Gears "Floating"!
 

Hi All,

My XC90 D5 is the 185 BHP and has the Asian Weiner 6 speed auto box installed with 178,000 miles.

Last year I did a gearbox oil flush and (foolishly) reset the adaptations and since then I have had what I can only describe as "floating" when going into 2nd & 3rd whereby it half engages and then drops into gear when at low revs / slight acceleration.

it's irritating me beyond belief as it's inconsistent as sometimes it snaps into gear nicely and other times is worse.

I have gone through programming the adaptations etc with start-stop through the revs etc but it's still not settled so to speak.

Now if I drive in manual I get absolutely no slip in any gear at all and it drives beautifully so I'm thinking that there is possibly an issue with the oil/level/pressure in the system for the auto system to opp[erate correctly?

So my question:

1) Should I do another oil change and re-programme the adaptations again through VIDA again? Perhaps I used the incorrect spec oil (I'm sure I didn't but...)
2) Should I do a flush with a gearbox additive to clean the crap out of the gearbox (Liqui Moly Certec I have purchased with this in mind). Then refill with fresh oil?
3) Is my gearbox just dieing and there is no point?

Thoughts, please!:confused_smile:

nigel.

Take a sample of the current state of the fluid. You can't eliminate that unless it's bright red, clean and clear.
Also, did you reset the fluid counter when you did the change?

I will need to check the colour but I did a 20 litre fill and drain as per the videos posted so it was 99% replaced with manol fluid and the same volume of fluid was put in that was taken out.

I'm sure I did it correctly.

Yes, I did reset the fluid counter also.

The fact that the gear changes in manual with no-slip and there is a good gear changing when the revs are up suggested to me a stuck/sticking pressure value/solenoid?

Henc my thinking of a detergent clean of the gearbox.

I have checked the fluid I used and it is Manol and the right spec - so any thoughts?

Not sure if it helps but mine started doing similar about 10000 miles after a complete rebuild but upon changing the engine and they completely changed the gearbox oil again as it was out it solved it.

They did put genuine oil back in it not sure what they told me is true but they said other spec oil isn’t quite the same as what Volvo use please don’t moan at me for that only going by what I was told but it did drive a whole lot better after.
Not sure if the oil goes slightly thinner than Volvo oil and causes minor loss of pressure which causes it but only guessing.

When it was rebuilt it wasn’t Volvo oil in it only the right spec they told me. I changed the oil in my gearbox with a different oil over the years and it was ok but never quite right so I will be sticking to Volvo oil in the future.

Well, I'm going to do a 20-litre refill of the gearbox today using the following oil:

https://www.ebay.co.uk/itm/303081772419

I'm also going to use the Liqu Moly gearbox cleaner: https://www.amazon.co.uk/Liqui-Moly-...c=1&th=1&psc=1 fists - once I have cycled through the process for 10 mins I'll fill and drain until the 20 litres is used up which should give me completely clean fluid in the box.

I'll then reset the fluid counter and adaptations and take the car for a drive and follow the adaptation process.

Wish me luck - I'll report back later :)