Transmission problem shifiting into 6th gear when getting onto highway. Jaguar did all test and found no fault codes for transmission. If I drive slow it will shift ok but any excellerate over 2500 rpms it will not shift in 6th gear. If iam on the highway it will finally shift to 6th gear at about 85 mph. It is not in s mode. It will also shift into 6th gear if I pull it to 5th manually and go back to drive. 10 hours at Jaguar and they dont know how to fix the problem. Anyone know of this problem? 2004 xj8. Tx

 

Ensure your tires have nearly the same tread depth on both sides. Different depths can initiate "cornering" mode, and the car may not upshift because it thinks you are in a corner.

 

I do have new tires three mouths ago but will check. thanks

 

Hi tiaaa, I have moved your post to here, because you say you have a 2004 XJ8. Hopefully more people will see it. (but please avoid making multiple posts about the same issue in other forums, it will just dilute any replies and can lead to confusion).

Hope you can get your problem fixed soon, and please post up the solution when you find it.

All the best,

 

Jagtec1,
Checked tires and everything ok. what do you thijk would be my next step? thanks much

 

If the car is under warranty I would find another dealer.

If not I would find a small, local, independant, auto transmission specialist and go and talk to them.

 

after 10 hrs at jag dealer and five days at tranny shop know one could fix problem. was not shifting out of 4th and 5 th gear with moderate driving. If driven slow it would go into 6th gear. Jagtec1 told me to check tire debth which i did. Front had about 80% and rear had about 90%. the wear looked good. I switched tires front to rear and bingo. Shifts every time to 6th reguardless how i drive. Its hard to believe that solved the problem. This had been going on for months. Thanks to Jagtec1 he solved the problem!!!!!!!!!! Thanks Jagtec1. Bob

 

Wow


You should gave added this to the bottom of your Jaguar Cant fix thread though as its a cure for that problem...doh!

 

Thats great to hear!! Did you compare the thread depth from left to right or only front to rear? I'm curious if one would have this problem with different sized rims? I thought about putting different sized rear tires on and this might cause a problem.

 

Drew,

If you go with staggered rim diameters, you want to make sure the overall tire diameters are close to the same as fronts. There will be ABS issues too if the wheels are not spinning within a 15% rpm variance as an overall limit, and Jaguars might be even tighter. The ABS interprets such variation as wheel spin.

There are some good aspect ratio calculators online. They can get you very close to zero % variation with staggered rim diameters.

 

Thank you,
I'll keep that in mind.