Doughnut installation (overcompressed?)

[Angus]

After seeing someones driveshaft bouncing down the back straight during my last race, I'm replacing the doughnuts and adding do-nut savers.

The new doughnuts appear to be "over compressed" by the metal band, the doughnut bolt circle is smaller than half shaft and output flange bolt circle. Is this common?

I'm almost tempted to cut the band and put on a metal hose clamp, but wanted to ask you guys first.

I've also got a bent "ear" on the right drive shaft, looks like this car had a doughnut failure in the past. Any suggestions on repair or should I replace the drive shaft.

Thanks!

Angus

[Jerry Kehoe]

The metal band is only there to help you assemble it to the driveshaft. If things don't line easily then go ahead and use a hose clamp to do the same. Make sure the doughnuts are aligned in rest and use spacers if needed to align them. The centering ball is the easiest way to prevent breakage as well as keep the halfshaft from flailing about. Just make sure you adjust them so they won't bind as well as make sure they are captured by the socket. All of the F2 cars in that era had them especially Brabhams. All you have to do is keep an eye on them for separation cracks (on the doughnuts) and if you find them then replace the part. When maintained properly they will last for several seasons.

[Jonathan Hirst]

I don't run a car with donuts anymore but I used to connect 3 hose clamps together and draw the donut down slowly using a 1/4 drive Rachet. The slots on the clamp bands can make a mess of the rubber corners if you aren't careful but lined clamps are more common now which might help if you are concerned.

The original band was too tight to slide it over the output shaft studs so carefully cut it off and go with the clamps. Compressing down to the correct pitch circle will make life much easier on you and the threads.

Those hose clamps lived in the toolbox for years. . Then I got a car with CVs.

Good luck
Jonathan

[Big_Texan]

Angus,

I have had good success with a 9" bar clamp plus a v-block. If you can find one with deep jaws, you can span from one point on the doughnut to the other, and use the v-block to get the clamp jaw sitting snug on threaded adjuster end. This lets you squeeze the doughnut to put in one bolt at a time, which is all I ever have been able to do anyway.

The whole process requires patience, but it will become easier and faster over time. Worst case I can help you in person if you get stuck.

Nathan