Bad Spider Gear Symptoms for Equipment – What Should You Know?

Differentials are used in heavy equipment and agricultural equipment in all cases. They are special units that allow two joined axles to rotate at a different speed. For example, the differential is a part of pretty much any transmission because it allows two axles in a vehicle to rotate at a different speed when the vehicle is turning. Otherwise, one wheel would always slip while the other one would rotate slowly.

So, differentials are used in all equipment and one of the important parts of any differential is the spider gear. This is a special gear that rotates around the differential case and allows the differential to do its job. Today, we'll tell you everything we know about the symptoms of a bad spider gear and also some ways to repair it or prevent problems.

Here's what exactly we'll be talking about:

• What are the symptoms of the bad spider gear in your transfer case?
• Why can the spider gear go bad in your equipment?
• What should you do to get rid of the problem with the spider gear?
• How can you avoid problems and prolong the life of the spider gear?

Let's get started!

Symptoms of the bad spider gear in the differential

So, we are a blog about heavy equipment and industrial machines. But before we start, we want to let you know that transfer cases and differentials are more or less the same in all equipment. So what we tell you today is true for trucks, semi trucks, RVs, SUVs, and even passenger cars that have these units in their construction.

Essentially, the differential is the set of four (or more, or less) gears that are connected with each other. Once the transfer case needs to do the job, the spider gear comes into action. It means that when it works (and this is pretty much all the time when you use your equipment), the spider gear comes in contact with other metal gears in the system.

Here are the most common symptoms of the spider gear going bad:

• grinding noises from the differential - this usually means that the spider gear lacks one of two teeth and is now being destroyed even further;
• rattling noise from the differential - this means that the gear may have lost its position because of bad mounting and now rattles destroying the whole unit;
• weird sounds when turning or using the differential in any other process - this is the time when the spider gear comes into action and may produce bad sounds signaling about its death;
• stuck differential - in this case, the spider gear may have completely fallen out of been destroyed which could cause the blockage of the differential work;
• metal shavings in the fluid - this is the relatively simple way to check whether your differential is affected badly - to see if there are metal shavings in the fluid;
• other symptoms that come up when you turn the machine or do any other job that involves the differential.

Actually, all kinds of bad sounds that come from the differential may mean that there is something wrong with the spider gear. Locating the issue is not that easy because when you are doing the job in the cabin, it's quite hard to understand that the sound is caused by the differential. But when the machine is standing still, the spider gear is not involved, so everything may seem to be fine.

In many cases, good soundproofing in modern equipment is one of the reasons why operators don't hear any sounds when the spider gear just starts sending bad signals about its soon death. But when you can hear these sounds, it's too late to try and prevent the disaster. In most cases, you will have to repair it.

For your consideration, spider gears are usually called satellite gears or side gears. This may help you investigate the prices for needed parts.

Why can your spider gear have gone bad?

The reasons for this problem are pretty natural. The differential should get lubricated when your equipment or truck are working. For proper lubrication, the machine should get enough oil or fluid of high quality. Bad-quality materials or low levels are usually the most common reasons why your differential may have failed.

But of course, there can also be other reasons for this. We've decided to outline the possible causes of the problem with your spider gears:

1. Low oil level. This problem can kill anything in the transmission system. The fluid should always be above the minimum level, otherwise, the gears will grind over each other and eventually fail.
2. Poor oil quality. Every kind of mechanism has certain recommendations on the type of oil and its quality. Never experiment with these factors and always buy the proper fluid that's recommended by the manufacturer of the unit.
3. Old fluid. Every fluid has a lifespan that may be counted in years and engine hours. You should know when to change the fluid, otherwise, the old oil will just lose its qualities and destroy the differential.
4. Lack of attention. Very often, transmissions and transfer cases message operators about upcoming problems by producing weird sounds or even by turning on some error lights on the dashboard. Neglecting these symptoms may lead to a total disaster.
5. Overloading. Every mechanism has its capacities and understanding them is the best way to prolong the life of the machine. If you tow or haul more than the equipment is meant to, you will eventually have to pay for an expensive repair.
6. Poor quality of parts. If your differential has already been repaired, the mechanic may have installed poor-quality parts to save up some money. This will lead to a shorter lifespan of the mechanism.

These are just the most common reasons why the differential may have gone bad. There are dozens of other things that should be considered. Any physical damage has to be seen as the most obvious way to kill the differential. Also, fluid leaks should be taken into consideration.

Once you understand that the spider gear is broken, you should immediately make the right decisions. The worst mistake you could make is to continue using your equipment or truck paying no attention to what's happening with the differential. This way, you'll guarantee additional costs for repair.

How can you prevent problems with the spider gear?

Unfortunately, sometimes the spider gear will go bad just because it's old and has seen enough of this life. It may get broken because of natural wear and tear. But usually, it happens not earlier than after 15-18 years of intensive use. In this case, you can't prevent the disaster.

But you can still prevent some other bad factors that usually kill the differential. Here are the most obvious recommendations you should consider:

• always change the fluid as soon as it's needed, also make it even more often when the equipment is old and worn out;
• prevent overheating - there is no active cooling, so you may prevent overheating just by considering all manufacturer's recommendations;
• avoid overloading your machine - this is the most precious thing because overloading inevitably leads to worse wear and tear;
• have the unit diagnosed once you hear some weird sounds from it - this will help you prevent big problems and just repair the differential without replacing it;
• stop using your machine once you understand something is wrong with the spider gear, otherwise, you will tear it apart and will have to replace it;
• be especially careful with your decisions if your equipment is still under warranty, immediately contact the dealership and get all the needed instructions.

Yes, in most cases, you will not be able to avoid problems or prevent the differential from being broken. But at least, you will minimize possible consequences and will obviously spend less money, in the end, to get your equipment back on track.

Of course, the quality of repair should be high. If the specialist tells you that the whole differential needs replacement, don't try to make him replace the spider gear only. This will lead to new problems and the equipment will never be reliable again.

Final words

So, the spider gear is an important part of the differential in any machine. And it can fail if overloaded, overheated, just too old, etc. We've described here some of the most common symptoms of bad spider gear so that you could easily recognize the problem and immediately ask for professional help. In most cases, there are no DIY solutions because for replacing or even diagnosing the spider gear, you will need to take apart the differential which is not easy at all.

To prevent even worse problems, never use your equipment with broken spider gear. This may lead to more damage and eventually, it will make you spend more money on the repair. There is no need to try and diagnose the problem by yourself unless you have perfect skills as a mechanic.