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ATF Drained - Need Advice

Heimkehr

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The car stood for 2 weeks without starting the engine.
I removed the Fill Plug of the ZF 850RE transmission and drained about 3 liter ATF through it.
Then removed the pan and drained another 3 liter ATF , total 6 liters.
As far as I know, when changing the oil, you only need only 4 liters.
Is This Normal?
I'll bypass the existing posts and get straight to the point:
Changing the transmission fluid, and/or checking the fluid level on the ZF8 via the Fill port, is a prescriptive process. It needs to be done correctly, via a temperature-based process outlined in this excellent DIY thread. Only when the proper steps are followed should the transmission be disturbed in any manner.

The total system capacity of the 850RE is approx. 9 quarts, of which only 5.5 quarts will drain out when the pan is removed (again, following the correct steps outlined in the linked thread.) This is why the DIYer will want to drain and refill the fluid, and change the filter, at least twice -- three times is best -- so as to maximize removal of the old fluid. By way of example, I drive 1K miles in between each fluid & filter change.
 

roaniecowpony

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My perspective on the process is somewhat less than strict adherence to the entire process. I believe the published step by step process is intended for the dealership or shop, where the fill process has only one opportunity by the shop to fill it, pat it on the ass and send it down the road, and not have a low fluid condition.

We all know how OCD this crowd is. There is no doubt in my mind that 90% of you guys out there will check it again after driving it for a few days. It's just our nature. The temperature range will be followed by you as much as possible. But what if you miss it? Sell the jeep? Get a new transmissioni? I think not. You'll fill it, drive it, start all over with the warm up and check procedure, once it cools down. There's always the potential for air to be in the system and eventually bleed out of lines and coolers. So, look at it a bit more pragmatically. The transmission will function perfectly fine with a small bit of low fluid condition. There is tolerance in fluid level. How much? I dunno, but some. Clearly, the roads we drive are not level, neither laterally nor longitudinally. So, we know it has a lot of tolerance to fluid level. So, I'm not going to sweat it if I take too long during the fill process and the temperature exceeds the upper limit. I'll just fill to the port, drive it and check it when I can get the temperature within range. All I'm saying is; you're not going to trash your transmission if you miss the check temperature or put it in reverse before drive, or visa versa.
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