Hi guys,

Can some help clarify the way this transmission is supposed to work? I am very familiar with the ZF unit and how Sport mode behaves, but what about the Mercedes?
I've only had it on the road a couple days but haven't noticed much difference between Sport or nonsport modes. Is first gear used in Sport? Is reverse the same in either mode? Do the shift points get higher like the ZF?
Tonight I am going to test drive it again. At full throttle and Sport mode it was shifting at 4800-4900 rpm. I now realize I wasn't pressing hard enough to activate the kickdown switch. So on a quiet country road I'll try it again and see.
All input is welcome, thanks.

 

It utilizes 1st gear and upshifts later- if you turn off traction control it will light up the wheels when you punch it from a stop..... That was one of the first things I tested.

 

Also, check to make sure your accelerator cable is tight so you get 100% throttle...

 

In sport+4 it also avoids torque converter lockup.

There is a adaptation procedure for the Merc transmission. Didn't make much, if any, difference when I did it.

 

There is a brief description of the W5A580 (722.6) in the XJ intro guide on page 50.

XJ Sedan 98MY Intro_jjm18151280.pdf

The gearbox is interesting because there are 2 reverse gears.

bob gauff

 

2 reverse gears? Bob, could you explain that?
Thanks,

 

Hi Bob,

The document you listed isn't linked, thanks.

 

I suspect the kick down switch is not working. At full throttle it shifts at 5000 RPM in sport mode.

 

The XJ sedan MY98 intro .pdf is a large file (around 8mb) So I don't think it will upload to the posts. It should be somewhere in the large file download area.
It says that the file size limit is 9.57mb but I have failed to upload any more than about a 3mb file.(I just tried and it FAILED)

The W5A580 has 2 reverse gears, The HIGH reverse gear is engaged in the NORMAL mode and the LOW gear in the SPORT mode. (I have never tried to switch between them 'on-the-fly' to see if the difference can be noticed)

Page 57 of the document describes the shiftpoint calculations as well as basic operation and LIMP MODE.

The document is called....

XJ Sedan 98MY Intro_jjm18151280.pdf

bob gauff

 

OK thanks Bob, I'll try to find it. I removed the kickdown switch, took it apart and cleaned it, and now she pulls to redline. And wow is she fast!