Transmissions question (ZF 5 speed)

X5UK88 · #1 03-24-2017, 12:44 PM

Hi guys,

I've noticed my X5 will accelerate better under part throttle when down low in the rev range as opposed to flooring it. If I give it part throttle whilst just cruising in say 5th it'll pick up smoothly, if I give it almost full throttle before it drops any gears, I almost feel a bit of resistance and it doesn't go like it would on part throttle, then it'll start to take off over 3k ish if I remember rightly.

It's quite hard to explain hopefully I've got it across.

Is this normal behaviour or does it sound like an issue of some sort? Or could it even be the engine?

Thanks in advance for any replies.

smokeyyank · #2 03-24-2017, 01:48 PM

So, if you're at cruising speed say 65 in 5th and give it some gas it accelerates fine and if you mash down the gas it delays before dropping a gear? Does it do it in every gear or just certain ones?

X5UK88 · #3 03-24-2017, 05:43 PM

Quote:

Originally Posted by smokeyyank

So, if you're at cruising speed say 65 in 5th and give it some gas it accelerates fine and if you mash down the gas it delays before dropping a gear? Does it do it in every gear or just certain ones?

No sorry. It'll drop down a gear if I floor it. If for instance I give it say 1/4 throttle it seems to pick up better than 1/2-3/4 throttle, I feel resistance and it feels a bit sluggish and then starts to pick up after that. If I floor it it'll drop down fine and take off.

I didn't know if this was another zf quirk..

upallnight · #4 03-25-2017, 11:16 AM

Quote:

Originally Posted by X5UK88

No sorry. It'll drop down a gear if I floor it. If for instance I give it say 1/4 throttle it seems to pick up better than 1/2-3/4 throttle, I feel resistance and it feels a bit sluggish and then starts to pick up after that. If I floor it it'll drop down fine and take off.

I didn't know if this was another zf quirk..

Unless you are doing 120 mph when you mash the accelerator, mashing the accelerator normally drop down a gear. This is design so that the engine will rev and produce more power for passing. People who drives sticks know to drop down a gear before mashing the accelerator.

four.8is · #5 03-25-2017, 01:23 AM

when in mood and time comes to clean up the exhaust, I always floor it. That way theres no confusion it just goes.
On a more serious note, I get what youre saying, my 6 speed ZF does the same. I just consider it "normal" behavior.

X5UK88 · #6 03-27-2017, 05:24 PM

Another transmission related question..

I've noticed for the first couple of gear changes when the box goes to change it makes a noise similar to a power steering pump running dry.

Now I've noticed it it's starting to worry me, it's only first the first couple of cold gear changes but even so it's still not right. Oddly the car shifts well....

four.8is · #7 03-27-2017, 06:13 PM

A whining noise? Mine does it too, some say it has something to do with the torque converter , I'm not sure though; my tranny shift excellent, with a few exceptions when I abuse it and on super steep hills.

X5UK88 · #8 03-28-2017, 03:08 PM

Quote:

Originally Posted by four.8is

A whining noise? Mine does it too, some say it has something to do with the torque converter , I'm not sure though; my tranny shift excellent, with a few exceptions when I abuse it and on super steep hills.

Yeah I guess it is a whining but it's literally only when it goes to change gear, not constant. Doesn't sound great. I wondered if it may be the sound of low fluid, but then I've been told of the fluid was that low the changes would be horrendous. Yeah I get the odd poor change, if I floor it and then change my mind it hates it haha.