Zf Problem - Wont Engage Manual Shift Mode

[Moose]

Hey guys,

Have posted this before and no one had seemed to have seen the problem, had them problem them selves or had any idea what may have been wrong.

Ford have had a look at this, and told me after I got it custom tuned, if the issues wasn't sorted to come back. (read further to find out more)

So, here's the story. Around 12 months back I blew my diff (2.73 gears - standard) and had the whole diff & axle setup replaced, and went to 3.46 gears. The very day after getting it back, the gear box has been playing up. When I go to select manual shift (knocking the stick over) it just stays in drive and doesn't allow me to select the gears. After driving the car for say 15-20 minutes, the gears will then work, and keep working. It may take a bit of playing around (manual to auto mode back and forth a few times, up and down the gears a few times) before it will hold a said gear and display on the dash, but once it does its right.

Then if I drive the car around for a while and turn it off for 1 hour or more, the gears then wont work. Or, it will only take a few minutes of driving before they work. If its left over night, I gotta start all over again.

Now, ford had a look at it, and they did originally fix the problem for 2 days, but then after it started again, and they looked at it again, they have since said there must be a different fault causing the same problem, as what they fixed last time is still ok, and now they cannot figure out what is wrong. They suggested maybe getting the new diff ratio tuned in would fix the problem - how ever ChipTorque were unable to fix the problem this way.

So, my last option now is to go back to ford, and say WTF.

Has anyone had any similar problems? Is there anything I can try fix/replace/check etc?

Cheers, Mitch.

[trevs]

first off im no ford tech or zf tech

I could be wrong but wouldnt the abs sensors in rear tell the ecu when to apply traction control ......is your diff still an lsd

im guessing the zf gearbox has a heap of speed sensors connected to its little computer linked also by the ecu from the engine using the abs sensors from the rear wheels helping the car to know when to change gears and apply traction control you would think the car has to know its running differant size diff gears to work

are you sure your diff gears are 3.46 ?

now here is my guess ford are a pack of retards so you have no chance of them fixing it and having a guess its only started working again because one of the work shop retards was under your car bashing things and pulling wires and by luck only it started working just like it works when you drive it around for a while

first off can the ecu be flashed to know to it has 3.46 diff gears (can somebody who tunes these cars answer this please )

im not a tuner by any means but im thinking it has already been done other wise why would it work then not work

im thinking you have a bad connection somewhere

there has to be some micro switches connected to the gear shift knob that's the first place id be looking next up

check all cables coming off the gearbox both ends and also look for damage on them

the fact your diff was removed makes me think maybe the abs sensors have been damaged check these also did they drop out your gearbox while fixing the diff ?

cheers trev

[Benji_vs]

Maybe changing to the shorter gears have caused the box to confuse itself. Why did you go to 3.46? First gear is short enough as it is.

[Paulie2256]

To me what you have described seems to be consistent and not intermittent. You have mentioned that the box wont let you manually select gears just after start-up. From experience I know that the box wont let you switch to performance or manual mode until it has reached operating temp.

This is usually 1-3 mins.

Yours seems to be doing the same thing but with a longer timeframe. I would be looking at either the programming or the sensor responsible for this.

Just my idea

[discostig]

Mine switches straight away when cold, have never had it refuse before? Will test it tomrrow morn on the way to XFT!

Edited 17/05/10 12:11 PM by -SteveR-

[Paulie2256]

hey steve, that's weird. Dont know about anyone else with a zf. Maybe a few others could try it.

Start your car first thing in the morning and throw the shifter to the left. Does the "PERF" indicator come on?

Then try to select a gear manually and let us know what happens

[F6_Tornado]

Hard to say without testing myself but it DEFINITELY won’t be the Diff Ratio as it has little to do with the Transmission and nothing to do with the mode.

The transmission has its own two sensors internal and I know of a couple of guys who have changed the diff ratio without any dramas at all.

Sounds like an electrical fault and maybe just the selector… find a mate with same car and swap over the selector in the console.

[Moose]

snip

cheers trev

Thanks Trev, but none of that sounded like the problem at hand. Deff an LSD, spent $7,500 for a full heavy duty 'almost drag built' diff setup so it'd wanna be.

Maybe changing to the shorter gears have caused the box to confuse itself. Why did you go to 3.46? First gear is short enough as it is.

Roughly what I was thinking too - as for why? I blew the whole rear end (diff, bushes, mounts, axles) so I had to replace it, upgraded it to heavy duty billet (everything billet) and went to 3.46 ratio's because I can/could at the time (is massively worth it when you notice the difference )

To me what you have described seems to be consistent and not intermittent. You have mentioned that the box wont let you manually select gears just after start-up. From experience I know that the box wont let you switch to performance or manual mode until it has reached operating temp.

This is usually 1-3 mins.

Yours seems to be doing the same thing but with a longer timeframe. I would be looking at either the programming or the sensor responsible for this.

Just my idea

100% spot on, it is consistent, its exactly the same, time and time again, with no changes. For the heating up thing, I can remember never having to do this before either?!

So im really lost on whats causing the problems :(

[discostig]

Tried it this morning, car on, backed out and turned around on property, about 20 seconds after starting I hit perf and engaged second, yep...first...yep. Shoulda backed it in the garage to make it possible to stick it in manual straight up but I don't think it warmed up much during the backout!

My turbo needs replacing though so I'm not trouble free Warranty just about to expire too!

Good luck with the ZF - I pray I don't have any drama's with mine. Will be getting it serviced once warranty is dead and I'm modded that's for sure.

Edited 18/05/10 01:42 PM by -SteveR-

[Benji_vs]

hey steve, that's weird. Dont know about anyone else with a zf. Maybe a few others could try it.

Start your car first thing in the morning and throw the shifter to the left. Does the "PERF" indicator come on?

Then try to select a gear manually and let us know what happens

Ha Your right it doesn't, after a couple of minutes it does.

Never knew that.