4hp20 gearbox has developed a whine

[jgra1]

ahh not sure..
Jim got a headache on this a while ago.. pretty sure it was a coupe 406 (which are only 2.2) box for a V6 xant.. something was different, sure it was the ratios or change up points or something ;;

[Mandrake]

I'm sure I remember CitroJim saying that the XM with ES9J4 has a 4HP20 with a different final drive ratio to the 4HP20 in a Xantia with the same ES9J4 engine. Not only that but the ECU is programmed differently to accept the different final drive ratio, so the final drive ratio of gearbox and ECU have to match otherwise the ECU throws up a fault code.

Jim's XM has a 4HP20 from a Xantia fitted and only works properly when a Xantia gearbox ECU is fitted!

Aside from final drive ratio and the presence or absence of a dipstick I'm not sure if there are any other significant variations between different 4HP20's...

[Chris570]

I'm sure I remember CitroJim saying that the XM with ES9J4 has a 4HP20 with a different final drive ratio to the 4HP20 in a Xantia with the same ES9J4 engine. Not only that but the ECU is programmed differently to accept the different final drive ratio, so the final drive ratio of gearbox and ECU have to match otherwise the ECU throws up a fault code.

Jim's XM has a 4HP20 from a Xantia fitted and only works properly when a Xantia gearbox ECU is fitted!

Aside from final drive ratio and the presence or absence of a dipstick I'm not sure if there are any other significant variations between different 4HP20's...

Yep that's the case, I think (FYI) it's about a 5% difference, with the XM being longer.

I know the torque converters are different between them and i've got a feeling the gear ratios are different as well between the 2.2 HDi and the ES9.

Regarding the offer of a box I strongly suggest you get a reconditioned TC in there, don't use a second hand one (unless you know it's history and has very low miles). Getting your one recon'd isnt expensive and it tends to be the TC that fails that throws its crap into the filter blocking it, starting a wonderful cylce of pain and damaged bank balances.