OK. Today I finally took this on. For over a year I've had suspicions that both the German shop that did some tranny work for me a year and a half ago (and used Redline Fluid), AND subsequently a Jaguar dealer in Connecticut, both did not assess my fluid level correctly. Although the Redline fluid change did make one or two problems go away, the tranny just didn't shift nicely, especially going up into 5th gear. Recently, other shifting anomalies started to occur and I'd had enough with suspicions.

I bought 7 qts of SP at a fraction of the cost of other fluids and had the Ford parts guy confirm that this was what was called for in the 6HP26. BTW: 7 qts was a good call - this procedure can be a friggin' mess.

Anyway, on the drive home she did seem to be shifting better than ever (5th is still a bit off, but better). Tomorrow I'll see if I still have that morning surging problem, which had gotten worse in the last month. It was very noticeable, and quite embarrassing if I had some SYT in the car.

I'll update this post periodically with my experiences and satisfaction (or not) with the Mercon.

The idea that ZF built a special 6HP26 "just" for us, so different from the Ford unit that we have to pay FOUR times the amount for fluid is just idiotic . Sorry - I'm not that gullible. "BUT" if I'm wrong, and I toast my tranny, I "will" let you all know. And I've gotten 170,000 miles out of her, so a rebuild at this point wouldn't be out of the ordinary anyway.

BTW: I found a battery powered fluid pump that help speed getting the oil in before hitting 40 degrees C, but it was actually part of the messy bit too, because when you stopped pumping, all the fluid quickly ran backward down the hose and out the pump. After a couple of go-rounds I was able to compensate for this and minimize the spillage, but overall I probably put a good half a quart on the ground. This does not included the fluid running out of the tranny - most of which I caught.

Don't bother working around your exhaust pipes! (Friggin' ridiculous idea) Buy a set of exhaust gaskets ahead of time, disconnect the pipes and move the damn things out of the way. Especially when you try to remove the fill plug - what a PITA! - broke TWO 8mm six-point box ends, before I took the exhaust off and used a 3/8" breaker bar (WITH PIPE!) on an 8mm allen bit. The car is not that loud at idle with open pipes, the area will get a little hot from the gases, but access is now EASY and you won't burn yourself.

Stay tuned.

Ciao! - Jim

 

Did this & filter 1K miles ago, and no problem. Did the change again in 200-300 miles and tranny is much smoother and works great. Used a manual fluid pump with no problem. Left exhaust pipe connected due to bolts seized. 2nd change used about 5 1/2 qts. with fluid ONLY. You will be happy!

 

Rick, Wayne, and I did a ZF 6HP26 drain-and-fill on my S-Type last November using Mercon SP. No issues at all after approximately 5,000 miles since then. I'm planning to do it one more time before the end of 2015 to use up my remaining Mercon SP stash and to ensure mostly fresh ATF going forward. Hope it will be the last time I have to mess with this ZF during the car's remaining stay in my stable....

 

First Day Update:

What follows is a list of every transmission anomaly I've experienced, post Redline Fluid performance changes and post Mercon SP Fluid performance changes.

One: The morning drive to work surging is almost completely gone. This steadily worsened with the Redline Fluid and was bad enough that I could actually see the tach needle bouncing well in excess of 100rpm. This morning, with the Mercon, the needle never moved, although if I listened, I could still hear a slight amount of surging. Not bad. I'm happy. I may do another fluid service in a few months to clean out even more of the old stuff, just too make sure "that" isn't the actual cause. With the affordability of the Mercon, I can "afford" to experiment.

Two: The "kick-in-the-back" while rolling to a stop. This had been a real annoyance prior to the Redline fluid and I was afraid it might return with the Mercon. So far so good - smooth stops.

Three: There had been a "bloop" sound when shifting tofourth. This disappeared with the Redline and still seems to be gone with the Mercon.

Four: Very hard upshift when rounding a corner, say from a rolling stop or slowing to yield. This persisted with the Redline and may have worsened. It may be all but gone now, after the Mercon. Standby - I need to play some more.

Five: Very sloppy upshift to fifth gear. Revs would momentarily spike and then the tranny would abruptly drop into gear. I don’t remember this before the Redline fluid was installed; it was really bad right afterward. It got a little better over time, but never went away. There is still a bit of this activity after switching to Mercon, but it is much, much better.

Six: On-again/off-again stepdown shifts with throttle application. After Redline it seemed there were times when the tranny didn’t shift when it should have, and others when it seemed I was in a lower gear when it was really unnecessary. Putting my foot down for a pass was like betting on "Red" at the Roulette Wheel. Standby for analysis of Mercon with respect this.

Keep in mind, that despite my comparisons of the Mercon to the Redline, my real suspicion has always been that the fluid level was incorrect. The analysis of Mercon is primarily to provide a real world commentary on the most affordable transmission fluid there is for us to use. Why should we get played as suckers and fools? I'll risk my 170,000 mile transmission for the cause. If Mercon SP doesn't grenade "mine", AND the performance is improved, then those of you with much newer trannies will have no problems.

 

mine was having the hard shifts out of first but over the summer it has stopped upon driving it on a regular basis. I just hit 100k so maybe I will have a fluid change done in the coming months.

 

So, was the level under or over from what you found when replacing the fluid? How much did you actually put back in?


If you changed the filter too, did you notice much metal shavings in the pan?

 

I didn't recover the drained fluid, so I can't confirm what was in there. I just wanted to put in some fresh fluid, make sure it was at the correct level, and try out the Mercon. However, I did catch some of the old fluid to do an analysis on. Need to send it in yet though. I hope that if the level "was" low, there's been no damage.

 

Day two:

Every aspect of the transmission is even better. The slip-n-grab shifts to 5th gear are almost gone. Kick-down shifts for acceleration are wonderful - spot on and predictable. I guess it's in its learning mode again, because it was better today than yesterday. This went on for a while after servicing with Redline too, but that time there were a few pretty significant problems to smooth over, some of which never went completely away, and shifting was always noticeable.

Driving the car is very spooky now. The absence of all those shifting sensations is even more noticeable than the sensations were themselves! - lol. This time the learning mode is starting off from a point of vastly improved performance. If it gets much better than it is, shifting will be almost seamless. Very, very spooky.

I won't be able to update this for a while because I've parked the car for some front suspension work. But that's OK. Obviously, when serviced to the proper level with Mercon SP, the transmission performs wonderfully. Now we just need some long term testing, so I'll probably add an update in a thousand miles or so.

"Serviced for Life", my asp.

Sorry - there is ALWAYS room for preventative maintenance. There have been posts in here that have found some recommendations for fluid (and maybe filter) changes every 70,000 miles. I believe that is a really good interval. With the affordability of Mercon, a fluid drain every 50K with a new filter on the 100s is not an unrealistic possibility either.

 

Hello Jim,

Did this on my wife's XKR last winter and it is tedious, but not too bad. As far as the exhaust goes, no need to remove pipes. I picked up a heat shield blanket for welding and cut it into different lengths and wrapped it around the exhaust pipes with SS safety wire. The blanket material is black and good to 1800 Deg F. It made it very comfortable as I knew I would grab a pipe or knock my head into it! It kept the area very comfortable and no burning of appendages! Hope this helps someone who is going to change trans fluid in the future. The blanket material is very soft and pliable and can be reused quite awhile.

Mike

 

Depending upon one's level of dexterity when wearing gloves, a fireplace glove worn on the hand and arm reaching over the exhaust pipe may also do the trick....

 

Oops. I should have mentioned that I have a custom 2 1/2" HP exhaust system and separating the pipe from the cat is really easy (I don't even have a gasket to replace - sweet!). Once the fill plug was loosened it "was" possible for me to do the task even with the larger pipes in place, but the difference in flat-out ease of access once they were moved was nothing short of heavenly. "And" with the pipe moved I was able to get a torque wrench up there and apply the correct tightening torque (35 N-m). That made me feel good. I'm not sure how much narrower the stock pipes are. Maybe access is much easier with the OEM set-up.

There was no way I'd have been able to break the plug free with the pipe in place. I "had" to get a stout allen bit on a breaker bar and use a pipe extension as well.

 

This is very helpful....i also just hired a shop to do the fluid change and they uses Redline and I am not sure if I like the way it shifts .... I will probably get some Mercon Sp and do it myself this time.

 

Thanks for this - haven't done a fluid change to this car yet, but it was enough of a PITA on my XK8 that I might cop out and have my local guy do it. Trick is making sure they know to bring the tranny temp up to the right point before attempting the change. I get a bit of a surge right before second gear when taking off from a dead stop. Not sure this is a fluid problem but at 60k it might be worth a try.

 

Thanks for the Mercon SP info....doing my 03 in a couple weeks. Even on Maui the Mercon SP is only $7.07 a qt at the Ford dealer........

 

A month into the MERCON SP trial and I can report that:

I LOVE MY TRANSMISSION AGAIN!!!!

ALL shifts are smoother, even that annoying rev-and-dump into 5th. None of the previous anomalies have returned (i.e., the kick in back while rolling to a stop, etc.). Even the morning drive-to-work RPM surging is much better.

Some morning surging does remain though, and I'm wondering if another drain and refill (cleaning out even more of the old fluid) might make a difference? It's usually worst during the winter. I'll wait the season out and see; maybe I'll refresh the fluid after that.

I do not think I would ever trust a shop or dealer to do this service again. I must believe that at least part (if not most) of the dramatic improvements to my transmission's performance have come from the fact that "I" did the service and know for a fact that the temperatures were spot-on.

BTW: You must wait for the transmission "CASE" to cool down before adding the new fluid, or as soon as you start the car up, the fluid will circulate into the still hot case and it will be over 50 degrees in a heartbeat. It took hours for the case (not just the filter) to cool down enough for me to start refilling. I used a laser thermometer to measure the case and filter temps. I added fluid twice (maybe three times) after start-up; cycling the shift lever a couple of times each. I replaced the plug as soon as the temp went over 40 degrees on outside of the filter.

BURG: I gotta tell ya, buddy: I doubt that I will ever again trust a shop or dealer to do this correctly (unless I was standing right there directing the action AND taking the temperature measurements).

Ciao Y'awl

 

Very interesting discussion especially since I changed my 2005 XJR trans oil, pan and sleeve a few weeks ago.

I read lots of comments in this forum about what oil to use and finally went with the original Lifeguard 6 at $239 for 12 quarts. I also did a complete flush getting just over 10 quarts out and putting in the same amount. I also changed the sleeve while I was at it. I figured that Lifeguard 6 had done pretty well for 103,000 miles for my transmission so why change. Doing it myself saved me big bucks compared to a dealer anyway plus I know I did things correctly.

 

Hi Jackra,

It kinda makes sense that the Lifeguard and the MERCON would be the most problem free given that they were the only fluids used in OEM transmissions. The Redline and Pentosin (and any other after market fluids) would be question marks.

BTW: Expensive though it may be, I think that was a pretty good price you got for the Lifeguard.

 

Its currently $205 plus shipping here: The CTSC - ZF Parts

I used a laser gun thermometer the way you did Jim. I also checked the fluid level one more time after driving about 20 miles with a couple WOT runs. I found I needed to add another 1-2 fluid ozs at 40 degrees C.

 

Hey Jackra,

Where in MD are you? I'm in Great Mills / California. Work on base, PAX River.

 

I might need to try SP in the XJ. The slam into first is annoying and I have to leave it sport to keep it from slamming at a stop. I didn't realize it was that much cheaper than Lifeguard. I found a case of 12 for $90.