ZF gearbox faults, root causes & Troubleshooting
 

With ref to Jim's request for stickies I think

that this should be included:

Everything about your ZF 6HP26, 6HP19, 6HP28 transmission issues | BMW LOGIC7

Agreed and should be a sticky in the X150 forum as well. Thanks for posting.

Interestingly, there is a link for testing out the MOST BUS network too which would also benefit X150 owners.

This should also be added if it isn't already.

Thought I could add a comment here on what I suffered

04 xj8 n/a

(She) cat threw the abs light

10 miles later , cat went into transmission gear faults and basically wouldn't shift out of second gear . Felt incredibly a bit like the trans was toast clanks and squeals and all kinda sh!t. So I replaced the driver rear abs sensor with a rock auto part and boom , all was perfect again


transmission didn't like what the abs sensor wasn't saying and acted up for it

spread the wealth guy's .
this should definitely be in the s type stickies as well !!!

thanks

Last week a similar series of events happened to my 2008 XJR. Trip #1 ABS fault & 20 miles home. Trip #2 ck engine light on start, after 2nd shopping stop 2nd, neutral, repeat, repeat, gearbox fault and 10 miles home in 2nd. Car has been at dealer for 3 1/2 days. Haven't heard anything.

I did get dreaded transmission codes as well as body module ones one day. Threw about 6 codes in total as I recall. Turned out to be a broken wire in the top of the left front shock on my 01' xkr.

As discussed in the thread - "What's the mileage on your ZF 6HP gearbox ???" - posted by Supersprint - here is a link to the Jaguar adaption procedure (TSB JTB00145) - which can be printed off and shown to your Jaguar dealer.

http://www.justanswer.com/uploads/cr...00145NAS11.pdf

I will be looking into having this done on my XK8 in order to help eliminate the occasional harsh gear change problem. I'll let you know how I get on.

I have heard about this adaptation procedure. I am still getting an occasional squawk when the car downshifts from 6 to 5 and sometimes accompanied by a 5/6 gear ratio error message despite twice doing a fluid filter change. Only happens during a gentle downshift from 6 to 5. Not during a hard one.
Think this might help with that issue?
No harsh shifting issues.

What ATF did you utilize when you did your pan drop and fluid refresh?

Sorry but I have no idea....this adaption procedure is all new to me and seems to be addressing the harsh shift issue...so I don't know if it will help your transmission.

Hey Jon89
I did it once with the Ford Mercon that they used in their ZF cars and did it again with Lifeguard 6.
40 degrees C and a slow drain out of the filler plug when I closed it up

ZF gear box acts weird
 

ZF gear box acts weird. Backing, sounds like
i'm hitting something.

So the gearbox fried on my 1997 XK8, mechanic told me it needed to be replaced. I didn't have the cash for a rebuilt one so I bought a used one and had it professionally installed.

It worked well to start but I noticed when I shifted from reverse to drive without fully stopping, I got the dreaded transmission fault. Turning the car off and then on again returned it to normal the first time, but the second time I had to let the car sit for a few days before it decided to magically work again. It took about three times for me to realize the bad shift was what triggered it so I was careful when shifting from then on out.

However, yesterday it faulted twice: once when I was driving normally in city traffic, and then again when stopped at idle in a parking lot. I'm worried that this used transmission that has been in for 9 months with less than 1000 miles is going to go up again.

So, any ideas? I'll add that I also had the car in to diagnose some strange whines and they suggested it was likely coming from the transmission.

HELP! I love my car but it's frustrating to constantly worry it's going to die on me.

what wasthe end result?

Glad I joined this forum. I'm new to the car, a 99 XK8. I'm working with a shop and they have it down to 5 codes (from about 15). The most serious they say are the check engine light, a phantom misfire code and an ABS fail code.

The trans still won't engage except in a high gear. No noises, just no power to the wheels. The engine seems to work fine. They are first concentrating on the misfire code.

The dealer had said one of the wheel speed senors was broken and the module was not reading properly.

Could the ABS situation may be more related to this issue than the misfire code? Any thoughts would be appreciated.

Hi ArtI,

Yes

Suggest you post this as a new thread in the 'Normal threads' rather than here in the stickies, or ask one of our tireless mods to move it for you.

Good luck,
Mike

A few of us have found that if your tranny's going into limp mode along with some sporadic ABS a/o Cruise Control warnings, check your rear wheel bearings before you do anything else. The wheels will actually start to wiggle around long before you hear any sounds of the bearings failing, and that wiggling will throw all sorts of warnings through the ABS sensors. Many folks have replaced transmissions when the only problem was worn bearings.

Andyzeg
Did you ever do this adaptation procedure? Did it help anything?
The link to the procedure you posted does not seem to work any more. Do you have a copy of it?
Thanks

Here's a working copy -

hello andyzeg...and all,

i have just purchased a 2005 xkr with 75k miles. i bought it knowing it has a coolant issue of some kind (i can smell it however no indication of overheat nor able to see where the leak/ seep maybe) and a transmission issue (it drives fine).
Last jag i had (40 years ago) was a '62 e-type coupe...LUV'D that car....jag fan ever since ! I have luvd the xk8/ xkr's since '97 because they remind me soooo much of the most luv'd car i ever had...i ramble...

ANDY ! this post is 10 months or so old and will not open for me...would you be able to post it again?... I am trying to learn all possible before finding the right shop to open my ZF6HP26.... I thank you ALL for being active and helpful to my new community of enthusiasts; a tremendous help to me already !

It's the same as the one in post #19, that one works.

ZF gearbox faults versus LED brake light
 

Let me explain my recent experience with LED brake light. After changing my regular brake light for LED, I found my 2006 XK8 sending a Dashboard message For check brake light. I didn’t install the resistance at that time so I said, I will just clear the message.

On weekends i went for a nice road trip and and found the beautiful Jaguar electrical nightmare! My transmission was not sifting At all while on D when leaving the stop sign. I had to shift manually or remove the Sport mode, then move up until 3000 rpm, lift the throttle pedal then it work.

Cruise control was not working either. So next morning I tought that all this happens after putting 2 LED brake light so I put back the regular 7258 bulb in place.

I went for a road test and suddenly everything was back in perfect condition. The gearbox was working as it is suppose even on Sport mode, Cruise control was working perfectly and the dashboard message was gone. So Jaguar is a very sensitive CAT to any electrical fault.

So be careful if you want to use LED bulb, you could find yourself with others issues that you had never planned.

Reason No. 1,289 to stick with the OEM specs in these electrical systems....

Good info. Thanks.

Very interesting!. Clearly, the tinkering you did with new LED brake lights made the Transmission think vehicle was braking. The Transmission Control Module is fed status (Via CAN BUS) regarding the braking condition and will not enable ratio change-up if the brake lights are on. This is irrespective of engine revs and whether you are actually braking or not. So the brake light circuit is key.

As you know, when you depress brake, the pedal switch turns on the brake lights, but also, the system is looking for volt drop to check bulb health. It was this closed circuit that was somehow being fooled and affecting your Transmission operation!

In standard brake light set-up, the system is fail-safe with no affect to gearbox – but there’s one exception to be aware of in future. The brake pedal switch has a little built-in ratchet that can require resetting if the brake pedal has been pulled hard towards the seat, the ratchet will set and the brake lights come on permanently without the pedal being depressed. This situation will also cause the gearbox to not change-up in D-Drive (like your failure mode). So, if same Gearbox fault ever happens again, one check is to see if the brake lights are staying on all the time....

This is what happened to my 05 XK8 with 49,000 kms. Transmission wouldnt shift up most times and if it did into 2 it was at 5000 or a flick of the gas would also shift. I also had failure message of cruise unavailable and a rear light issue. When the ratchet is out of place the car thinks and acts like your foot is on the brake pedal. I was lucky and could at least drive the car but with mine the ratchet was just done and required a new switch where after all worked perfect. I did try a switch from a wrecker which was also faulty so be careful as the effects of the switch will appear to have a fried transmission so some people will just part out the car if it has high mileage. Best to go new with the switch,

I had not been here in a few years I do not believe, so most likely posting in the wrong place. With that my 2000 XK8 had a delayed engagement from park to drive and drive to reverse and again from a stop light to going. Not real bad but not right. NO codes!! Took the transmission out. Second time now...First was to replace rear main seal. Anyways I thought I needed clutch drum A. They are known to crack and trash your transmission. Turned out the valve body had a crack in it. Just thought I would pass the info on.
https://cimg1.ibsrv.net/gimg/www.jag...202c5be274.jpg
This is on the top side of the valve body. You have to remove the filter and valve body to check it for cracks. I saw this same crack happen before, so some what common.
https://cimg3.ibsrv.net/gimg/www.jag...a2aec64316.jpg
https://cimg7.ibsrv.net/gimg/www.jag...22b3d0e438.jpg
https://cimg0.ibsrv.net/gimg/www.jag...5126a3ed8c.jpg
Normally clutch drum A's upper cage comes apart trashing the trans. They make a more heavy duty one...

JAGUAR XK8 Automatic Transmission Neutral Safety Switch 0501211566
 

hello, i need that part for my Jag...you can help me ?
https://cimg3.ibsrv.net/gimg/www.jag...580bf2100b.jpg

ZF 5HP24 Rotary Switch Diagnosis and Repair by jim_63219
 

A great DIY for repairing the Rotary Switch thanks to jim_63219:

ZF 5HP24 Rotary Switch Diagnosis and Repair by jim_63219