Checking gearbox oil

Part 1. Preparation and safety

Objective

• Check the lubricant level of a transaxle and final drive.

Personal safety

Whenever you perform a task in the workshop you must use personal protective clothing and equipment that is appropriate for the task and which conforms to your local safety regulations and policies. Among other items, this may include:

• Work clothing - such as coveralls and steel-capped footwear
• Eye protection - such as safety glasses and face masks
• Ear protection - such as earmuffs and earplugs
• Hand protection - such as rubber gloves and barrier cream
• Respiratory equipment - such as face masks and valved respirators

If you are not certain what is appropriate or required, ask your supervisor.

Safety check

• Do not put your finger into the filler plug opening to check the fluid level whenever the transmission is rotating.
• If the vehicle has been driven just prior to checking the fluid level, the fluid could be very hot. When you remove the filler plug, the hot fluid may run out. Be careful not to burn yourself.
• Make sure that you understand and observe all legislative and personal safety procedures when carrying out the following tasks. If you are unsure of what these are, ask your supervisor.

Points to note

• If the vehicle is not level when taking a reading, you could get an inaccurate result.
• Selecting and using the correct type and grade of lubricant is critical. The wrong lubricant can lead to premature failure of the internal components.

• A correct fluid level is critical to effective and efficient operation. If the level is too high, the fluid will churn and aerate, causing air bubbles that can trap heat and allow the fluid to run hotter. This can lead to early failure of bearings or gears.
• A low fluid level can cause as much of a problem as a high level. Air can enter the system, and heat generation can result in the burning of vital internal components.

Part 2: Step-by-step instruction

1. Prepare to check level
   Raise the vehicle on a hoist and make sure it is level. Find the filler plug, referring to the shop manual if necessary. Clean the area around the filler plug to keep dirt out of the engine. As a precaution, place a drain pan under the plug to catch any fluid that may leak out. Remove the filler plug with the correct wrench to prevent damage to the plug, and check the level at the bottom of the filler plug opening. If fluid begins to leak slowly, then the reservoir is full. Immediately replace the plug. If fluid runs out freely, let it drain into the drain pan until it seeks its own level, which is just at the bottom of the filler plug opening. If the lubricant level is below the level of the filler plug, bend a short length of metal wire and insert it into the fill hole. Pull the wire out and note the lubricant level. If the level is down, you will need to add fluid of the correct lubricant type and grade, to bring it up to the recommended level.
2. Replace the filler plug
   Check the plug for damage to the thread, and sealing gasket if it exists. Install a new gasket. Replace the filler plug and tighten it with the correct wrench to the manufacturer’s recommended tension.