Auto box. 4th to 5th problem.

[RhayaderSax]

I've searched but can't find anyone that's had a problem quite like this...

2006 facelift 3.0 V6 CDTi auto.

• When changing from 4th to 5th the gear change can be “felt.”
• When under load (eg: going uphill) the problem becomes a lot worse – changing with what feels like a clunk, almost like the engine mountings have come loose! (they’re not – it was MOT tested last month).
• The problem is random. Some 4th/5th changes are smooth but most can be felt.
• The problem occurs under all driving conditions, ie: both gentle & hard driving.
• There is no loss of power or erratic engine revving when the problem occurs.
• When coming to a stop it can also be felt when it drops in to neutral. Previously this couldn’t be felt.
• All other gear changes are completely smooth.
• There are no fault or warning lights illuminated.

It's been to the dealer & had the transmission fluid changed. Made no difference. Am I right in thinking that the change from 4th to 5th is the torque converter's lockup point? Is it the torque converter (rather than the gearbox) that's likely to be the problem? If so, what sort of cost?

I've emailed Vx as something like this shouldn't happen to a (regularly serviced) 5 year old car that's done less than 60k.

[RhayaderSax]

BUMP! Obviously I need to drive the car (wouldn't own one otherwise!!) but I'm worried about the fault escalating & ending in a breakdown. In addition to emailing Vx, I need to speak to someone there to help get this sorted ASAP.

Does anyone here have a friendly contact within Vx customer services?

[paulvectrac]

When you apply the foot brake at a total stop they do go in to neutral have you changed the transmission fluid

[RhayaderSax]

Transmission fluid changed - made no difference. At complete stop there is a very small jolt when it drops into neutral. Never used to be able to feel it & it started the same time as the 4th/5th gear problem.

[dae36]

Transmission fluid changed - made no difference. At complete stop there is a very small jolt when it drops into neutral. Never used to be able to feel it & it started the same time as the 4th/5th gear problem.

It sounds like damage to the valve body has already been done, but if it were me I'd do a complete change of the fluid before anything else, as if you have taken it vauxhall they have only drained what's in the pan (which is only half the fluid). To do the full change you need to get the fluid in the Torque Converter out, by flushing with the engine running and 'D' engaged.

If you're only runnning your autobox with the very poor stock cooler and you want it to last the life of the car, it is essential to change the full 8 litres or so, of ATF approx every 30,000 miles. Extreme heat above 200 degrees, degrades ATF very, very quickly. Fitting an aftermarket cooler keeps the ATF temperature down, therefore prolonging the life of it!

[RhayaderSax]

Cheers for the advice dae. The dealer said they did a complete fluid change & also said that the old fluid that came out wasn't too bad. The computer showed no faults & the next step would be stripping it down. £££ in labour just to diagnose. It might have been something relatively cheap but it could also have been mega £££ to fix.

I bit the bullet & got rid. A shame because I really liked that car but the replacement is awesome: 220PS Insignia 2.0T Elite nav auto 4x4. I do count the lamp posts to the gallon though!