Hello Chaps,

Long time no post; work has been crazy since COVID Fiasco.

Long story short I replaced all the solenoids in the ZF and it cured all the common ZF issues, oh and I didn’t use SDD to reset adaptations

Common ZF problems:

• · RPM Fluctuations (Torque Converter Lock up - Warm Up Procedure)
  • Mine was bad 500 rpms with audible sounds
• Squawk noise
• 1st to 2nd to 1st kickdown, or kick in the ***.
• Slipping, especially at cold
  • The reason why I changed my solenoids.
  • Mine was really bad, stopped engaging all gears D,R, P when cold and at a stop(i.e red light)
  • Gearbox fault thrown

Now the full story, back in October 2016 I drove to the gym on a somewhat cool morning. Running late as usual a stepped on light from a redlight, gear slipped. Tried again, slipped again and got a gearbox fault error; stuck in 2nd. I made to the gym; hit the body bags to let off my new steam. After the gym got back in the car and drove fine. This was the start of my slip saga. Basically if it was cold out and moderate use of the petal would cause a slip from 2 to 3. Progressively got worse with winter but would sort itself once the transmission got warm enough. In the meantime I had to hold the shifter in 2 rev a little, let go of gas and move shifter to 3 to prevent slippage. December 2016 I took to an independent to reset TCM, he also upgraded the firmware. The firmware upgrade did resolve the slipping but I did notice a difference in the Torque Converter Warmup procedure. The transmission would now hold down gears longer when in cold to minimize RPM fluctuation, but it still fluctuated RPMs just not as bad. Circa 2017, I went ahead and replaced the mechatronic bridge seal along with fresh fluid with no luck. I later went back in, circa winter 2017 or early 2018, and changed the tube seals next the mechatronic bridge seal and fresh fluid. No luck. Slippage has been getting worse with every year now affecting 3-4 slip as well. By winter of 2018 I would have to start the car, quickly throw it in gear and takeoff and prey for no red lights. If I got stuck at a redlight after a few seconds the transmission would disengage gear; not enough fluid pressure. I would have to restart the car and takeoff again at green light.

I finally bit the bullet for Christmas 2019, I ordered genuine solenoids, tube seals, bridge seal, and mechatronic sleeve; all from CTSC. I would’ve also gotten a zip kit(rock auto has them) but didn’t have my specific valve body plate number handy and didn’t want to chance it. If you get this far I would advise adding a zip kit. The solenoids come with an instruction sheet that’s easy to follow that shows you how to remove the valvebody and then TCM from valvebody. Be careful not rub your socks on carpet as static discharge can brick the TCM. Once TCM is removed a brace that secures the solenoids is removed, couple of bolts, and the solenoids are pulled off. Push the new one in where they go and align the flat sides with a straight edge and push them in until they pop in all the way. Then button everything back together. Side note, the solenoids come with a foam strip that installs by their electric pins to protect them. Some early build transmissions did not have this foam, it was added on later builds. Mine had it (04). Either way make sure to install it, don’t throw it away thinking it’s packaging.

I refilled the transmission according to procedure; which is by far the hardest part of this whole ordeal. I started her up and drove around the neighborhood and guess what. It was doing the exact same thing. My heart sank. I knew I should have a TCM adaptations reset but surely if it was the solenoids the transmission would at least behaved differently. I would attempt to drive gently to 1200 rpm, but it would still slip and also disengage at a stop. Anyways I decided to keep driving as usual, and by the 3rd day I attempted to leave it in D again and it started shifting, a little rough but it was shifting. For 500 miles I kept her between 1200-1500 rpm each day shifting better. By the 5th day, 4th 5th & 6th were engaging smoothly; 1 to 2nd and 3rd was about 90% there. After a week all gears were shifting smoothly. At 700 miles I decided to try it Sport mode but not too heavy throttle. At about 900 miles I started flooring it from different gears no problem. She’s now brand new and I can put away the gasoline and match sticks. I now have zero RPM fluctuation at (torque converter locking warm up), I no longer have the Squawk noise, and I no longer receive a kick in the *** after an immediate stop and takeoff and no more slipping!

I know you are wondering why the heck I kept driving it like this for so long and why didn’t he get the adaptations reset immediately after replacing solenoids. Well it’s my daily driver and I need it to go to work everyday and I live in an apartment building so can’t have an extra car here. It was Christmas time when I replaced the solenoids so it would be a few days before the shop would be available for it and I have a cheap clone mongoose(too risky). The transmission is always adapting; just very slowly.

Side note for diagnosing transmission issues, always check for misfires first, plugs and coils first. My very first slip circa. 2014 or 2015 can’t really remember was due to misfires. For some reason the jag does not easily throw misfire codes, so you may not know you have a misfire until it’s a bad one. Also inspect plug wells for signs of oil. If oil is present replace the valve/cam cover gasket and plug seals. The oil will eventually short out and ruin the coils thus fouling the spark plugs, know from experience as well. If you’re doing a transmission refill for whatever reason, go ahead and replace the sleeve, tubes and mechatronic bridge seals while you’re at it, it’s easier than the refill procedure itself and you’re already there. Only use genuine parts, I got mine from CTSC. I had a cheap mechatronic sleeve seal fail on me within 2 years after parking on a steep incline; got fluid in the connectors and was stuck in 3rd gear. I had to disconnect battery, sprayed contacts down with electronics cleaner and clear codes to get it working again. I have been using Mercon SP as fluid since my first refill 5 or 6 years ago. This marks I believe the 4th time I had to refill the transmission, each time with Mercon SP. I strongly recommend using a ¼ inch torque wrench to torque all the screws and bolts. The first time I replace my pan I broke a bolt and had to drill it out, they’re very soft.

Sorry for the long story but figured it may be useful for the next person. Enjoy a couple of the pics attached.

 

BlacKat,
Nice work! Happy you are back in operational condition again.
I'm glad you took it easy on the clutches during all that slipping.
I recently did similar work to my '04 XJR as well. Using ZF parts was expensive, but I reasoned that if I have other major transmission problems, the valve body is done already and I could use that (with a trans rebuild if needed) for another 100k.
Notice how heat faded the blue solenoids are in your photos. Mine looked similar. I have read that the problem with solenoids is likely to be caused by debris fouling from lack of oil changes. It didn't help that auto MFG took that "sealed for life" position.
Thanks for sharing the information including your experience with shift adaptations.

Dan

 

great write up. Old post i know but i just came across it. I recently did the same repairs on my 06 str. All parts from ctsc. I also replaced the separator plate on klaus advice along with the rubber dampers. My original problem was a severe slip in sport mode at near or full throttle. I did not do the complete easy driving for at least 300 miles. The problem was better but not solved. I contacted klaus again and he said clear adapts then reflash tcm then follow drive cycle to the letter. I have sdd with a genuine mongoose and a snap on modis to read clutch fill pressures. He also said no sport mode for those 300 miles. I am 200 miles into the drive cycle and everything is beautiful. Clutch fill pressures so far are great as i sent them to klaus and he is amazed because i have 171000 miles on the car. I will continue to finish the drive cycle correctly. It is trying my patience a little because i do not drive very far. That had been my shortcoming previously. I would go sport early and push it too quickly. Do you feel extending your drive cycle miles made the difference for the trans to be perfect again

 

Hi !

I stumbled upon your post, looking for solutions for a problem I got after I didn't drive my XJS'95 for two years. while on the road for the first time one of the water cooling hoses broke, and sprayed coolant over the engine. The hose that broke, was the shirt one going from the cilinder head to the heater valve. In your post about transmission problems, I read that you had fluids coming somewhere, and that your gear was stuck in third gear from then on, and that you had to clean contacts. After my leakage, I had the same problem. The gear is stuck in third gear and I get a fault code saying shift solenoids A and B and another one are defect. . I can't believe this is a coincidence .so because I can't really understand which part got wet in your case maybe you can help me finding a solution for my problem so once more what happened was that coolant came in contact with some electronics somewhere I think, causing the gear getting stuck in third gear. This happened exactly after the leakage . I get a solenoids an and B, warning light. This is the part that you wrote that caught my attention. Thank you very much , Pim!

. I had a cheap mechatronic sleeve seal fail on me within 2 years after parking on a steep incline; got fluid in the connectors and was stuck in 3rd gear. I had to disconnect battery, sprayed contacts down with electronics cleaner and clear codes to get it working again. I have been using Mercon SP as fluid since my first refill 5 or 6 years ago. This marks I believe the 4th time I had to refill the transmission, each time with Mercon SP. I strongly recommend using a ¼ inch torque wrench to torque all the screws and bolts. The first time I replace my pan I broke a bolt and had to drill it out, they’re very soft.

Sorry for the long story but figured it may be useful for the next person. Enjoy a couple of the pics attached.




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