I just aquired a 95 xj6 4.0L. While driving home yesterday from Tomahawk to Madison, and taking backroads as I got closer to home it seemed that the transmission would be hessitant to up shift to every gear. For example even under light acceleration it would not shift out of first gear until 30 mph, and would not shift out of second until 60 mph. Once the car was in third, and I would slow to just under 50mph it would downshift under decel back to second. Since this is my first Jaguar (and really one of the only automatic cars ive owned) I'm a little curious if this is normal?? The switch was in the normal driving position as well while this was going on. I have read that the mounts do go bad thus causing pull on the electrical plugs, causing issues. Could this be the case? Any help is greatly appreciated.

Thanks in advance!
Drew

 

My limited knowledge of this electronic trans is as follows.

The trans fluid is #1 on my list. If it has not been changed in your ownership, then simply undo the dipstick tube and let it run out (about 4ltrs) and then refill with Synthetic ATF. This has fixed many, many for me down here. You may be one of the lucky ones where the trans pan actually has a drain plug at the rear, most I see do not, so thru the filler tube fitting works just as well.

If that sorts it somewhat, then a proper drain, pan of, new filter, and refill will do wonders.

These transmissions are bullet proof by anyones standards, but do LUV fresh fluid regularly.

Electronic issues are rare, but not impossible.

Your symptoms reek of stale fluid, or LOW fluid to me.

You appear new, so welcome. If you have not done so yet, please intro yourself in teh "New members" area.

Your car is know as an X300, and tech questions in that area will get quicker responses, as not everyone comes in here that often.

 

+1 on every aspect of Grant's advice ... especially the lack of a pan floor drain plug ... I've never seen one. Do they exist?

I caught your New Member Intro ... and as it costs a fortune to keep all our red carpet in tip top condition, I thank you for making good use of it!

Cheers,
Ken

 

Thanks for the advice Grant, I did read in the owners manual to do a trans service every 30,000 miles. My grandfather did state that he doesn't recall the last time one was done. Since they moved north after retirement (roughly 8 years ago) the car had at most put 1500 miles on per year and even more recently about 500 per year.

I also did read in the owners manual that this car is equipped with the drain plug in the trans pan. I will get under the car tomorrow and see for myself. As far as fluid goes I did check to make sure it had some before I left the north woods and started my trek home but I did the foolish move of not checking it while hot, so that is also on the too do list. What brand of ATF do these cars favor and what should I make sure to stay away from?

I see a lot of people talking about the 4l80e GM trans being equipped in these vehicles. Is it a possibility that this is what I have?

Sorry for all the questions, I will be on here for a while seeking answers and advice, so get used to seeing me around

Thanks, Drew

 

Drew,

OK, the mud clears a tad.

YES, the distance is a spec that is stated, but a "time" is usually also stated, but not always. Much like "every 30000miles, or 2 years". All oils go "stale" over time, so I reckon some fresh in here will do wonders.

As for brands, well I will tread carefully here, coz I am down here. I use "Synthetic Automatic Transmission Fluid (Multi vehicle)". My choice of brands are Nulon, and Penrite.

The 4L80E transmission is fitted to the X300 XJR6, SuperCharged Rocket. The trans in ours is the 4HP22/24. The ....24 is the electronic unit behind the 4ltr engine. The ...22 is behind the 3.2ltr engine and is a non-electronic transmission. The USA did not get the sweet 3.2ltr, sadly.

 

Grant,

Totally understand the importance of fresh fluids and going stale as you say. It's just like you wouldn't drink milk that was 3 months old hahaha, so yes that would be one of the first on the to do list. Is a filter change necessary at these intervals or is it just a recommendation to change fluid? Me personally I would change both if I'm under the car but I know once transmissions get older they tend to "knock things loose" per say once they get a fresh fluid and filter. Sounds dumb I know but I've seen it in many dodges as well as some GM suv's.

As far as trans model goes I have the 4HP24. Is there anything I should know about this as sort of the do and don't do, or any little quirks they have about them?

I plan to do u - joints soon and possibly a trans output seal while the driveshaft is down. Anything else you would recommend replacing as preventative maintenance to ensure longevity and reliability?

Thanks, Drew

 

The filter in there is a Brass mesh thing, so can simply be washed out in MY opinion. Some other transmissions use a Dacron medium as the filter, and MUST be replaced regularly. However, blocked transmission filters in ALL my years is rare to none existent.

This I did on mine, once I dropped the pan. as you do when the car is first home, and noticed the mesh filter, but I installed the new one, since I had it. That filter is still in there, after 70K kms and 5 years. It has many, many fluid drop and refills over that time, and I dont have a drain plug. The transmission is now sooooooo smooth, and the shifts are barely detectable, as compared to when I first got it, when it was a tad harsh. The fluid was NOT grubby, slightly off colour, and just old.

The knock things loose is real, and that si why I do not flush auto trans units. I introduce new fluid, one drop and fill at a time. It will take about 8 drop and fills to get the new fluid concentration into the 90% range.

I would replace the tailshaft centre bearing whilst the shaft is out, makes sense to me.

Other preventative maintenance could be a long list, dependant on the mileage on the car in total.

Hoses, belts, power steer fluid, brake fluid, coolant, diff oil, are but a few that come to mind as first and foremost.

 

Hello again, Drew and Grant ...

May I butt in to suggest ... when you have the car up, or you under as case may be, use the opportunity to check sway bar bushes, linkages and suspension arm bushes and joints for wear. They will tend to wear in that order, and excessive play will often lead to bumps and groans that are otherwise annoying and sometimes difficult to track down in the early stages.

Cheers,
Ken

 

Thank you both again for the helpful advice, I will be going through the car thoroughly this weekend and making a list. I did notice that the front coil springs are a tad bowed and fortunately my grandfather just replaced the front left shock in December. I found a filter kit for the trans for 18$ US, which also comes with the pan gasket. Fluid I thought of using will be pentosin, a very high grade synthetic 17$ US per quart. I will check in my region forums with other folks to see what they have used as I know you are both in other countries and products vary. U joints seem to be a dealer only part so I would like to see if I can cross reference them to a Spicer product (very trusted in my industry and field of work and all we use)

Thank you both again for the words of wisdom and advice

Drew

 

Drew - I've moved your post from the General Tech section to the X300 where it will get greater visibility and response from the techs as well

regards,
steve

 

Hi Drew,

Welcome to the forum! I echo Grant's excellent advice about the transmission fluid change, and would add that since filters are so inexpensive (and often come in a kit with the pan gasket you will need anyway), I would strongly advise you to change the filter too.

Regarding the Pentosin fluid, I am aware of its high regard for many uses. The main thing you will want to confirm is that it is a proper replacement for the fluid originally specified by Jaguar for your ZF 4HP24 transmission. In the case of our '93 XJ40, which has the same gearbox, Jaguar specified Dexron II/III. The best currently-available fluid I know of to replace Dexron II/III is Redline D4 ATF, which I buy from Summit Racing for $46.00 per gallon (no affiliation with either company):

Red Line Synthetic Oil - Automatic Transmission Fluids - D4 ATF

I had been using a Valvoline synthetic ATF, but several years ago at the insistence of a friend at the Jag-Lovers forum, I tried the Redline, and the difference was amazing. Smooth gearshifts and excellent engine braking in Sport mode and when downshifting for significant declines, indicating excellent torque converter lock-up.

If the first 4-quart fluid change makes a noticeable difference for you, drive the car a while, then change the fluid again (I think the torque converter holds 5 quarts and that won't drain out via the pan drain or dipstick fitting). By changing the fluid at least twice, you'll renew more of the old fluid. Some guys even change it three times to be even more thorough. Summit Racing offers free shipping on orders over $100, so if you order two gallons of D4 and a small tool for your shop, you're there.

P.S. If you decide to do the two-time fluid change, don't change the filter until the second time. That way the new filter will only be exposed to fresher fluid.

Cheers,

Don

 

Thank you Don!
I have been very timid on certain fluids in my past experiences. My 91 240sx has a very soft metal in the syncros and using most 75-90 gear lube will destroy those because they are so soft. Most of that damage was caused by Royal Purple, although a good product for most applications, this was not the case and I payed the price haha. I'm greatful for the clarification and I will most likely do as you suggested and order the Redline ATF.

Thanks again!
Drew

 

I have no personal preference, but curious why one would choose the D4 over the D6 Redline ATF? I thought the upgrade/support path from Dexron II/III was Dexron VI, which D6 is compatible.

.

 

Hi Al,

That's a really good question, and I'm not qualified to give you a good technical answer. However, somewhere in my research I read that not all transmissions designed for Dexron III respond well to the lower viscosity of the "upgraded" Dexron versions because the valves and such were designed for a higher viscosity fluid. If you'll note on the Redline Oil website, they state about D6, "Our lowest viscosity...ATF..." Newer transmission fluids have lower viscosity to reduce drag and improve fuel economy, and newer transmissions are designed for these lower-viscosity oils.

The Valvoline Dexron VI full synthetic fluid that I used previously has a viscosity index of 155.

Redline D6 has a viscosity index of 166.

Redline D4 has a viscosity index of 198.

I think that may be at least part of the answer as to why the ZF 4HP24 in our Jag responded so well to D4. Perhaps we have a petrochemical engineer on the forum who can explain it!?!?

Cheers,

Don

 

Agreed will all I have read.

My opinion/experience, and YES,I live down here, and have a warped outlook on Jaguars, as in , they are ALL female, and I have had many, Jags that is.

When we enthusiastic folk get our Jaguar, it is a warm and fuzzy feeling, but the car needs "catch up maintenance", as we all know. The most neglected item/s on all the Jags I have aquired over the many years is the trans fluid, power steer fluid, brake fluid, coolant, in NO particular order.

Based on that, ANY fresh fluid, of ANY sort, in these components, will see outstanding improvements in performance.

I am not a "petrochemical whatever", just a lowly Jag nutter that has done ALL his own maintenance for a very long time, and observed lots of things, some good, some horrific.

Oils/fluids have all progressed greatly of late, and Synthetics have been a huge part of this.

The owners handbook specifies a certain grade/spec fluid for an application that relates to what was available in the year that book was printed, and the "updates" dont happen, of course. Hence the lube guides, and common sense.

Oil companies upgrade, as I said, and near all of these upgrades take into account the older specs, and make the updates MOSTLY backward compatible.

ZF here in Perth discussed with me on a truck Auto Trans I was involved with a while back, the use of Synthetic fluids in the 4HP series of units, and the end result was "use it, the trans will luv it". This I did on daughters '88 3.6 XJ40 (still rocking at 400000kms), and then years later on my X300 4HP unit, and that has now had 9 drop and refills (just finished one more this AM), and the noises, lurching, lack of retardation, clunky lock up, rough shifts are ALL gone. It is now at 210000kms, and unless you really get your brain attached, the shifts are undetectable, just the tacho dropping as it happens.

The TH400 in the XJ-S always had that "whine" in 1st gear and this was always considered "normal". Not now, it is silent, and Synthetic fluid has been in that for 10+ years.

Same goes for the OLD BW12 in Sir Arthur ('76 XJ12 PreHE), and that has topped 500000kms now, and still does what it does without fuss.

Here at work Synthetic oil/fluid sales now outstrip mineral in all applications.

 

Grant,

I couldn't agree more with you about the benefits of full synthetic oils. What I don't have a definitive answer for is whether the newer fluids are truly "backward compatible" for all applications. For example, is Dexron VI really a suitable replacement for Dexron III in every transmission?

One bit of info derived from my BMW maintenance is that ZF has, over the years, commissioned the development of fluids specifically designed for each new generation of transmission, beginning with the 5-speed models. I think I recall that Shell and perhaps Esso have been OEMs. LifeGuard 5 is the specified fluid for the 5-speed boxes (as in our E46 BMW), LifeGuard 6 for the 6-speeds (as in our X350), and LifeGuard 8 for certain other gearboxes (not necessarily 8-speed).

Curiously, ZF does not state that either LifeGuard 6 or 8 is backward compatible. Even more curious, for the older 4-speed gearboxes like those in our XJ40s and X300s, ZF still specifies Dexron III. Or maybe I should write that Dexron !!!

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


Still hoping to hear from a petrochemical engineer! :-)

Cheers,

Don

 

Take care with those front springs. They are a tad bowed as designed. The X300 does not have a serious issue with front or rear springs.

 

They do look pretty rusty and I'm sure they're original. If I can find em reasonably priced I might just do em anyway. Thanks!

 

As Grant states, the curvature in the front springs is intentional and part of the unique Jaguar suspension design. Removing and replacing them safely requires a special spring compressor, which you can make yourself. Below is a link to photos showing how I did it. Others have used a stack of heavy washers instead of the steel ball:

Welcome to Jag-lovers - Members Photo Viewing Page

If the rust on the springs is minor, with no significant pitting, you can just clean them and spray paint them - I wouldn't go to the trouble of replacing them unless you are also going to replace all the front suspension bushings (see my other photo albums for what that entails).

Cheers,

Don

 

Sorry I've been M.I.A. lately, work has been keeping me busy. Here's a little update while draining the trans fluid. As you see I am one of the lucky ones who have the drain plug (for all you non believers they do exist!) I am going to refill and head to work I will let you guys know how it shifts. And for reference I went with the red line synthetic D4, as per a recommendation from a fellow enthusiast on here. Sorry I don't have the name to give credit where credit it due haha. I'll post after my drive to work if I get it done in time.

Drew