ZF gearbox fluid & filter change

[peterjameswass]

A topic that has been covered many times on other forums!

I have a 2003 X350 XJ6 Sport which I purchased in April with 83k miles on the clock. I've added 10k miles to it since (and very nice they have been too!) and have read with interest the debate about whether (and when) it's a good idea to change the oil and filter in the 'sealed for life' ZF six-speed auto gearbox.

My local independent was of the opinion that it could do more harm than good but having trawled through the various comments from owners on other forums the consensus seems to be that a change of fluid and filter is generally considered 'a good thing' - with many comments that about 100k miles is the top-end of the expected 'life' of the gearbox with its original fluid.

Not wishing to be faced with a gearbox going bang any time soon, yesterday I contacted Tom at TL Jaguar for a second opinion and whilst he obviously couldn't be definitive about the likely outcome for my particular car his opinion was that it would be worthwhile.

So I have booked it in to be done on 4th November - expected cost circa £300 + VAT for the fluid and filter change plus a reflash of the software - fingers crossed it's the right thing to do!

Has anyone here had the gearbox service done? Were you happy with the results? I'd be interested to know!

[J44EAG]

Many of us within the club have changed our gearbox oil in the light of experience gained over several years.

Oil has a finite life. When that is exceeded, the trouble starts and costs a couple of thousand pounds to fix.

My article in the November 2010 JEC magazine gives a fuller explanation of the problem.

Bristol Transmissions who on average recondition around 10 or 12 Jaguar gearboxes per week, suggest oil is best changed every two years or 24k miles to preserve long term gearbox longevity. The large number of Jaguars and other makes that require rebuild after gearbox oil break down gives some indication of the scale of the problem when oil changing is neglected.

The question is not that of if a gear box will fail if oil changing is neglected, but more of when the failure will occur. From my experience and that of many others is that failure will occur if a change of oil has not been carried out on a regular basis. If your gearbox is currently running well, I would suggest you change the oil to keep it functioning as it should. To ignore the issue is to invite problems to occur at some point in the future.

Mike. S-type Forum.

[robv12]

most definitly the correct thing to do, I had my 3.0 350 done at 112K, including a reflash of the ecu, cost was 380 squids at my main dealer, but worth every penny, transformed the car, slick changes, less of a "lurch" from a standing start, car is now at 130K and with a new owner, but he can kive safe in the knowledge that the box will be good to at least 200K

that said the ZF six speeder is a far superior unit to the old 308 unit, which went bang on a regular basis, and still does!!, I am aware of a number of 200K plus miles X350's running on the original gearbox

at the recent 350 JEC Seminar, David Marks made the point that they have only ever changed one X350 gearbox, yet 308/XK8 ZF boxes are in high demand even now

[barrywi]

The only thing to make sure of is that the change is done properly. It is not like an engine oil change and David Marks has spoken at the recent X-350 seminar of the correct process which is oil temperature sensitive. The bottom plate holds the filter which obviously should be changed at the same time as the oil and even though it is near on impossible to remove all of the old oil without a total strip down of the box, the consensus is that it is a good thing to do to ensure the longevity of the gearbox. Either use a jaguar dealer to do the job or someone who knows exactly what they are doing.

[peterjameswass]

Thanks for the comments - I'm glad they confirm that it's a sensible thing to get done.

TL Jaguar in Wokingham will be doing the work and from the various glowing recommendations on the forums and from speaking to Tom there yesterday it seems that he very much knows what's what when it comes to the ZF transmission and all things Jaguar.

[Montana5]

Either use a jaguar dealer to do the job or someone who knows exactly what they are doing.

Barry, I know you mean well by that statement, but with Jaguar's 'head in the sand' attitude towards servicing customers Auto Gearboxes, I'm afraid that sounds like a classic example of an oxymoron

Doug.

[barrywi]

I suppose my comment was just meant to protect the person having the gearbox oil changed. If they get it wrong at least ( in theory!!!) you would have a right to get them to sort it out, whereas if you did it yourself or got a mate to do it( who may actually know more than the Jag dealer) you would have no comeback.
Also David Marks said it was a two man job and you need a hoist to keep the car level during the process.
Please don't call me a "Poxy Moron", I may have to report you to the moderator........

[J44EAG]

If you lot have finished knocking spots off one and other!

By tradition, Main Dealers went with the Jaguar edict that oil changing was not necessary. Time, misery and costs have made the industry see things differently. A Main Dealer will take a car in for gearbox oil changing now, but few if any have full flush equipment in their service bays. It is not cheap kit at around £25k to purchase.

What usually happens is that the Main Dealers and many independents farm the work out to a local specialist gearbox reconditioning and service business who do much of this kind of work and can justify the purchase of the equipment as part of their standard everyday kit.

Just changing the oil in the gearbox and the filter is just a half way house measure. The specialist equipment by comparison also flushes the torque converter and oil cooler system ensuring that the vast majority of old oil and solid particulates are removed. Just changing the filter and gearbox oil alone cannot achieve the result of the full flush gear.

DIY oil service is not practicable or advisable. In fact trying to achieve this work flat on your back with the car on axle stands is almost impossible. At a specialist workshop, after an initial fill with new oil, the car is jacked with rear wheels off the ground. The transmission is then cycled through the gears and oil allowed to reach a specific temperature. If the oil exceeds that temperature at any point, it must be allowed to cool before the correct topping off with additional oil proceeds. Please don`t attempt this operation yourself. These modern gearboxes must be serviced correctly and without the specialist equipment and knowledge, disappointing results and danger of transmission damage may result.

Taking your car direct to a specialist will save you money and you will retain control of the work. Any third party handling the work on your behalf is likely to add a premium to the specialists figure for time spent handling your car.

Mike

[PaulGover]

FWIW, my old X308's 5-speed ZF box lasted 195,000 miles without problem, and only one oil change at 140,000 miles. I thought about a change at 100,000 miles, but that was when the perceived wisdom was "if it ain't broke don't fix it".

I suspect the longevity is affected by driving style, and in particular use of "sport" mode. A common cause of failure was reckoned to be a worn circlip/seat on one of the gear sets. My guess is that use of sport mode means you spend considerably greater percentage of the time not in top (which uses a clutch to "lock up" the transmission to a straight-through drive), and hence causes all the wiggly bits to spend their time spinning against one another, producing friction putting heat, shear and metal filings into the oil. I probably used sport mode less than 10 times in the 10 years we had the car.

[orme]

Hello all! My 1st post! Car is a 2007 x350 sov 3.0 with 57k and I admit to being a very fussy owner who worries about the smallest things that could be wrong! My question is should I have the g/box oil and filter change? I do get a slight 'jolt' when slowly/gently comong to a halt (say at traffic lights) then just before box changes down to 1st lights change to green and I (gently) apply power box slips down to 1st then 'snatches' second. Is this normal or have I 'induced' this by being too 'gentle with power? Also (possibly unrelated) I have noticed lately when driving off from cold I hear a noise (hard to describe) when changing up from 1st to 2nd/poss 3rd but ok in higher gears and not when warmed-up (2/3 mins driving in top) it's so difficult to know what to do as I intend keeping the car for at least another 2/3 years and do approx 11k/year. Also main dealer (Grange Brentwood) and highly repected indy (les Pauls) said to leave alone as could cause damage. Also very expensive! HELP PLEASE to make me decide one way or other! Thanks. Peter.

[J44EAG]

What you describe is known as "The Lurch". This is a well known six speed unit problem which can sometimes be cured by a software reflash update.

There is also an internet site named "The Lurch". It details an owners problem and makes interesting reading.

On gearboxes that are below about 75k miles and show gearbox oil that is clear, unburned and not showing evidence of clutch or gear train wear particulate, these boxes could have their oil changed without much fear of the new oil acting as a detergent and releasing trapped particulate. On gearboxes that show oil that is clouded by particulate, is black or otherwise degraded, then draining and filling with new oil may cause more problems than it solves. Oil that exhibits such contamination is indicative of the transmission being on its last legs and filling with new oil is unlikely to achieve much. The damage will have been done and no amount of filling with new oil will repair such damage.

In principle, ignoring oil changing is to invite trouble. Owners have learned to their cost that doing so will inevitably lead to a £2k rebuild cost. The decision to change or not to change oil really needs to be made taking into account age and value of the car together with the gearbox mileage covered and the condition of the oil when a sample is drained from the car for inspection.

Interestingly several weeks ago, one of the boat owners down here at the marina proudly showed me his rather high mileage and somewhat knocked about S-type R fitted with the Mercedes gearbox. Although different to the original 5R55N Ford unit and ZF six speed units fitted to the XK, X308, X350 and s-type non supercharged cars, the Merc box also suffers if oil changing has not been carried out at sensible intervals. The fellow was lucky. He complained of bad gear shift quality at a mileage of 125k. My suggestion was to take the car to Express Transmissions at Portsmouth (local to me here) and have them sample the oil and change if felt practicable to do so. So the chap took my advice and did just that. It transpired that his car was short of four litres of oil! Where that went is a mystery, but having had the gearbox then completely drained and refilled via a fully flush unit, he rang me to offer thanks. That doesn`t happen often, but it is good to know that oil servicing can prove to be very beneficial.

Further explanations for the wisdom of oil changing can be found in my article in the November 2010 issue of our club magazine.

Hope that helps.

Mike K

[orme]

Thankyou Mike. That helps!

Peter.

[barrywi]

Thanks from me also Mike for coming in so quickly with advice.
If you decide to go ahead with a change make sure it is done by someone who knows exactly what they are doing. According to David Marks one of our XJ experts it is a two man job, not particularly difficult, but there is a specific procedure to follow. The gearbox filter is attached to the bottom cover of the box so obviously it should be changed while the cover is off. The gearbox is usually left to drain overnight, but that does not remove ALL the oil. It is important to refill on level ground and not to allow the gearbox oil to get too warm. One man fills, the other operates the gear change to make sure the new oil gets into all sections of the box.
Let us know what you do.

[Spud23]

Autobox oil filter.
To make it clear to those who don't know, and yesterday I didn't, the oil filter is incorporated into the sump cover and you cannot get to clean/change that filter. The only way to get a new filter is to buy a new sump cover and I understand they are about £250. On the sump cover (oil side) are a couple of round magnets which also collect ferrous debris. These can be cleaned manually if you don't want to buy a new sump cover.
Thanks to West Riding Jaguar at Mirfield!

[ptjs1]

Kits that replace the sump (incl filter) + the 6 litres of expensive fluid are readily available at £185 inc VAT & delivery.

I even persuaded my Jaguar main dealer to fit the sump and fluid that I provided rather than purchase the items through them.

Hope that helps

Paul