Slipping auto box - Vito

[Hogie]

Hi - forgive my first post here being one asking for technical help but I have been lurking on this site for a while ['reserching' Vito's befor etaking the plunge.
I have just bought a 2007 115 CDI Vito Dualiner (W639) with automatic transmisson and taken a bit of a punt on it as there is slight transmission slip when changing up from 2nd to 3rd. It all works fine in the othergears and there is no issue going down the gears, only changing up.
Does anyone have any opinion on likely causes? Vehicle is low mileage 50k and came with no service history so I am assuming the transmission has never been serviced
David

 

[WG M-B]

First thing to have check fluid condition and level. After that it could be a valvebody problem, or a component in the main transmission power train causing oil pressure loss/ slip. First port of call is fluid and filter. The tech can look for signs of damaged fragments when the sump is removed.

 

[Hogie]

Thaks Wayne. I was wondering if it could be a sticky valvebody as it only happens between 2nd and 3rd. In your opinion, would a fluid and filter service be enough to 'un-stick it or will they need to physically get deeper into the gearbox?

 

[Tuercas viejas]

Might I suggest you probably have a lot of contamination of the conductor plate speed sensors and therefore the shift is confusing the TCM d causing the shift delay with some possible flaring conditions.
The initial remedy is to fully service the transmission unit by a total fluid purge and replacement of the circuit board and filter etc.
2007 mercedes vito transmission - Google Search:
The two sensors I mention are seen in the attachment 5n2 5n3 as sticking up round like pillars. One controls initial 1/2 shift, the more f'ward one 2/3 shift (your corrupted culprit )
Once serviced i always add a can of BG ATF Plus to the genuine MB fluid for a super shift quality and amazing customer perception on shift quality.
All the best
Tuercas viejas

 

[WG M-B]

No it’s unlikely it would cure a valvebody issue.

Thaks Wayne. I was wondering if it could be a sticky valvebody as it only happens between 2nd and 3rd. In your opinion, would a fluid and filter service be enough to 'un-stick it or will they need to physically get deeper into the gearbox?

 

[Hogie]

Wayne -thanks again for the replies.
Tuercas - the link is really helpful so thank for that and the advice, always good to know what to look for when I get inside!
David