ZF Shifting issues

[Joshuam08]

ZF Service - never had one, so I'm getting it done soon but I'm not sure if that'll fix the issue. Only at 80k so not a lot.

Normal service - a month ago

[bjc]

I'd say it's normally mate. I've got a turbo Territory and it does the same with part throttle. The ba turbo with btr even did something similar although it only had 4 gears....
I believe what it does is hesitate for the amount of throttle you are giving it (adaptive learning?) then realises it's not going to receive more torque/throttle input so then shifts off the convertor and up a gear or two, if you understand my explanation!? The Territory is easier to pick it as being awd there's more slack in more places so that hammer effect is accentuated....lol fcken car be the death of me!!!

Are you keeping that throttle input constant or are you feeding it the 60% etc then backing off slightly once up to speed? I ask as if you're backing off slightly at a set point (2nd gear 3000rpm for instance) it will make that change even worse from convertor/ 2nd gear up to 3rd and 4th quickly. As the blokes above said, some slack in the driveline will make this appear worse but I highly doubt you'll hurt the ZF as I've tried and replacement front diff was my only issue!

Anyway....that's my thoughts on it.

[Joshuam08]

Hey mate, I should add that this happens in manual shifting mode as well so I'm not sure if it would be the trans trying to go up a few gears but I do understand what you're saying. It seems to happen when I maintain the medium throttle input, if I back off the throttle a little bit before the 3-4 shift (generally around 70km/h) then it is back to being fairly smooth.

[bjc]

I would say then that it's a standard feature of the transmission. At a set percentage the firmness of the shift may be set the same as full throttle or full engine torque and so feels more violent when only 60% throttle is applied. This was something that my tuner (Dave Sheehy @ CPV, AKA Blueboost) for my BA turbo set so the standard BTR survived. It shifted violently the whole time so it was something I got used to and although concerned for other parts the diff and bushes never had an issue.
Have you tried resetting the ECU via battery disconnect? I'm not sure it would change anything but you never know with the complexity of it!
Also to test for driveline lash/slack you could cruise along in 4th or whatever and and get on/off the throttle to jerk the car and see how noisy it is. I don't recommend doing it for 10kms but 5 or 6 times and you'll know....
That ZF will take a lot of punishment so I wouldn't be concerned it's the transmission that has a fault for shifting to hard unless you feel your bones ache, then it may be overdone!

[Joshuam08]

It's going back in for a ZF service in a week so I might check with the tuner then. The tuner did say they would firm up the shifts so possibly my definition of firm isn't correct. I just wasn't sure if it was normal or not mostly because I assumed firm meant more noticeable and rough but still 'smooth' and within the trans. This jerk is so violent that it feels like it's coming from the whole drive train but I could be wrong. Anyway, I appreciate your advice and I'll give an update once I chat with my tuner!

[bjc]

How did you go after the service?

[Joshuam08]

Sadly no change, shifting is much smoother overall, however same issue persists.

 

I've been told I also need my engine mounts and trans mounts done too so possibly that could be the cause but unsure at this stage.

[skidxr6t]

for sure get your engine and transmission mounts done if they're stuffed. will make a huge difference...if they are stuffed.

[Joshuam08]

I'm not sure if they're totally stuffed but I think they're showing signs of surface cracks so they'll be getting done along with a few other things, such as cracked tailshaft centre bearing, and some other stuff. May be the cause, may not be. We will see next time I go back to get it fixed.

[skidxr6t]

how many ks has the car done?

 

edit: just saw 80k ? at 80k its unlikely to be the box at fault unless the oil is bad/wrong level so id definitely be looking at the drivetrain including the engine/box mounts.

 

you shouldn't have to spend too much resolving this but if the cars been thrashed then its probably due for some work haha.  Have your diff bushes been checked?

Edited 22/11/18 07:19 AM by skidxr6t