I just got back from having my transmission serviced with new filter and the pressure regulator valve changed to the updated version. The work was done at the Dunn Transmission company in Tyler, Texas. This company has been in the transmission business since 1950 and is credited with several awards. Doing the work with Chad Dickerson was a very enjoyeable experience. He had never worked on a valve body with the transmission still in the car, but seemed to be looking forward to doing it. Along with some of my information from the forum and his manuals the job went flawlessly. We removed the lower front valve body where the valves were located and changed the old pressure regulator for the new one. Took both of us to compress that spring back down.

When we had the old valve out I compared the new with the old. There is very little difference. In fact the only difference is in the last land opposite end of the spring. I didn't have a way to measure the difference as we were working. But I did measure the width of the old one after I got home and it is 0.353 inches wide. If someone has a modified one I would like for them to measure the width of that last land for comparision and let me know.

If you have and XK8 that needs the trans serviced and the pressure regulator valve updated, and you live near Tyler, Texas Dunn is the place to go and Chad is a great guy to work with. We both seemed to have fun doing the job. Since I provided all the parts and oil the bill was for two hours labor at $75.00 per hour. I'll be taking my 95 XJ6 there in the near future to have it serviced also. I highly recommend this shop.

 

Did the same thing with my XK8, except that I bought a rebuilt valve body from Sunbelt Valve Body Builders in FL. In researching this, I found that you can buy a kit with which you bore out the pressure regulating valve opening and install an oversize valve. It was very tempting, but I couldn't figure out how to keep the metal shavings from migrating through the valve body with horrendous results. Because of pending shoulder surgery I had the work done by a local indie Jag mechanic in Malvern, PA. Expensive, but piece of mind..........priceless!

 

When we removed the valve I looked at the bore and it was flawless. No scoreing that I could see and we looked really close. With 54K miles on it now I think it will last for a lot more if I keep the oil changed. And the pan magnets had very little stuff on them. Chad said it looked really good to him. Guess I'm lucky.