there is an inner face and an outer face.

Dog
A description of the inside vs the outside sure would help clear up which way they go in
Chris

trunnion ball bores are slightly radiusd on insideface to accommodate spigot diameter. But, how much sideways movement is acceptable?