XSeries-forum

Hi guys,

My X5 has a intermittent harsh 2-1 downshift. Reading around, a Zip Kit seems to be able to fix the problem and makes for smoother changes throughout.
Sonnax Zip Kits come from America so I want to be sure to order the correct kit.
Would anyone know if the 2005 3.0 Diesel uses a ZF6HP26 transmission and requires Generation 1 (WITHOUT separator plate) or Gen 2 kit?

I had no idea what a zip kit, and in seven years of being on this forum I have never heard of one, nor do I recall any 'kit' being the fix for the problem that you have (although others may correct me). Some say an oil change fixes it, some say its a software update. Some say it is gearbox on the way out. Ive had the issue for five years - never done anything to it and its never got better or worse

Search on the forum for the dreaded 'lurch' before attempting a fix.

Smee

Hi
It may be worth giving Jason a ring at BW Chiptine his contact details are in the performance section of the forum on under E53.

He knows a lot about this and could help with a possible solution to the lurch if you have it. He did the same for my old car by coding new settings for the gearbox where by it improved the smoothness of the down change from 2nd to 1st

Graeme

Thanks guys, will contact Jason.

Here are a couple of links that might help those in search of a fix for the lurch

http://www.sonnax.com/zip_kits
http://www.bmwlogicseven.com/?p=3738

Or do a search on this forum and read the posts there

[quote="freddo"]
Hi guys,

My X5 has a intermittent harsh 2-1 downshift. Reading around, a Zip Kit seems to be able to fix the problem and makes for smoother changes throughout.
Sonnax Zip Kits come from America so I want to be sure to order the correct kit.
Would anyone know if the 2005 3.0 Diesel uses a ZF6HP26 transmission and requires Generation 1 (WITHOUT separator plate) or Gen 2 kit?
[/quote]

Generation 1.

The 2005 diesel uses 6hp26. The gen2 was 6hp28,

http://www.sonnax.com/tech_resources/11 ... lve-bodies

If You are going to go to the effort of the zipkit,
(which is a great idea) might be worth changing the solenoids as well.

Let us know how you go;

I'm thinking of doing the same.

[quote="freddo"]
Thanks guys, will contact Jason.

Here are a couple of links that might help those in search of a fix for the lurch

http://www.sonnax.com/zip_kits
http://www.bmwlogicseven.com/?p=3738
[/quote]

Did you contact Jason? What did he say?

Yes it's the Generation 1 kit for 6hp26

Good idea about the solenoids deepblonde