Zf 6 Speed Auto Not Changing From 3Rd T 4Th

[Paulie2256]

It could be a bazillion things...

[F6turbo]

If it is the clutch pack does that require a gearbox rebuild or can they be changed?

Rebuild, mine does the same

Is there a reason why the friction and steel plates cannot be replaced for new items in clutch pack E on their own? I dont see why a full rebuild is needed unless you wanted to beef up the trans...?

[Vevapower]

Is there a reason why the friction and steel plates cannot be replaced for new items in clutch pack E on their own? I dont see why a full rebuild is needed unless you wanted to beef up the trans...?

Seeing the rest of the frictions and steels are only another $100 why wouldnt you do the lot! It's the labour and oil the pump it up!

Edited 18/08/12 11:24 AM by Vevapower

[F6turbo]

I'm thinking DIY, get in there and change just the worn out parts yourself. Why pay 5k or so for a small issue such as slip in 4th.

[Vevapower]

Yeah you could do dyi for sure. Though if you fnd that there's a fair bit of sh*t in the oil and pan it would also be a good idea to put new solenoids in as well. Actually parts alone on a simple re build are around $1700

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[PookeyMaster]

Plus, consider how long you'll be spending looking at manuals if you've never done a transmission before...

[Timmy-XR6T]

Mechatronic only reacts to its physical components,oil characteristics and sensors so to say its the mechatronic itself is not correct. If all componentary wise in your box was fine you would not have any issues with slip yeah! You see once you burnt up frictions there's no way they'll come good again and they just get worse. So what's happening in your box atm under load between 3rd to 4th is that due to the slip (E clutches in bad shape) the speed sensors are saying to the mechatronic " hey man there's way to much slip going on here so there's no way I'm going to let it change up to 4th". So what usually happens is that it will either rev out or you inadvertently lift off enough whilst this is happening enough to lower the load enough for the mechatronic to then say hey I'm good now and it will thud into 4th.

Now as wear continues to get worse over time it will refuse to change under less and less load.

A ZF tune might mask it for a while with more line pressure but in time you will still have the same result.

Hope this gives you a little bit of insight.

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Fair comments - I had very similar issues 3rd->4th on WOT, and then later 5th and 6th were slipping. I had a service and tune which seemed to improve (read mask) it but after a while it all started to give way.

Now I've gone the rebuild it feels allot stronger and now booking in for a retune of the ZF to get it running smoothly as the old tune is still compensating for the old issues I had.

My two cents, bite the bullet, just rebuild it and save all the hassle with everything else. If its burning out now its only a matter of time before it gets worse.

[mr_crust]

well had it looked at today the issue was due to having a 19" rim on the front right and the factory spare 17" on the front left (valve stem popped of that's why I have mismatched rims)...Ford explained due to the size difference the the car thinks its constantly turning therefore wont allow it to move from 3rd to 4th whilst in drive, which explains why I can make the decisions and move into 4th using perf mode.... as soon as I put the 19" back on, It allows me to shift as normal..so I'm replacing all 4 tyres with Michelin pilot super sports :)

Edited 20/08/12 04:08 AM by mr_crust

[Paulie2256]

Fooked mechatronics...

Well you were sort of right with this one. At least the closest to the truth. haha

[mr_crust]

im just surprised there is a sensor which detects it, he mentioned the abs sensor ...basically from my understanding is that the drive gear will not upshift when in 3rd of higher if the car is turning state....