What ATF is recommended by Jaguar or ZF for the 1996 Vanden Plas? Thanks.

 

Hi rendo,

Welcome to the Jaguar Forums!

Here's more than you probably ever wanted to know about ATF fluid:

If your car has the ZF 4HP24 electronically-controlled four-speed automatic gearbox, the original transmission fluid specified was Dexron III, and that's still the fluid recommended by ZF today.

In our '93, which has the 4HP24 transmission, I tried Dexron VI, which is supposedly backwards compatible for Dexron III applications. It wasn't until the next time I changed fluid, to Redline D4 ATF, that I realized the torque converter had not been fully locking up with the Dexron VI.

According to Redline Oil, their D4 ATF is the fluid they recommend for vehicles for which Dexron II/III was originally specified. It has a viscosity index of 198. Their D6 ATF, which they recommend as the equivalent of Dexron VI, has a viscosity index of just 166. My belief is that this viscosity difference may have something to do with the problems some owners experience after a fluid change.

The first time I changed the fluid to Redline D4 at the recommendation of a fellow Jag owner, I was amazed at how much better the torque converter locked up. I hadn't realized how much it was slipping before. It's most noticeable in Sport mode and when downshifting for engine braking when descending a hill.

It is telling to note that ZF does not state that its latest transmission fluids, LifeGuard 6 and 8, are backward compatible. Even more curious, for the older 4-speed gearboxes in our XJ40s and X300s, ZF still specifies Dexron III. They do not specify Dexron VI. To me, this strongly suggests that the gearbox manufacturer does not agree that newer fluids like Dexron VI will perform better, or even properly, in older equipment designed for Dexron III. See pages 2 and 3 of the document at the link below for ZF's recommendations for each gearbox range:

http://www.zf.com/na/content/media/u...omendation.pdf


It's important to remember that more than half of the fluid in the gearbox is retained in the torque converter and does not drain out when you remove the drain plug from the pan. Only about 4 quarts will drain from the pan, leaving another 4-5 quarts in the torque converter, so you have to do multiple fluid drain/refill cycles to replace most of the old fluid. Drain the pan, refill the system with fresh fluid and drive for 20 miles or so; repeat; drain the pan a third time, remove the pan and replace the filter, clean the pan and reinstall it with a new gasket and refill the fluid gradually until the fluid level after a long drive is exactly at the HOT line on the dip stick. The level is important, and overfilling can cause problems just as underfilling can.

Other transmission fluids may be just as good as the Redline D4, but since a fellow XJ40 owner recommended it years ago it's the only fluid I've been willing to spend money on for our car. I'll be curious to hear from others. Here's the link:

Red Line Synthetic Oil - Automatic Transmission Fluids - D4 ATF


The transmission filter and pan gasket kits are inexpensive and commonly available from the good independent Jag specialists and even your local chain auto parts stores.

Also, since we're a friendly bunch around here, please visit the https://www.jaguarforums.com/forum/n...-intro-must-5/ and post an introduction so we can give you a proper welcome and learn something about you and your Jag.

Cheers,

Don

 

Thanks very much Don. This forum is truly the greatest. Merry Christmas.