Passat B5 Automatic Gearbox Problem

[Hogman]

Hi All,

Just joined the forum and hoped that someone may be able to help me.

I have a 2002 1.9TDI 130BHP Passat Estate, with Automatic Tiptronic Gearbox.

Engages gears fine, changes gears fine, so significant delays or thumps or clunks on engaging gears, but......

If i am cruising along, probably in top although not necessarily, and lift off the accelerator so that the car is just into overrun, when i then put my foot back on the accelerator and press gently, the revs climb a few hundred rpm without any increase in road speed. After a couple of seconds, the revs then drop back down and the road speed increases.

The effect is similar to what would happen if you had a slipping clutch on a manual gearbox.

Yet if i am cruising along, and then i actively put my foot down as i go up an incline, obviously without the car changing down a gear, it takes up drive fine with no apparent slippage.

Additionally, the 'clutch slip' is less pronounced if the car is driving in tiptronic mode!

It is almost as if during the overrun phase, the gearbox is thinking that it should change down, so that it starts to disengage the drive, and then on reapplying the accelerator, the gearbox has to then re-engage drive, giving rise to the 'clutch slip'.

The car has done 180,000 miles, and to my knowledge, the gearbox oil has never been changed, since VW don't suggest a service interval for this.

Personally i don't trust the idea of never changing this oil and feel that changing it may be of some benefit, but perhaps instead of the oil being a problem, there is a faulty sensor telling the box to get ready to change gear when it is not necessary?

Since i have no other problems with the gearbox, i do not think that the problem is related to oil level, but i would welcome any suggestions that anyone may have with regard to this.

I have taken the car to the Dealer, and he drove the car for 20 minutes, before he eventually detected the same thing. His response was that he had never encountered this before. His explanation was that this gearbox has separate clutches for each gear, and that since the car has a high mileage, perhaps the clutch associated with the 5th gear is worn due to lots of motorway driving. His solution is a new gear box!

Please, any help would be appreciated, as would any suggestions as to where to get the cheapest replacement gearbox, if necessary.

[Crasher]

First of all get a fault code read done on the gearbox.

I think your box has failed but please do not go just for the cheapest replacement available, that will normally lead to the money you spend going down the drain so you have to start again.

[Hogman]

Many thanks for your reply Crasher, but i forgot to say that the car has had its fault codes read and there was nothing there related to the gearbox.

When you say that the box may be dead, do you mean that this fault will get worse until the box eventually fails completely?

And with regards to replacement boxes, any advice that you have would be welcome.

[Crasher]

In that case have the fluid and filter changed and see what happens.