I am getting ready to service my transmission on my 1999 XK8 which has 76000 miles, normally I would drop the pan change the filter clean magnets and refill with Jags ATF, but recently I am giving a lot of thought to doing the flush thru the transmission Line because you get more old fluid out the torque converter especially. I have done the drain drop and filter change and refill on a few of my other cars, but deep in my mind is you don’t get all the old fluid out. With the flush the old filter is still in and whatever is in the bottom of the pan. I am thinking about dropping the pan, change filter, drain what comes out and then flush the remaining fluid out and filling everything up. Anyone used the line flushing method or what are your thoughts on it. Dave in Tampa

 

I just replaced the pan and sleeve in my XJ8, along with a fluid change (9+ quarts changed). I am a proponent in changing via the cooler line for the reasons you listed-that is, it changes more fluid out. Plus it is less messy and saves time on the pan drop...but it sounds like you are dropping the pan anyways. Changing the mechatronic sleeve on the back of the trans is usually recommended, too, as it can start to leak and foul the plug causing faults. When I changed the sleeve the old one slipped right out and the new one was tight to go in, due to the thickness in the gaskets.

If you have the original plastic pan the filter is built in, which means you need a new pan if you want the filter changed. I converted to a metal pan with a separate filter so I can just change the filter down the road, but the plastic pans works just fine.

When I changed the XK8’s fluid last year (just over 100,000 miles on the original) I didn’t drop the pan or change the sleeve. The fluid was pretty grungy. The XJ’s fluid had under 90,000 miles and it was still pretty dirty, but the pan and magnets were fairly clean. Personally I don’t see a need to drop the pan to change the magnets and such, unless the pan gasket is leaking.

As a side note, once you drain the pan of the 5-6 quarts you won’t be able to flush via the cooler lines until the pan is filled back up. The cooler line going from the trans to the cooler will just pump air as it draws from the pan...I tried it on the XJ8.


Edit: Sorry, I just realized you have a 1999 with a different trans, I do not know how much of this applies.

 

Did you adjust the fluid level for this? I believe the fill procedure is different with the metal pan. I briefly considered doing this a while back (these pans come up on eBay, and metal is better than plastic and all that), but decided not to when I realized less fluid would actually be involved in the process...

 

Ha I’m still a bit bitter about that point as it took me a while to figure out their fill method was not right. But long story short yes I did initially adjust the level by using their fill method via the port at the bottom of the pan. After doing so it was pumping air through the cooler line at the their fill level because it was so low on fluid and the car would hardly move, along with throwing a transmission fault.

I ended up filling via the side port using the Jaguar/ZF fill procedure (adding another 4-5 quarts!) and the car shifts just fine now (actually it is better than before). I emailed CTSC requesting info on why they require the metal pan to be filled a certain way, but have not heard back from them.

Though I didn’t measure, if I didn’t know any better I would say the metal pan I installed held every bit as much as the plastic pan, if not more.

Here is the pan and seller I purchased from:

https://m.ebay.com/itm/ZF6HP26-Trans...=1941684497017

It says the pan is GFX Allomatic brand. CTSC’s metal pan is currently not available for unknown reasons, but theirs is the only instructions online I have seen in which they say to fill with less fluid. The only logical reason I can see that they would say not to overfill is because their pan uses one less liter of fluid, so they do not want the consumer to drain 10 quarts out of the plastic pan, and then refill with 10 quarts in the metal though it should be 9. It is virtually impossible to overfill these transmissions though, and the fill plug on the pan I bought was utterly iseless, so I am at a loss for any real logical reasoning.

My question I posed in another thread is, why would filling at the side fill plug be any different with a different shaped pan? The upper line or limit of fluid should be the most important aspect. The fill level should be consistent for transmission health regardless of how much oil is in the sump (within reason), unless my thinking is way off.

Here is my thread in the x350 forum if you want a chuckle:

https://www.jaguarforums.com/forum/x...-fault-196757/

 

We had a forum meeting at Mackie Automatic Transmissions in Glasgow, Scotland in 2014.

https://www.jaguarforums.com/forum/j...ssions-114845/

As well as providing a fascinating insight into transmission faults and overhaul, it made me a firm believer in drain-flush-refill with a filter change.

Graham

 

My other concern is if I just drop pan change filter and refill with Pensotin, Lifeguard 6. Or mercron sp, is the fluid left in the torque converter will still be there and I do not know what type it was, and all the fluids I might use say DONT mix with other fluids, so I am leaning toward the total flush and new approved ATF going in.

 

I did a filter change followed by three additional drain and fill, also a pressure valve upgrade on my 97, over the five years and 15K mi that I owned it. Used Castrol Euro and it was still going strong when I sold it.

 

I utilized the multiple drain-and-fill approach when converting our two ZF 6HP26 transmissions from LifeGuard 6 to Mercon SP several years ago. Both of them are performing quite well now. The 2005 S-Type is approaching 106,000 miles. The 2006 XK8 just passed 114,600 miles. Drain-and-fills are safer because they do not run the risk of dredging up long-settled pan debris and dragging it back through the valve bodies, creating problems that were not present before....