Clunk when shifting from 1st to 2nd

[garypmcclean]

A8 4.2 V8 Auto 2005 102K

I looking for some thoughts and suggestions.

I had all the discs and pads replaced on Wednesday and now the car has developed a clunk when moving off and changing from 1st to 2nd. It's also there when coming to a stop.

The car was back in the garage for a service today, I've spoken to them about this, they've confirmed nothing about the disc and pad replacement would cause this.

They connected the car to diagnostics and said a non specific gearbox fault was showing. They're suggested changing the gearbox fluid at a cost of £315, but can't be certain this will resolve the problem so I'm reluctant to get it done.

Has anyone else experience the same problem?

I noticed when the gearbox is in S mode and changes at higher revs there is no clunk.

Thanks in advance for any help.
Gary

[damtom85]

First step, change fluid I gearbox with proper ZF fluid, make sure oil is changed according to service instructions, also make sure that the garage will change the filter and clean magnets and they will do visual check once gearbox pan is removed.

102k fluid should be changed long time ago, ZF manufacturer recommends every 50k-70k miles. I think you should have ZF 6hp gearbox in your AUDI, if you do, then I can send service manual for this gearbox from ZF or you can find online then you can pass on to garage.

I wouldn't do that in AUDI garage as they don't do properly whole procedure. Find independent specialist who knows ZF gearboxes

Good luck

[garypmcclean]

Thanks for the info damtom85.

How can I confirm the gearbox is HP6? the gearbox code from label in boot is EYC HHV.

Can you recommend a good source to purchase proper ZF fluid?

Thanks in advance

[damtom85]

Hi, then your gearbox is ZF 6hp26. Fluid for gearbox is ZF lifeguard 6. You can buy them on eBay, at just over £20 per litre, ZF-LifeGuard Fluid 6
1 Litre (Part No: S671 090 255)
20 Litre (Part No:*S671 090 253)

I know you can buy other manufacturers oil but as shows thread on AUDI USA forum, it is not good idea and better not save pennies on this.

But I still recommend you to go to specialist where they do change fluid in ZF gearbox. They usually get barrels (205litres) and price of oil(fluid) might be even less than eBay.

[EG-4.0TDI]

Hi,

First thing is to check that the clonk isn't suspension or gearbox/differential mount related before you open the Pandora's gearbox of horrors. That said, the non specific gearbox fault code does imply gearbox trouble so, on that basis the first thing is to get the diagostic code interpreted - you never know your luck, it might be something simple.

Take it to a ZF specialist. There aren't many in the UK that are ZF approved, but if you ring ZF they will give you contact details over the phone (there are about five or six of them from recollection - PM me and I can give you details of the one I have experience of).

A few points in case they are helpful in shaping your thinking with regard to fluid and clonks:

(1) The filter is also the gearbox sump so it is a big lump of plastic. If you change the fluid without the filter, you end up leaving a lot of fluid in the filter which you can't get out. And the old filter is full of metal swarf from doing its job over the last 102k so is past its best.
(2) To do the job properly, you therefore need to change the filter as well
(3) Changing the filter on a D3 is a big job because it means dropping the sub frame to get access if I recall correctly - it is doable but adds quite a few hours of labour.
(4) The fluid level is extremely sensitive to temperature and requires diagnostic equipment and adaption programming in order to get the level right and then program the box afterwards - hence why it should go to a specialist to get it right.

Finally, at 102k, don't expect a fluid change to solve your problems - it might, but it probably won't. By this mileage, the clutch packs and the little rubber finger tip shock absorbers inside the box are quite worn which are, between them, usually what cause the commonly experienced clonks, hard shifts and hooting between 3rd and 4th. Just changing the fluid is unlikely to solve this. You might get lucky, but don't get your hopes up.

Be prepared for a gearbox rebuild - in which case you're looking at about £2000-2500 for a total ZF rebuild (ie total tear down and renew anything worn - excluding the mechatronic which is another £500 if you need that as well). Or about £4500 for a new box from Audi plus fitting which is about 16 hours of labour.

Hope you get it all sorted OK!

[MarkTM]

Appreciate that Audi says 'sealed for life' yet the tranny manufacturer recommends a fluid change before 80k miles and then every 40-50k

I had a 1st and 2nd 'clonk' and had a fluid/filter change on my car done and it went away completely, although it does take a few hundred miles of driving to be noticeable.

Things to ensure

A) That when they have the bottom off the tranny that they do the ZF bolt tightening sequence
B) That you are able to do the gearbox adaptation

I used an aftermarket fluid with no ill-effects, appreciate that there will be circa 2.75l of old fluid left in your torque convertor, so your fluid will only really be 70% new.

ZF Lifeguard 6, Shell M 1375.4,Transmission Fluid, ATF,

In fact it was the same people that did my change and think it was £270 with aftermarket fluids and filters, £370 with LG6 and Audi filter. LG6 from them is less than £16 per liter.

20k miles later and no issues whatsoever

[garypmcclean]

Hi

Thanks for taking the time to reply, I appreciate the info.

Regards