Ideally a transmission in cruise mode has very little wear at all. Mainly the planetery gearsets as the clutchpacks and bands are, or should be locked up completely by hydraulic pressure holding them in gear. Transmission friction materials wear during shifting. Suprisingly a soft shift wears more than a firm shift as slow engagement of clutches/bands smooths out a shift but allows more slip and therefore more wear of the friction materials in doing so. A firm quick shift is preferred. obviously this is only up to a point. Banging hard, harsh shifts are hard on parts from shock loads and hard on friction materials from the sudden engagement. It should be obvious that a maladjusted transmission will wear faster if allowed to flare, slip, etc. The other great killer of transmissions is heat. Everyone knows about those little o-rings on the oil filter housing cover rod that get all brittle and no longer seal? Well imagine that X1000 with all the seals in a 20yrd old transmission. This is what products like Trans-X address besides varnish and crud removal. They contain seal-swelling and softening agents to attempt to restore flexibility and therefore sealing ability to these hardened old seals. A vehicle that has been used to tow, carry heavy loads or drive in heavy traffic extensively has more of a chance of having heat damage. The transmission fluid is cooled by passing through the radiator. In most cases this is adequate. However when towing, heavy stop-n-go, etc. fluid can easily exceed +260*. This kills the lubricating qualities of the oil and cooks the life out of the seals. ATF is supposed to have some seal conditioning agents in it so changing is regularly will help keep seals alive. ATF will also break down just like motor oil at high temps depositing sludge and varnish in the transmission that causes other problems. This is where synthetics offer an advantage. They don't break down at high temps, so no sludge/varnish. This also means they retain their lubricating qualities longer. RT

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When all else fails, vote from the rooftops!
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