What are the effects of not changing transmission fluid for a long time?

[RyanFitz]

If the transmission fluid is not changed for a long time, it will accelerate the wear of the transmission and may even cause damage to the transmission's shift control mechanism. For manual transmissions, prolonged failure to change the transmission fluid can lead to difficulty in shifting. Automatic transmissions have shift control mechanisms that require transmission fluid to function properly. When changing the transmission fluid, it is essential to go to a professional service center and use specialized equipment. There are two methods for changing transmission fluid: the gravity drain method and the machine flush method. If the transmission fluid is not changed for an extended period, it will become increasingly viscous, impairing heat dissipation and causing excessive temperatures. Over time, this will affect the transmission's lifespan.

[LeAmara]

As a veteran driver with over 20 years of experience, I've learned many maintenance lessons the hard way. The most severe consequence of not changing transmission oil for extended periods is insufficient lubrication, which accelerates wear on internal gears and bearings, causing abnormal noises or jerky shifting. When the oil deteriorates and thickens, its cooling efficiency drops, making the transmission prone to overheating—sometimes even triggering protective shutdowns. Once I procrastinated until 60,000 km to change the oil, resulting in loud noises, 10% increased fuel consumption, and ultimately thousands in parts repairs. Long-term neglect also allows sludge buildup that clogs oil passages, reducing transmission efficiency and potentially causing premature failure. Regularly check the oil's color and smell—changing every 40,000 km or two years saves money and ensures safety.

[DeTalia]

As a car enthusiast born in the 90s, this is the most frequently discussed topic when chatting about maintenance with friends. If you don't change transmission oil for a long time, dirt accumulates in the oil, lubrication deteriorates, gear wear accelerates, and shifting feels noticeably worse—almost like the car gets stuck. In severe cases, an overheated transmission can stall the vehicle, requiring towing for repairs. My buddy's car went three years without an oil change and ended up with over 8,000 RMB in repair costs. Deteriorating oil quality also affects fuel efficiency, accelerates vehicle aging, and significantly degrades the driving experience. I recommend developing a habit: check oil levels every 40,000 km or as per the manual—don't wait for problems to regret it. Simply put, changing oil extends your car's lifespan, saves hassle, and saves money.

[EloiseAnn]

From a cost-saving perspective, I'm always a penny-pinching office worker. Skipping transmission fluid changes saves a few hundred bucks short-term, but accelerates component wear, potentially leading to transmission repairs exceeding $5,000. I've learned the hard way: dirty fluid caused rough shifting and a 15% fuel consumption increase, costing extra monthly. Worse, my used car value plummeted, losing thousands at resale. Aged fluid also risks leaks or thinning, reducing drivetrain efficiency and compromising commuting performance. Proper maintenance with $100 fluid changes proves far cheaper than repair bills—a smart investment.