Pinion angle . . .

[Bill Cleveland]

Ideally, the pinion angle should be about 3 degrees up, and the trans tail shaft about 3 degrees down, right? Well . . . because of the way my car is set up, it is just the opposite, with the pinion pointing down slightly, and the trans up slightly. Will this cause problems?

[Lee in KC]

Spank, my understanding is that the angle of the pinion/transmission relative to the ground is not the important factor, but rather the relative angles between the transmission output shaft and the pinion input shaft. The axis of each needs to be parallel but offset (to spin the bearings in the u-joints). So if your trans output shaft is, say 2* up, then your pinion input shaft needs to be 2* down. And they don't need to be dead-nuts on... plus or minus a few tenths of a degree is fine for the type of driving we do in our Ts.

(Disclaimer: this advice is worth exactly what you paid for it!)

[Orville Duncan]

One problem I see is every time you hit a bump or the springs flex for any reason such as more weight in the car your shaft angle will increase. Under normal conditions it would decrease when the rear-end comes up. With the angle increasing you could reach a point were the drive-line slips out of the transmission tail shaft, also you would exceed the three degree angle every time with every flex of the springs. With that said, could it work ? Maybe - just be aware there could be problems. Another thing is the reverse angles on the engine and tranny to their designed angle for optimal operation.

[Bill Cleveland]

Thanks, guys. Good advice! I'll have to live with it the way it is for a bit. Orville makes a good point re: rear axle movement. I don't believe there is enough travel for my yoke to slide out, but . . . hope my u-joints hold up!

[cecil misner]

A universal joint will operate very well if it is NEVER in a bind. Drivelines Northwest built my drive shaft and I took the car to their shop. They took off the shocks and installed a dummy drive shaft and jacked the rear end through it's maximum travel. The tech told me that the pinion yoke should point to the transmission tail shaft. If it does, the driveline will create proper angle for u joint operation. It is the angle of the DRIVE SHAFT that causes the needle bearings in the caps to rotate. It is relatively unimportant if the rear yoke is higher or lower than the transmission tail shaft.

[Bill Cleveland]

Thanks, Ceeeec! Good to know!