If you have a front-wheel-drive vehicle, you won’t need to disconnect the drive, but if you have a rear-wheel or 4 wheels drive, you will need to disconnect the drive to protect it.
Consider that putting your drive into neutral and releasing the brakes might release the vehicle’s mobility, but the drive is still connected to the shaft and this will lead to overheating when towing. That is the reason why drive shafts are disconnected by professional towers.
One other consideration is removing the drive shaft completely, and in this instance, you will need to seal the transmission to prevent loss of fluid as well as possible damage.
A Brief History
After 20 years of working as a class 8, heavy-duty duty truck tower I can state a few basics before I get into the actual how to do it.
- Rule №1 Always hook the care from the rear.
- Rule №2 If you can’t hook it from the rear, remove the driveshaft before towing from the front.
- Rule №3 If you can’t hook from the rear, or remove the driveshaft, then remove the axle (or axles). Once the axles are removed you can hook from the front.
- Rule №4 Only tow rear hooked vehicles without uncoupling the drive shaft for very short distances since it always leads to damage.
Disconnecting the Drive Shaft
- Step 1: Marking the Driveshaft. Before you begin to disconnect the driveshaft, you need to mark it. This helps when you return it to the original position it as on in relation to the differential. This mitigates driveline vibration risk after you reconnect it.
- Step 2: Remove the Bolts. As in most things mechanical, there are bolts to unscrew. Since these are driveshaft bolts they will be extremely tight, so make sure you have an exact tool to assure you don’t strip the bolts while trying to unscrew them. There are different bolt sizes, so be prepared. You will find 12 point heads that require a 13mm socket wrench to unscrew. These bolts are designed to lock on tight, so they don’t come loose during the driveshafts operation.
- Step 3: Removing the Driveshaft Flange. Take a plastic hammer as to avoid damage and gently tap the rear yoke to shock the driveshaft loose from the differential flange. Take heed that the back half of the driveshaft is now free, which means you need to hold onto it. Another item to remember is that some vehicles come with center support, you will need to undo this. You undo the center support by unscrewing the two mounting bolts. For old vehicles, have some electrical tape handy, you will need to wrap this around the u-cup joints to make sure they don’t jog loose and let the needle bearings fall.
- Step 4: Disconnect the Driveshaft. Make sure you place a basin under the driveshaft to transmission joint. To totally disengage the driveshaft, you need to use both hands and slide the driveshaft gently away from the transmission case or transmission. You will notice some fluid leaks out, that’s why you placed the basin.
- Step 5: Check the U joints. After you have completed your tow, check the u-joints to see if they provide smooth motion, you do this by holding onto the yoke and moving it around. If there are any rough areas in the movement, you need to replace the u-joints.
- Step 6: Reinstalling the Driveshaft. It’s time to reconnect the driveshaft, after all, disconnecting it was one job, now it’s time to reconnect. Apply some grease to the yoke, then gently reinsert the driveshaft yoke in order not to damage the seal. The rear seal is usually found together with the dust boot in the transmission or transfer case rear housing seal. Guide the yoke into its place to the output shaft.
- Step 7: Rebolting the Flange Bolts. To assure you don’t cross-thread, pull the driveshaft back into place after you have installed the front yoke. Check the alignment marking you made and install all the bolts. Now tighten the bolts using a torque wrench and set it to 55-65 foot-pounds. I suggest filling up the transmission case with fluid since you most probably lost some while disconnecting.