Auto box operation.
 

Hi,

I’ve had my XC70 for a month now and I’ve have a few questions before I head back to the dealer to get it checked.
2008 D5 awd 185
Full dealer history and 50,000 miles

Basically I not sure if I have gearbox issues or not.

Does the gearbox lockup in all gears for engine braking? It doesn’t seem to do it in 2nd. If I let off the accelerator the revs drop to idle and pick up again if I press the accelerator.
I feel like there is slippage in 2nd also, if I accelerate from a standstill it will shift to 2nd but only drop about 200rpm then rev steady (ish) like it’s looking for friction then the revs increase without a reasonable increase in speed then change to third the revs drop about 500rpm which is about right for an up shift sometimes I feel the same symptoms in 3rd the rest of the gearbox is fine.
I also experience “flaring” if I’m driving at a steady speed and slightly press the throttle the revs jump 1 or 200rpm then it’s gets grip the revs drop back and it will accelerate. Is this right?
These symptoms are not present all the time but if the car is laden, 3up and bikes on the roof they are more noticeable.
Sorry if these are silly questions but I’d like to get my facts correct before I speak to the dealer.

Terry.

I'm not sure if you have a fault or not or what you expect from the gearbox regarding engine braking but my impression of the AW Geartronic box on my 2012 XC70 is that it is not particularly good at engine braking and you always need to initiate deceleration by using the brakes. The gearbox then catches up as the car slows. I was used to a box where, if you dropped into Sports mode, the box immediately changed down and slowed the car. The AW box does not do this and I find this the thing that disappoints me most with an otherwise impressive car

Your gearbox sounds find to me. I'll just chuck in a few points...

- Engine braking is software controlled by locking up the torque converter (TC lockup) if the TC lockup mechanism fails in anyway - this would generate and error and a message on the dash.

- There are several different software versions that Volvo used on the TF80 and these have different behaviors. And some of these are changed slightly with software updates - hence a S80 D5 might behave slightly differently to a XC90 D5....

- The TF80 gearbox does have a "limited slip" feature (aka "partial lockup") where at lower speeds the TC locks and gives limited engine breaking but changing the applied throttle and cause a small amount of flare. I think this intended to give a smoother drive and mask slightly turbo lag.

- If you knock the gearlever over to the right and use geartronic mode you will find that engine braking is more aggressive and in more gears.

- Some later software versions have a Sport mode which you get when you move the gearlever over to the right but do not select a gear - "S" on the dash is displayed. Again more aggressive shifting and TC lockup.

- ALL versions have a "hidden" sport mode which is selected by how quickly you press the throttle. If you are pottering on a country lane at say 20 mph and stamp on the throttle (and I mean stamp) all they way - you will see what I mean. Again more aggressive shifting and more engine braking.

- All versions adapt to your driving style and the load on the car - if you have every towed a heavy trailer - the car will probably feel the same but as soon as you unload it - it will feel very different for the first 5 miles or so....

One of the issues with the later TF80's is many of the above features are not well documented and some owners mistake the variable/adaptive behavior as a potential problem.

Hope this helps.

I find the same on my 2012, gears 1-3 'slip' but 4-6 lock up. I find this is more pronounced when the engine is cold and is more pronounced in cold weather.

Thanks Tannaton, what a great write up. Alot of what you describe above is exactly what i've noticed in the past with my XC70. I am just about to embark on towing with my XC70 D5 and I was a tad concerned with the box struggling on big hills whilst towing at low speeds. Sounds like the box copes with this by picking up the additional drag and compensating for it.

^^^^ What he said

The behavior of the gearbox is also different when cold - shift points are higher and thresholds for torque converter lockup are much higher. This is deliberate to get the engine and gearbox to operating temperature in the shortest time.

Thanks Tannaton,

I have done a bit more research on Vida and combined with your description it makes a lot of sense. I also have 4c which varies gearbox characteristics depending on setting. I fear I was being paranoid as the xc70 is just so much more of a car compared to my V50 (which I had clutch issues with at 36k) and as it's my first auto it was sensory overload.

Again, thanks for taking the time to help.

Terry.

Do be prepared to change the gearbox oil . The "filled for life " rubbish that Volvo come out with is a lie . 50K is a good time to change it. A car that has been used a lot in town will have pretty much worn the oil out . fresh oil before any faults develop is far cheaper than fixing the box

This six-speed gearbox has the ability to apply lockup at 2-6. Gear switching at normal load is frquently done by first switching to the next higher gear, then a moment after apply lockup. Hence it looks like the gearbox is passing through eleven gears, not six, as the torque converter will hydraulically provide you with a lower gear than the locked up one.

In cold weather, below freezing, there will be no lockup at all, until the gearbox oil has reached a certain temperature. The colder it is, the longer you have to drive.

At least our cars, XC70 from 2012 and 2016, both with geartronic, have significantly more engine braking if you flick the lever to the right/left, to engage Sports mode.

But not enough to safely decelerate the car without applying the brakes. I was used to a ZF box where dropping into sports mode on fast bends automatically dropped a gear and allowed you to enter and then accelerate out of the bend without touching the brakes at all. The gearbox became a sports car driver in sports mode and a family guy in standard mode. The AW box doesn't do this and the difference between standard and sports modes for engine braking is not appreciable on my 2012 XC70. I still love the car but I have had to change my driving style to compensate for the gearbox.