Thread: How much play is needed if any in drive shaft?

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I was wanting to know if you guys could tell me how much play is needed in the front to back movement of the drive shaft. If you loosen up the u-joints and slid your drive shaft forward how much should it move?

If you are talking about slip yoke travel, the answer is "depends upon the vehicle." The slip yoke must never bottom out (go all the way in) during the suspension travel nor can the slip yoke pull off of the spline enough to bind.

For our Jeep, we have 8 inches total of slip yoke travel because we have 14 inches of suspension travel. For a car with limited suspension travel, the slip yoke travel is much less...perhaps as low as a couple of inches. If you jack your vehicle up by the rear axle (compressing the suspension) you can look to see (after installing jack stands under the axle) how far you are from the yoke being all the way in.

Then, you can jack up the vehicle by the body and let the suspension droop. Dont forget to use the jack stands. The yoke should still have at least an inch or so of engagement. If the yoke comes out when you go over a big rise (unloading the suspension), you are in for a fun time with a driveshaft flopping around under the car.

Also, when you have the suspension at its up and down limits, turn the driveshaft to make sure you arent binding the U Joints because of excessive angle.

If you've got about 5"-7" of space between the axle housing and the rubber bump stopper, then your driveshaft will slip in and out about an inch. That's for a one piece driveshaft in a car. If you've got a 2 piece driveshaft in a lifted up truck, you've got some serious travel. Use Robot's method to measure it.