E39 autobox question

[SuperHangOn]

535 - ZF5HP24

Right well, all changes and general driving with the box are super smooth - except changing into the highest gear (40 - 50 ish) which you can sort of feel. Its not harsh or clunky, just not seamless like the other changes. It actually had the box rebuilt by a place with a good rep a few years ago (previous owner). Is this something that could be adjusted out somehow?

If the box is on the way that's pretty disappointing but the car was cheap so not the end of the world to bin it when it eventually pops.

Edited by SuperHangOn on Sunday 23 November 18:29

[roofer]

Is it not the torque converter locking in top ?

[SuperHangOn]

Thanks, hope so. Can anyone comment if there's does this? All other autos I've owned were mercs and lexii which didn't really do this

[Huff]

ZF5HP24 can have fairly simple* fluid top-up or replacement which is probably worth doing every few years; if the box works fine in other respects, it's good to go. Failures tend to show up as nasty clonky shifts at very low speeds, whirring )low fluid) and similary obvious-wrongness. NB holding gears for first mile or two when very cold is normal programmed behaviour, designed to warm the fluid. The only real problem that afflicted the 5hp24 IIRC was the input seal failure, which was prob the reason yours has been rebuilt. (poor material spec subject to update, IIRC) Apart from that, they were/are solid.

• it's the 5HP30 (used in E34 540s but not the E39s) which had the wierder/more expensive and now-deleted Shell LA fluid. And no drain plug. Even then ZF longlife fluid works fine.

[SuperHangOn]

Cheers. From a bit of googling, it seems the highest gear is an overdrive so perhaps that's why the change isn't as smooth as the others. Does anyone else here have/or owned a V8 E39 auto?

[Lowtimer]

Same box as an E38 V8, I believe.

Try asking over on the £1-£5K barge thread, there are quite a few people over there with E38 V8 experience.
http://www.pistonheads.com/gassing/topic.asp?h=0&a...

[Huff]

5th is an overdrive numerically but not a separate ratio IYSWIM, should be just as smooth as the oteh rchanges.

If this lurch were at 60mph or more it could be the torque converter lock-up, which should also be seamless (the ZF boxes of this era had a progressive lock, 2 or three steps over a speed range so very smooth). Again, before worrying about the converter I'd look at fluid level/age and filter.