Last week we had a customer from Miami that had run out of options. He'd had all of his tires balanced and even installed new, OEM u-joints in his Toyota Tundra's drive shaft. This still didn't cure the vibration he was experiencing in his truck at speeds of 60mph and over. After calling other shops and being told they couldn't balance the shaft, he finally called us. When he brought the shaft to us, we saw that it used the standard Toyota 46mm flanges at both ends to attach to the truck. At Proshaft, we maintain in-house machining capabilities for situations just like this where we might need to manufacture new adapters for our balancer in order to accommodate a customer's specific needs. Much like with other situations, we opted to make the adapters from aluminum in order to get the job done quickly. In the next week or so, we'll replicate these same adapters from steel so we'll have a more "permanent" set of adapters for the balancer.
Upon further inspection of the drive shaft, the universal joint replacement that the customer had done looked really good. All the joints moved freely and the constant velocity unit moved smoothly as well. The only thing left to do was go forward with the job to find out if the drive shaft did indeed show a vibration.
This is the set of adapters we machined to adapt our balancer to the Toyota Tundra's rear drive shaft. These will only be temporary since we'll replicate these from steel for a more durable set.
With the adapters ready to go, the rest of the drive shaft balancing procedure would be pretty straight forward. Since the Tundra has a two-piece rear drive shaft, we'd be detecting out of balance at three different locations simultaneously: the front of the drive shaft, the middle at the shaft's center support bearing, and the rear of the drive shaft.
This is front of the Tundra drive shaft attached to the balancer.
This is the Tundra's carrier bearing mounted in the drive shaft balancer. Note the vibration censor installed on the center bearing support column.
This is the rear attachment flange of the Tundra's drive shaft affixed to the balancer.
Here is the complete Toyota Tundra drive shaft attached to the balancer. We've got everything nice and level and we're ready to balance the shaft at this point.
With the drive shaft attached securely the balancer, we started the balancing process. Most times, if there is an issue with a component or damaged tubing, it will be immediately apparent while the shaft is rotating in the balancer. During calibration, everything looked good. Once calibration was complete, between 10 and 20 grams of out of balance was detected at each attachment point in the Tundra's drive shaft. This was most likely due to the components being reassembled out of phase with the original balance. Any time you disassemble a drive shaft for maintenance, it's important to mark the components prior to disassembly. This allows you to reassemble the drive shaft the same way that it was originally balanced and minimalizes the chances of vibration once reinstalled in the vehicle.
Here, we're giving the Toyota Tundra drive shaft a final spin in the balancer to ensure that the weights we've taped into place are removing the vibration. After this process, the weights will be tack welded into place.
With the balancing complete, we marked the front and rear sections of the drive shaft so that they could be reinstalled "in-phase" in the customer's Tundra. The balancing weights were tack welded into place and everything was painted and phasing arrows were added for timing. The customer informed us that this did indeed cure his vibration. Just a couple of days after completing this job, we got an order from another customer who wanted us to build a Japanese-spec Toyota Tundra front drive shaft. Stay tuned for our next article to see how we did it!