whats the difference?

[chrissbee77]

Okay so i just read the previous post about changing tranny fluid. My question is what is the difference between a pan drop (what does that include) and a tranny flush (what does that include) if my car has 166,000 miles and has never undergone any one of these services which one should i have the shop do.

[jessep28]

Transmission fluid, like oil, needs to be replaced every so often since it will normally break down from doing its job of lubricating the transmission components.

With a pan drop, the pan that sits under your transmission is removed, fluid drained, filter changed, pan reinstalled and clean transmission fluid added. When a flush is done, a machine is hooked up to the transmission’s cooling lines and the fluid is replaced while the vehicle runs.

For older transmissions, it’s generally recommended that just a pan drop and filter screen change is done. This is because flushes, especially at high mileage, have been known to exacerbate transmission issues and many times lead to component failure and a subsequent rebuild.

The only disadvantage in the pan drop is that it doesn’t remove 100% of the old fluid since some still stays in the torque converter.

Hopefully others can help me and chime in since I am not a mechanic and just speaking from reading this board in the past.

[tblake]

Sounds good to me.

[richtazz]

You hit it right on the head Jessep28.

I would strongly suggest against doing a fluid exchange/flush at your mileage. As I've stated about a million times, if you wait until the trans fluid needs to be flushed, your too late and doing so won't help. Doing a pan drop/filter change replaces about 75% (or more) of the fluid and is more than sufficient during regular maintenance. Trans flushes are a way for shops to make money without having to drop the pan. Any shop whose machine uses the transmission's pump to circulate fluid and claim their service "back flushes" the filter are lying through their teeth! Ask yourself, how can it "back flush" when it's drawing the fluid through the filter????