While in Ohio a few weeks ago, the car developed another condition...when shifting from neutral or park to reverse and sometimes drive, there is a dull but harsh thud felt through the whole car, the rear end also squats a bit.

Few thousand miles latter and it is still doing it. Local dealer suggested a TCM reflash and if that's not it wait until the transmission fails completely.

Anyone encounter something like this?

 

Really ! Wait till it fails then we can put a new tranny on for you for $10,000 !! I am fairly certain the TCM reflash will cure the problem, but if it was me I would want a second opinion, (bit like when the doctor says you need open heart surgery). Any decent independent shop near you ?

You don't mention any fault lights at all; normally thuds and thumps like this are picked up by the fault watchdog software. If everything else is AOK, then I would not think the transmission is close to failure, its more lie a sticky valve. Might be worth a fluid change.

 

Mine does it now & then too. A real loud bang from park into gear & vice-versa.

To me it's a gentle reminder that the tranny has done >90'000miles & probably on it's original oil, & that I need to get it flushed & changed next payday.

My old mate Thomas (of 250'000mile S-Type fame) told me that his did the same, had the tranny fluid changed & TCM re-flashed, it was like a new car.

Don't believe them when they say "sealed for life" that's a load of bull.

 

IDS shows nothing. It is almost at 89000 miles. Too many veterans have advised against a fluid change insisting the OE fluid is so good, it should last. For the moment I am deferring to this advice considering the source.

Couple of points to emphasize, it is more frequent and harsher shifting to reverse rather than drive. It does not do it all of the time and is more frequent after about 30+ minutes of driving, though that could be coincidence. It has NEVER done it before. It started after non-stop 1,000 mile drive. There is a bit of brief groan & vibration only while it is thudding.

I am not opposed to a reflash but hate to spend $300 for a shot in the dark. I am going to talk to an old transmission shop tomorrow and see their thoughts, if any.

Unless I am misinformed, if it is an adaptation issue, after an additional 2,000 miles of driving consistent speeds with adaptive cruise control and little brake use wouldn't it have adapted itself away?

I have about 11,000 miles of warranty left and don't want to miss out if it is an issue that can be covered.

Thanks all for your suggestions!

 

Well I'm a veteran and I say that fluid should have been changed out at 50 k miles. I'm just saying----.

Moreover, that Jag specialist you visited in Indiana is a strong proponent of this, if I'm not mistaken.

 

Actually he is one of the techs who talked me out of it.

 

The warranty throws a cat amongst the pidgeons...I can understand you want to protect it, however...

- You already took the car to the dealer, they said they wouldn't do anything except a TCM reflash, work which I suppose is not covered under the warranty.

- These transmissions don't really "fail completely" they will just drive poorer & poorer until you can't stand it any longer.

Either way it seems your warranty isn't going to cover getting your concern sorted out. In the meantime the tranny is choking on old fluid, and when your warranty is long-gone, you'll be left with a worn-out transmission, and the bill to sort it out...

Have they at least checked the fluid level to make sure it's full?

If you look at other manufacturers that use the ZF 6HP26, i.e. BMW, Audi, Ford Australia, etc they all have changing the fluid in the service schedule at some point. Sealed for life is bull...

ZF will sell you a replacement pan/filter & gasket, and their own recommended fluid. In fact Thomas' had the fluid changed at a Jaguar dealer, but he knows the Service Manager & Workshop Supervisor personally, and they could negotiate the price...

 

Ooops. I had him confused with some body else.
I still think it a good idea to change out that fluid. You can flush it out short of a complete filter/fluid replacement. Come on over to AllJag in Orlando. They will do it while you wait for reasonable cost. You may thank me later.

 

I would check out universal joints also.

 

https://www.jaguarforums.com/forum/s...on-sale-44570/

The S-Type has the same tranny...seems to be a lot of positive feedback about oil changes...?

 

I certainly had every intention of doing a transmission flush. Several people advised against it but it seemed there were many who had success with 6HP26 flushes in other vehicles so I was ready to go, but I encountered a few hurdles finding a shop that could do it and the closest Jag dealer would only use BG fluid. Finally I found a reputable transmission shop that had been around for 30 years and they advised against touching a perfectly sealed, functioning, leak free transmission filled with OE fluid and indicated the ZF fluid should never need changing unless their was a failure. I also spoke with a veteran Jaguar master tech who also insisted the ZF fluid was so well engineered, it should be left alone.

While I am no expert, the more time I spend experiencing the thud and its side effects it feels like something is either sticking or lose and it seems to get worse the hotter the motor gets. Considering the somewhat inconsistent nature I don't feel confident it is a software issue.

I am also perplexed how it went from non-existent to full time in one day.

 

After monitoring the thump, here is more info on what I have observed.

It only does it when the car has warmed up

It does not do it every day, regardless of drive duration

It does not do it every time, even after warmed up, sometimes it will thump 10 times in a row, then not thump 2-3 times in a row

The intensity of the thump is not consistent, sometimes it is somewhat "mild" sometimes it is very "harsh".

Wouldn't an adaptation issue we more consistent than this?

If not, then I will go ahead and spend the money to reflash the TCM and hope for the best.

 

Ah i'd forgotten about this thread...
I cleared adaptations & reflashed my tranny about a week ago, and it hasn't thumped or banged since.

Fluid change is still on the cards for me though.

 

Well Jeremy, you are applying logic to an illogical world. Remember, you are talking about a transmission that can stop upshifting if the front tires have a small difference in circumference. Sounds crazy, until you find out how much "stuff" is taken into account before the electronics makes a final decision how to operate the thing. So much that it occasionally "learns" some bad things, maybe weird things. Adaption clearing is the only way out.
[Sometimes even I wish we could go back to carburetors and detent cables] Well, that is until I sit in the XJR and put my foot down.

I know it's more money, but it may put you at ease.

BTW--The guy with the red fluid..........stay away!

Cheers,

 

Me too, sometimes By the way, the guy with the red fluid, that's our friends at the closest Jag dealer here...

 

I guess it does make some sense, if something were amiss, the diagnostics are so sophisticated, IDS should pick up on it, right?

Besides starting with a cold transmission, any other requirements to perform a proper reflash?