Good afternoon everyone. I'm new to Jaguar ownership having purchased a 2005 Super V8 (i.e. XJ X350) over the summer via BAT. The hope was to find a truly special car that I could share with my entire family, the wife and little ones (10 & 8), at the same time since my Mazda's ('04 Mazdaspeed Miata & '93 R1 RX-7) are not what one would call family friendly. The Super V8 seemed the answer as I've long admired the XJR's and Super V8's. I tend to hold onto cars for extended periods and I entered into Jaguar ownership with the intention of this one being a "keeper".

I was initially impressed with much of the car after taking delivery. The body was in great shape, zero rust. Excellent interior. Seemed to run well initially but then experienced a coolant temp spike over a particularly hot summer day and also a leaky air suspension. Wound up replacing two corners of the air suspension (the two others had just recently been done under prior ownership), the radiator fan unit, and various sundry maintenance items (i.e. bushings, hoses, etc.) in addition to regular gambit of new to me car fluids and filters across the board. With that behind me, and the ancient tires awaiting replacement when spring hits NE Ohio,
I was just about ready to put it away for the winter when the transmission began slipping (when rolling into the gas above 3,500 RPM or so) and going into limp-home mode. I was able to restart the car, which popped it back out of limp home, only to have it do so again under load. This was after the local independent Jag specialist (long-time former Jag master tech at the local dealer) dropped the pan and swapped out the fluid and filter. We did attempt to use a friction modifier additive as a last resort under his recommendation but to no avail.

All that said, any advice/direction that the forum members might be willing to offer me would be tremendously appreciated. If there is a pathway to a potential solution that does not involve a full rebuild I'd be over the moon to hear about it. I have explored other options including:

• Speaking to Sparrow Racing in the UK to explore whether they had a manual swap kit using the European market diesel manual transmission (watched DriveTribe's piece on their XKR) but they have no plans to do the software work for the XJ's as they don't believe the demand will be there to justify the development costs. Too bad really...that would have been fun and unique.
• Opting for a used unit from a reputable source but I believe that will need to be programmed after install and the same Jag specialist independent mechanic noted above does not have the programmer, suggested that the local Jag dealers are reluctant to work on cars of this vintage and suggested that the rebuild route was probably a better, and less risky, option. When knowledgeable folks offer recommendations that go contrary to their personal bottom lines, I tend to take them seriously.

I took it to a well respected local transmission shop and they suggested that I'm in need of a rebuild. Below is a summary of their findings for your reference.

Problem Statement

• Trans in limp mode/OK to Lev2
• Trans slips under load in 5th gear
• Internal trans problem; Trans must come out for inspection
• Warranty does not cover Mechatronic inside trans
• Codes present: (note: I did my best to post the code descriptions in an attempt to be helpful but I'm not sure if they are correct.)
  • Trans:
    • P0735 - incorrect gear ratio code for 5th gear
    • P0730 - incorrect gear ratio detected in an automatic transmission
  • Engine: (note: I believe all these to be legacy [i.e. not present at the time of the transmission diagnostic session] that likely came up as a function of the work done immediately prior by the Jag specialist.)
    • P1260 - Security input./Theft detected, vehicle immobilized./Theft detected - engine disabled
    • P0480 - cooling fan 1 control circuit has a malfunction
    • P0568 - Cruise Control Set Signal Malfunction
    • P1696 - Speed control input switch fault

Description: Level 2 diagnostics. Scan check/text for codes present. Check all related wiring and connections from trans to PCM. Check fluid level and condition. Trans slips under load in 5th gear. Internal trans issue and needs rebuilt to repair.

Repair Cost Estimate: $3,500-$5,000.

A sincere thank you to everyone in advance for taking a moment to offer your insights/wisdom to a newbie.

 

Welcome to the forums Ohio's Jag,

I've copied your Intro post to X350 forum for advice from members with the same model.

Graham

 

You may have a bad reading from the left rear sensor. The wheel speed not matching expected from transmission out put. Could be ring/sensor/connector.

 

Too bad that you have so much trouble with the beautiful vehicle.
About the transmission:
I have 3 vehicles with the ZF6HP26 (XK8, X358 and BMW 330i) mileage 80 -125k miles. None of them causes any problems.
I think it is very unusual, to say the least, that the transmission in your vehicle shows such signs of wear at just 75k miles. Also noticeable that the problem occurred shortly after a transmission oil change.

P0735 indicates too much slippage in the clutch for the 5th gear. Cause does not necessarily have to be wear on the clutch, it can also be an actuator or transmission oil problem.
It has nothing to do with the rear left wheel sensor, the transmission monitors clutch slippage with internal input and output shaft speed sensors.
Regarding the used unit option: after changing the transmission, it does not need to be programmed. At most, a long drive cycle is required.

I think that an overhaul of the gearbox is not really necessary with the mileage and would first research further. Which oil has come in, have the instructions given by ZF been followed when changing the oil (shifting through the gears, oil temperature when filling, etc)? Also, I would ask a specialist who knows the ZF transmissions and their problems well.

Another option would be to flush the transmission and change the seals and the shift valves (mechatronic), possible without removing the trans. But this costs about 1000 -1200 $ and there is no guarantee that the error is eliminated.

Fritz

 

eclutch problems are not uncommon especially if it had a leak. some barely make it to 50k others make it to 500


used tranny out of an xk or xf 4.2 supercharged bolt the old tcm in and you’re good to go.