Transmission Fluid Recommendations
 

So, I'm looking for recommendations on fluid to use when I replace my pan/filter over the Thanksgiving holiday and I'm still no closer to deciding what fluid to use.

I see the following four options:
JAG labeled
ZF / LifeGuard
Mercon SP
Castrol Multi-Import Vehicle ATF
Mobile1ATF

One person (Reverend Sam) used Mercon SP in his XJ (same tranny). I have not been able to get any update from him although I'm assuming he's had no problems.

Someone else (StrateLoss) used Castrol Multi-Import Vehicle ATF on his car (I believe a '04 X350), and I heard someone else used Mobile 1 ATF.

I have not gotten updates from any of these people, but from what I've read from past threads, everyone has had good performance and no problems/issues.

Let me say that I'm not a purist; I just changed the front hood (bonnet) struts and got 3rd party for about $50 instead of the Jag-labeled ones at $120. I don't put Jag oil in my engine, and my brake pads are Akebono (hardly English).

So I'm looking for comments from anyone that has used any of these, and in particular, if there were any issues/problems (feel of shifts not as good/crisp, seals starting to leak, catastrophic failure because the new fluid just ate through the tranny, etc.).

I certainly understand if there is some metals in the transmission that react differently to different fluids (don't dump gas into your master brake cylinder (I was 21 and learned not to do it again, no fire, just ruined it), etc.). Also, new ATF have got to be better than what was developed back in 2005. Still, if there is something in that tranny that dies if something other than ZF or Jag fluid is used, I'd like to know.

BTW, even though the tranny in our X350s is the same as what is in a Lincoln Navigator (big SUV), the fluid is different, and someone said the tranny is programmed to different fluids so you'll muck up the same transmission if you put in different fluid because it doesn't match the fluid. I find that far fetched; can someone tell me exactly what goes bad if you do that?

Anyway, enough babbling, I need to get some fluid, and if I have to mail order it, I have to do it now so I get it before Thanksgiving. So any and all feedback is welcome (I have a flame suit on...... :)

Thanks in advance.


rather than the Jag or ZF / LifeGuard

There are soooo many threads on transmissions and problems and using the wrong fluid it did not even occur to me to experiment there.

I got the pan/filter and ZF/Lifeguard fluid from the CTSC ( The CTSC - ZF Parts ). I did this job a few weeks ago and so far so good.

I agree. This is one item you don't want to experiment with. Your (only) choice is the Jag fluid or the Lifegard 6.

I have heard of some using Pentosin...with good results short term, but no long term information. I have heard bad results from the Mobile one and Mercon. They are not bad fluids, they just have different properties than you need.

I don't want to start an argument, but just share my info to you: I used Mercon SP to replace my transmission fluid, and it is running very well. Compare $7 to $20, and I am happy with it.

What model transmission do we have? I know I have it written down somewhere on my computer but can't find it for the life of me.

Also, any problems removing the pan bolts? I've heard some people have had big problems.

I haven't seen threads on people using different fluids and then having problems but maybe I didn't look enough.

Thanks for the info.

Gordon

Yeah, the problem is no long term results from anyone (which makes sense based on the age of our cars). My '97 went 247k miles with one filter/pan change in all of those miles, and the tranny was still running just like new. Of course, a different beast, but I heard the tranny problems were more or less resolved by the '05 model year (which is why I bought an '05). I just hate hype over fact, and we just don't have the history.... :(

Did you flush the whole thing or just replace the pan and the amount drained by the pan? Maybe a mix is okay? How long ago did you do it?

Thanks,

Removing the pan bolts was not a problem. However, do not use any air tools. Use a ratchet and do yourself a favor and use a high quality torx bit. Take your time too and do not rush.

When you get the kit, do order the upgraded pan bolts. They have a larger head profilx and a larger torx bit is needed to install them. It will be well worth your money.

I did not do a flush. Simply drain, and following the instructions that are posted in this forum, fill the tranny with about 5.5 liters of ZF / Lifeguard fluid. The fill bolt on the side of the tranny takes a 6mm hex bit.

I have some pictures here: https://www.jaguarforums.com/forum/x...eekend-104279/

I did not flush the fluid but only drained and replaced the pan. I agreed with Lagonia that you don't need to use the air tool, hand ratchet is good for the job.

On the contrary, I am very interested in how it works out. Lots of owners ask about using other fluids, but almost none ever get back to us. How many miles have you gone since the change?

Gordon, with the '05 you should already have the large head bolts from the factory.

It has about 1,600 miles since I changed the fluid on October 13, I don't feel anything wrong so far, and actually the downshifting squawk noise between the gears in the past was gone.

I did it on October 13, and the transmission running well so far after 1600 miles. I guess it is OK to change the fluid without flush it. Lincoln Navigator (2005-2008?) used the same ZF 6HP26 transmission, and several other cars as well. You may find the information about this transmission on Wikipedia site. So I think it would be OK if we use the fluid which has correct formula to this transmission even they are under different name brands. That's my two cents thought.

I'm running on a much cheaper Ravenol 6HP - over a year, over 20 kkms, so far so good.

I have just changed the trans pan and fluid and had a major problem removing the bolts (set screws).

OK they have been there for 10 years but the main problem was the design of

the the screw. They had flat round heads about 3/4 inch dia. with a very small

torx T25 which was only 1/8 inch deep and of course every one I tried stripped.

I undid 6 with hammer and chisel then gave up because of lack of access since I was

using wheel ramps.

Took it to local Indy and he did it on his ramp (lift).

He did it using hammer and chisel too! but of course had better access.

The new set screws have bigger torx T45, but what is wrong with a hex head

anyway?? I am not such a fan of German engineering any more!

Tip-Ensure you can move every screw and the filler plug before you drain the fluid-

luckily I did that.

Next time will probably just change fluid.

You are describing the normal experience with the earlier "small" screw heads. They went ot bolts using a larger torx by 2005...for good reason!

Well, I'll make sure I have the larger T45 torx before I start. Next, I'll make sure I loosen the fill plug (6mm hex) before I start anything.

Thanks everyone. I'll let you know how it goes. :)

Very much interested in hearing your results too! I'm about to drop my pan for a fluid/sleeve change before Christmas travel. Good luck with your repair this week!

There are 2 sizes of TORX pan bolts, 27 (early) and 40 (later).
If you use a 25 you will strip the fastener.

The fill/level plug is 8mm hex (a 5/16" will work fine).

bob gauff

Thanks Bob. I think I'll roll it up on ramps and double check in case I need to buy anything. BTW, the filler is on the left side near the front of the tranny, correct? I thought I remember seeing something that looked like it, but that was a while ago. I'll dig out an 8mm or 5/16 hex wrench to see if it fits.

Thanks! Will let you know. Some people say it is a piece of cake (although lying under the car with the engine running and putting my hands near the exhaust pipe does not sound like a piece of cake or any fun whatsoever), and other say they strip out the pan bolts. Hoping for the former.... :)