ZF4HP22 harsh shifts!!

[pundit]

Okay so I serviced the trans at the weekend, changed the filter and about 5 litres worth of Penrite Dexron III (http://www.penrite.com.au/pispdf/ATFDX3.pdf) & also poured in some Nulon trans additive (http://www.nulon.com.au/prod_G60_auto_transmission_treatment.htm).
Well afterwards the ZF shifted as smooth as silk.... for only two days!... now is no better than it was. So something helped... for a while!! :(

[BigKriss]

oh well. how was the old fluid looking, was it bubbly, when you drained it?

[Alexlind123]

Now im scared...

[Kalevera]

Pundit, did you drop the pan? I would've left the additives out of the equation. Is the new stuff burnt?

best, whit

[pundit]

Pundit, did you drop the pan? I would've left the additives out of the equation. Is the new stuff burnt?

best, whit
I dropped the pan after I drained the fluid to change the filter. I previously changed the fluid about 15,000kms ago (under 10,000 miles). The fluid was still quite clean and definately not burnt. There was very little in the way of metallics stuck to the magnets. The fluid is currently very clean. The shifts are not always harsh but after servicing the trans the other day they were very consistantly smooth for a couple of days. My thoughts are the additive probably helped but it's effect wore off rather quickly.

After speaking to a few BMW people about this they all seem to think it's just quite normal for a ZF4HP22 to have random harsh shifts.

[Blitzkrieg Bob]

But I have changed to fliud it seemed to smooth out, with only a hard shift once in awhile when it downs shifts in heavy traffic or when I stomp it to pass a slug on the road.