Hi Lads,

So I just recently bought this XK8 with 120k on the clock.

It wasn't readily apparent when I did the short test drive with the car but I have since discovered an anomaly in the way the car downshifts. In short, it seems to be lazy dropping to first gear.

It seems to upshift perfectly with no surging, slipping or any other weirdness but as I approach a stop sign or stop light, the transmission more or less "drops" into first at the last second. There is a definite bump that can be felt when it does this. I have tried approaching quickly and slowly to see if there is a difference and there doesn't appear to be any. You roll up slowly to a stop and at the last second (less than 5MPH) the trans drops to first and there is that little lurch or bump as it drops into first gear. From then, it shifts perfectly up through the gears.

Does not appear to be temperature related either. Car can be cold or hot and it does the same thing consistently.

I bought the car recently and I am already collecting the parts to a do a proper transmission fluid and filter change. With 120k on the clock, I am hoping that the fluid has never been serviced and that's all it is going to be. However, I also understand issues with valve bodies and speed sensors too as I just went through all of this on an early version of the new beetle.

I wanted to get some feedback as I don't want to waste brand new fluid with a fingers crossed exercise if I can understand what could be causing this. If the valve body (shift solenoids) need to be serviced, might as well handle that once everything has been taken apart.

Hope you guys can help?

Bernie

 

I would do an ATF drain-and-fill as an initial approach. If you're running the original factory fill of Lifeguard 6, the friction modifiers in that fluid have long ago worn out. Your fluid could also be low....

Plenty of threads here on changing the ATF in these ZF 6HP26 transmissions. We did my wife's 2006 XK8 at just over 67,000 miles in July 2013 (using nearly 6 litres of fresh Lifeguard 6 ATF, a new pan, and a new sleeve) . That, along with having the ZF Drive Cycle Adaptation procedure done at a Jaguar dealership, fixed her shift quality issues....

We did my 2005 S-Type at nearly 85,000 miles in November 2014 and again at just over 90,000 miles in October 2015 (using nearly 4 quarts of fresh Mercon SP ATF each time). The reason we did it twice was because unlike the ZF in my wife's XK8, the ZF in my S-Type only drained about 4 quarts. Same thing happened at the second drain-and-fill. No pan change or sleeve change either time, and that may have been why only 4 quarts came out of it. Now, most of the ATF in my S-Type's ZF is Mercon SP and it performs flawlessly....

 

Yelp, change the fluid first, see here for great info and specifically post #35 for a link to my tips.
https://www.jaguarforums.com/forum/x...03-xkr-147016/

 

Classic 'Lurch' symptoms as seen on the 2003 and up S-types. There's a software patch that may/may not be applicable and effective on your XK.

 

Hi Bernie,

The MERCON SP thread that James referenced is mine. I had your exact symptoms, and then some (actually - "many"). Properly servicing (I underscore properly - do it right) with MERCON made all the problems go away, or at least reduced them to insignificance. The kick-in-the-back-while-stopping is gone completely.

In the meantime, I believe your first gears woes can be mitigated by just pressing the sport button. Give it a try - you might like it. It only costs you a couple of MPGs around town; nothing on the highway.

BTW: She's gone 16,000 miles since servicing with MERCON SP. OPS Normal. Running GREAT! All anomalies are gone except a slight surging when cold, but even that's soooo much better than it was before. LUV IT!

 

What is the SLEEVE?

 

Thank You!

I watched the whole sorted affair.....lol.
Little nervous on the stripping out of screws but all-in-all it looks pretty straight forward.

Do you swear by the MERCON SP transmission fluid?
Being that it is much cheaper than the the ZF fluid, I was thinking that I could change the fluid and filter, run the car for a week or so and then change just the fluid again to clean out the torque converter.

B

 

I only changed the fluid, did not bother with removing the pan and filter and just the fluid change made all the difference and YES Mercon SP is the best way to go. Check with your Ford dealer, they stock it and it's cheap.

 

Cool!

They have it at O'Reillys for just 7.49 a quart.
Looking forward to getting this done.

Thanks!

 

Keep in mind that these transmissions, the filter is integrated into the pan, so in order to change the filter, you'll be ordering a pan. If it hasn't been changed yet, most likely it'll have the smaller torx bolts, I believe you need a T27 to remove them, but they can be a bit tricky to remove, they round out in the center.


The misconception a lot of people get with the " filled for life " is that it's NOT for the life of the car, it's for the life of the WARRANTY. Always always change the fluid, filter, etc, even if it's still in warranty.

 

What is this SLEEVE I see mentioned here?

 

Thanks everyone.

I found a OEM, ZF Transmission filter on ebay shipped for 100.00 so good deal there.
Will pick up the transmission fluid at the local O'Reilly's. They have to order it in but will be there within 24 hours or less.

So what is the total capacity of the transmission and how much fluid will be needed to do the change?

I figure it would be best to change the fluid cold as that will have the most fluid possible drained into the bottom yes?

 

System capacity in the ZF 6HP26 is 10 litres. Most folks are able to drain right at 6 litres if you drop the pan. By allowing the system to sit and drain overnight, some owners have managed to get right at 7 litres out of it....

 

Connector sleeve.

 

Perfect!

I will pick up 8 quarts to be sure.

Bernie

 

Hi Bernie!

Just to be sure, and because the SP is affordable, start with 7 quarts. Having a quart left over is better than finding you need more during the initial fillings. You're dead in the water then.

A few things to remember:

Before you begin to put the new fluid in, make sure the entire tranny has cooled (not just the pan). The first time I did this, I just waited till the pan was cool. As soon as the fluid hit the hot internals it went over temperature and I had to start over. It takes a few hours to get the tranny temp down from its normal driving temp. I just let it continue to drain during the wait.

Cycle the shift lever a couple of times immediately after starting the engine and then get underneath to put in more fluid. I cycled the gears and added fluid twice before it started to expand its way back out.

Be prepared to get the plug in as soon as the fluid hits the lower temp threshold. Practice how you're going to do this. The exhaust pipe will be hot. Have the plug and tools right at your finger tips. If you fumble this for too long the temp will go high (it does so rather quickly too); you will lose too much fluid; and you'll have to abandon the project until the transmission cools down again.

I used a laser temperature sensor on the outside of the pan. My thinking was: The fluid on the inside will be just a hair hotter, so when the pan temp hit the lower limit, I immediately plugged it. I then knew the fluid was "in range".


Good luck, PM me if you want. I'll give you a phone#


BTW: I've only changed the fluid once. It's an experiment to evaluate MERCON SP, for which I have absolutely NO complaints. My next update to the Thread (at 20K miles) will be soon. I'll do another refill some time in the next year or so, and then be "done" for the next 70 (or so) thousand miles.

 

The refill procedure goes so much smoother with two people. One guy underneath the car pumping in the ATF and one guy in the drivers seat doing the necessary gearshift cycling. So if you have a buddy willing to help, grab him....

 

Thanks a lot!

I actually have a temp probe for my multimeter which I used to do my VW bug. I just need to make certain it actually gets into the fluid when checking. I also have an infrared temp gun so if I can't get the probe correctly positioned I can easily default to the method you used.

It looks like having a second person during the filling is the best option to correctly monitor the temp during filling. Based on the video, it looks pretty straight forward at that point. Have the leather gloves and tools ready to plug the pan - copy that.

Still a little anxious about the possibility of the pan bolt heads stripping out. So I will soak things down with PB Blaster and let it sit overnight before attempting to pull the bolts. I think if I can find a deal on the upgraded bolts with the larger Torx head, I will replace them all when I do this.

Appreciate all the help fellas.

 

Here is what I did: I used a chisel/hammer to make a notch on the bolt head (metal is pretty soft, so no need to go medieval on it). It protrudes enough off of the plastic pan to do that. One you have a small notch, rotate the chisel some and hammer the notch so that it frees the bolt from any corrosion. I ended up having to do this on 6 different bolts. I then understood better why my trans filter kit came with spare bolts...

Others have recommended using an impact wrench, arguing the impact can free to corrosion better than torque alone. I have not tested this technique.

Also, this is probably one of those times where a better quality bit will make a difference.

This is not terribly difficult, just a bit frustrating and time consuming.

Best of luck, keep us posted.

 

Hi Lads,

So I finally got to the transmission fluid change and it wasn't without some hassle.

I ended up having 5 x T27 bolts that gave me trouble. I was able to get 4 of them to come out using a chisel and mallet but one was stuck pretty good and I had to use a combination of easy out and chisel and mallet to get it moving. Needless to say there are 21 x T40 bolts on the new transmission oil pan.

The rest of the procedure is not that bad. The transmission really doesn't warm up that quickly so I didn't have any panic moments where I needed to move fast. When my temp gun was showing 40C on the pan, I buttoned it up.

Initially, the tranny still bumped into first gear when I would crawl to a stop but after about 10-15 minutes of driving, the condition started going away. It is still slightly there now but only about 20% of what it was before I started so I am happy with the results so far. Since I only got about 5 liters of fluid into the transmission and it holds 10 liters total, I figure I will drive the car for a couple of hundred miles and then replace the diluted old fluid again. That should get me to about 75% of a complete fluid change.

I really only have 2 tips to add to the already well done writeups here on the forum. The first is make certain that you address every single T27 and the fill plug before you drain the fluid. It's better to know that everything is going to come off before you can't drive the car anymore.

The second tip comes from the fluid pump that most of us will end up using. To be sure that I didn't accidentally knock over one of the fluid bottles while I was filling the system and also to allow me to move more quickly if I needed to, I taped 3 bottles of fluid together at a time. That way it would be much harder to tip the bottles over by accident.

Good luck to those that want to do this by themselves. Its not super difficult if you are capable of dealing with those T27 bolts. I dusted all the new bolts with antiseize compound to protect them from the elements and to make sure there was a little lube on them for the next time.