AL4 auto gearbox overfill, are seals ruined?

So after 30 hours it drained 3.3 litres, and after adding 3.8l new, 10min drive and level checking at 60degrees it drained 0.5 litres. So add an extra half litre to what comes out should work well for level checking and it'll drain the extra 0.5 if the level was originally correct. 🙂
 
My ZF4HP20 uses the same oil and had never been changed when I bought it (had it tested by a lab in Sydney). To help prevent it from developing the usual problems it was completely flushed and the water/oil heat exchanger was replaced with a more conventional air/oil trans cooler. The guy who did it knows his stuff and used mobil/esso LT71141. I will be using it from now on. Don't care how expensive it is, you don't change it that often and a new gearbox is almost impossible to find.
 
Stephen Murray said:
My ZF4HP20 uses the same oil and had never been changed when I bought it (had it tested by a lab in Sydney). To help prevent it from developing the usual problems it was completely flushed and the water/oil heat exchanger was replaced with a more conventional air/oil trans cooler. The guy who did it knows his stuff and used mobil/esso LT71141. I will be using it from now on. Don't care how expensive it is, you don't change it that often and a new gearbox is almost impossible to find.
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Well, its your money but the esso lt71141 just isn't a very good fluid. Its old tech mineral oil and the Penrite FS is a much much better option for longevity and performance.

If it was really that good, cars would still be using it. And Renault would have used it instead of the much better ELF synthetic.
 
Umm, LT71141 was original fluid specification for AL4 and 4HP20, so not a surprising choice - but as Haakon says, there are new synthetic alternatives.
 
How do they completely flush out what is in the torque? The flush would have to be part of the circuit supplying the torque and not just an entry/exit of the overall gearbox. I've read that a flush may not be as good an idea as it sounds because it can dislodge debris and move them into damaging locations within the gearbox.

Safer to do 3 ordinary fluid changes a month's driving apart you end with 90% new fluid. I say a month apart cause I've no idea how long it takes for the fluid in the torque to completely mix with the new fluid. It might be a day, a week or a few minutes driving but a month should be sure.
 
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I think there is some gizmo that attaches instead of the heat exchanger that catches the oil coming out of the box from the oil pump and feeds in fresh oil to the box at a similar flow rate until the oil coming out is freshish.

Cheers, Ken
 
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Where abouts is the breather tube in the al4?

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Kcar said:
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Hi Kcar. I know this is an old thread. I have the same exact problem with my AL4 P207 (2 L in excess and now leaking). Did you replace the seals, or just stopped after drained the excess?.
 
I overfilled about 10 years ago.
After a few weeks of driving like that, I drained it to roughly the right level.
Over the years since, I drained and refilled about 3 litres every 3 years and it's still going.
 
Clogzz said:
I overfilled about 10 years ago.
After a few weeks of driving like that, I drained it to roughly the right level.
Over the years since, I drained and refilled about 3 litres every 3 years and it's still going.
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Thanks Clogzz, that's a relief. It was overfilled just a couple of hours and 50km driving. Now is filled with 3lt. I'll drain to the right level with the 0,5L method the next time.
 
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