ZF4HP22 auto

[mark_i]

i use the auto 325i for smoking around in and to be honest is pretty good for Sydney city traffic.

Last week, the tranny gives a moderate thump going from 3->4 and the lock-up clutch in 4th stopped working.
Today i drained the ATF, dropped the pan and strainer, cleaned it all carefully with lint free cloths and refilled with 4 litres of Dextron III.

still getting the thump shifting to 4 and still no lock-up.

Any thoughts...or a slushie from the wreckers?

[Topblag]

wreckers.

You'll pick up a 325 auto box over here for £50 - how much are they in Oz ?

[mark_i]

not sure... $100... pounds 60
the condition of the torque converter is a factor to consder

[Andyboy]

The lock up clutch has failed. I wou;dn't fret, just keep driving it as it is. If it's a non switchable type with a kickdown cable, try disconnecting or slackening it. An overtight cable can cause this sort of thing.

[mark_i]

thanks mr Everett... its a non EH, so i'll check the kickdown cable.

out of interest, what causes the tranny to thump into 4th

[Simon13]

isn't that the torque converter locking up?

[mark_i]

no Si, when the TC was working and locks, the revs drop another 300rpm at 50 mph when in 4th.

what i got is a definite clunk shifting from 3 to 4.

i was hoping that after backwashing the strainer and cleaning the furry magnets would have had an effect.

[mark_i]

disconnected kickdown cable and... no luck.

Pity. even as an auto it pulls like a train with a mild speedtouch chip

[mark_i]

hmmmm... after 250 miles since replacing the ATF, lock up clutch is working again

[TPS]

I've got a 325i with a Switchable auto, it changes gear at 53mph, I think that means the torque Converter is working.

[B7]

hmmmm... after 250 miles since replacing the ATF, lock up clutch is working again

Still getting thge thumping from 3rd to 4th? That's the worrying bit.

[mark_i]

yes, still getting the thud from 3rd to 4th... valve or clutch i wonder?
its irritating since otherwise the car is perfect as my daily after i front ended the red iS.
ah well, i got a switchable slushbox and loom i can use when i get a weekend free to do the swap.