How To Use a Pinion Depth Gauge

Summary

In this video, the host demonstrates the best method for measuring and setting pinion depth when rebuilding a differential, specifically a 10-bolt GM. The tool used, from T&D Machine Products, is highlighted for its precision and ease of use, despite its high cost. The process includes using setup bearings, crush sleeves, and a dial indicator for accurate measurements, along with tips on shimming for proper pinion depth. The video emphasizes the importance of checking gear tooth patterns and recalibrating the tool to ensure accuracy throughout the setup process.

Takeaways

• 😀 The best and most accurate way to measure and set pinion depth in a differential rebuild involves using a specialized tool from T&D Machine Products.
• 😀 The T&D tool kit covers a wide range of differentials including Ford, GM, and Dana, making it a versatile option for pinion depth measurement.
• 😀 Proper setup involves using setup bearings, and it's crucial to ensure the setup bearing matches the final assembly bearings to avoid measurement errors.
• 😀 A setup crush sleeve is used during the initial setup phase, but for final assembly, a new crush sleeve should be used.
• 😀 When measuring pinion depth, ensure you use the correct shim size, and adjust it based on the measurement you achieve from the tool.
• 😀 The dial indicator used in the tool should be calibrated carefully, with the main goal being to measure the pinion depth accurately for proper gear alignment.
• 😀 Calibrating the dial indicator requires removing a calibration tube and adjusting the measurement so the needle points exactly to zero before use.
• 😀 To increase the pinion depth, decrease the shim size; to lower it, increase the shim size.
• 😀 It's critical to check the gear tooth pattern before finalizing the pinion bearing installation to ensure everything is aligned correctly.
• 😀 The tool can remain installed in the differential while making adjustments, but be sure to regularly recheck calibration to maintain measurement accuracy.

Q & A

What is the best and most accurate way to measure and set pinion depth in a differential rebuild, according to the video?

The best and most accurate way to measure and set pinion depth, as mentioned in the video, is by using a tool from T&D Machine Products. This tool provides precise measurements for differentials like Ford, GM, Dana, and others.

What is the significance of using the correct setup bearing and bearing races during pinion depth measurement?

Using the correct setup bearing and bearing races is crucial because mismatched bearings or races can result in inaccurate measurements, leading to improper pinion depth and potentially affecting the overall performance of the differential.

Why is it recommended to use a new crush sleeve for final assembly?

A new crush sleeve should be used for final assembly to ensure proper pinion bearing preload and to maintain correct pinion depth. An old crush sleeve may not provide the necessary clamping force, leading to an inaccurate setup.

What role does the setup shim play in the pinion depth setup?

The setup shim, which is measured for its thickness, is used to adjust the pinion depth. The video suggests starting with a shim thickness of around 40 thousandths of an inch for initial measurements.

How is the dial indicator used in the pinion depth measurement process?

The dial indicator is used to measure the pinion depth by contacting a magnet attached to the pinion. The tool measures the depth by reading the highest point of the needle as the tool is rocked back and forth.

What should you do if the center shaft of the measurement tool cannot spin freely?

If the center shaft cannot spin freely, it likely means the tool is misaligned. You should loosen the parts, reposition them to allow free movement, and then torque the caps down to 25 foot-pounds to ensure proper alignment.

Why is it important to calibrate the measurement tool before taking readings?

Calibrating the tool ensures that the measurements are accurate. By setting the tool to a known standard (such as 3.375 inches), you eliminate errors in measurement and can achieve precise pinion depth settings.

What does it mean when the final pinion depth measurement is slightly off from the spec, and how is it adjusted?

If the final measurement is slightly off from the spec (in this case, by 0.011 inches), adjustments can be made by changing the shim size. A smaller shim stack increases the pinion depth, while a larger shim stack decreases it.

Why is it suggested to check the gear tooth pattern after setting pinion depth?

Checking the gear tooth pattern after setting pinion depth ensures that the gears mesh correctly, indicating that the pinion depth and backlash are set properly. This step helps prevent premature wear or failure.

What should you do if you're using the tool repeatedly for different setups?

If you're using the tool for multiple setups, it's recommended to leave the tool in place in the differential while making adjustments. Be careful when working around it and periodically recheck the calibration to ensure accuracy.