What causes differential backlash?

The pinion gear is supported by two bearings, whose pre-loads are established by a crushable spacer between them. When a differential is set up this spacer is crushed by tightening the pinion nut; if the spacer is crushed too much, you get excessive backlash.

What happens with too much backlash?

Ring and pinion backlash. As the gears operate, they produce friction and heat. This makes the gears expand, reducing the clearance between the meshing teeth of the gears. However, too much ring and pinion backlash can cause gear noise (whirring, roaring, or clunking).

What happens when backlash is loose?

What happens if backlash is too tight or too loose: Too tight will generate excessive heat and quickly wear out the gear. If it is too loose, this will allow the gears to beat on each other, and you will eventually fracture or break teeth off the gears.

How do you check gear backlash?

Turn the adjustment knob on the side of the dial indicator gauge until the gauge needle points to the “0” setting. Rock the ring gear back and forth with your hand while monitoring the gauge needle. The distance indicated on the gauge is the gear backlash.

How do you diagnose differential problems?

Here are the most common bad differential symptoms to look out for:

  1. Your vehicle is quickly going through oil.
  2. Difficulty steering.
  3. A loud front differential noise, such as the grinding of gears, clunking, or a “howling” sound.
  4. Rear differential noises.
  5. Extensive and inexplicable wear and tear on your tires.

Why is backlash bad?

Backlash creates an issue in positioning when an axis changes direction. The slack in the threads/gears cause measureable error in axis positioning. The MachMotion software can compensate a small amount for this error and better track the true position.

What are the harmful effects of backlash?

At low power outputs, backlash results in inaccurate calculation from the small errors introduced at each change of direction; at large power outputs backlash sends shocks through the whole system and can damage teeth and other components.

How do you fix backlash?

The simplest and most common way to reduce backlash in a pair of gears is to shorten the distance between their centers. This moves the gears into a tighter mesh with low or even zero clearance between teeth. It eliminates the effect of variations in center distance, tooth dimensions, and bearing eccentricities.

What is meant by backlash error?

Backlash error is the error that occurs while we are changing the direction of gears. It can be avoided by turning the gear slowly in the same direction. Backlash error can also be defined as the clearance or lost motion in a mechanism caused by gaps between the parts of the gear.

What are the symptoms of a bad front differential?

There are a few noticeable signs that will present themselves if your front and/or rear differentials start to wear out or get damaged. Here are the most common symptoms that you can expect to happen if your differential goes bad. Whining noises are one of the most common and noticeable symptoms of a bad differential.

How to repair your BMW diff noise ( instruction book )?

Generally the only way is to take the differential out of your car and replace the worn out bearings with new bearings. Sometimes people use an additive to the differential oil that makes the noise quieter. All this does is delay the day the real work needs to be done. You cannot solve your real noise problem by using additives in the oil.

Why does my rear differential make a whirling noise?

If your gears are newly installed and still create a howling noise, double-check its preload and make sure that the teeth are properly aligned. Rumbling and whirring noises at speed over 20 mph, moreover, can be the result of worn carrier bearings. For vehicles with C-clip axles, the rear differential noise may change at different turns.

Why does MY BMW 135i differential whine?

This video shows a classic example of BMW 1 series diff noise, whining on and off acceleration. It would be wise to replace the diff bearings now before it fails completely. BMW 135i Differential Hum/Whine from BMW Ihaveone on Vimeo. What’s inside your “How i rebuilt my BMW differential” book with over 110 pictures and easy to follow instructions ?