Automatic Gearboxes, are they all the same?

I'm considering buying an XM automatic and being aware of the reputation for unreliability of XM auto boxes and assuming that at some point I'll have to change it, I was wondering if the same auto box is used in all XM's, or are there several different one's. Also, will a Xantia auto box fit the XM.

Paul.

Hi Paul

I am not really sure that the auto box is all that unreliable, if the CORRECT fluid has been changed REGULARLY. I think many people just ignore oil changes in many gearboxes (manual and auto) but the auto box will suffer more than a manual one when it is running in dirty oil.
As for compatibility I'm not sure but i think the xm was fitted with two auto boxes, the HP18 and HP20, the 18 was a purely mechanical unit fitted to earlier models while the 20 was of the adaptive type with an ECU controlling gear changes which i think was fitted to the MK2's.
In my opinion though, get an auto, they suite the XM much better than a manual .

I have two autos now - one on 119k, the other on 172k - both are lovely smooth changers and show the absolute minimum of debris on the mag plugs. The 172k one actually changes slighty better than the other one.

It may just be wishful thinking, but to keep them boxes in good order on a newly acquired car I always drain the fluid, flush through with 3 changes (about 4 litres each change), then finally fill with Amsoil synthetic ATF (the best - but pricey at £50 for 5 litres). It's worked so far, even with the latest cars' fluid looking very brown and burnt smelling - I suspect it's been a good while since it was changed, if ever (170k!!!).

P.s- got my ATF from a seller on ebay doing a box of 12 x one litre bottles of good quality ATF at £30 delivered. It's branded 'Quantum' but on the bottle is actually the brand name for the VW group. Cheaper than my normal budget ATF (flushing) fluid from comma.

Having a spare car with the same auto box gives a little peace of mind however.

This post has been edited by wirdy on February 09, 2008 02:30 pm

Hi Paul,

The 4HP20 auto adaptive box is fitted only to the late model V6s, all other automatic XMs have the 4HP18 unit.

Derek

This post has been edited by DerekW on February 09, 2008 04:01 pm

I stand corrected

Thanks for the advice chaps,

I'll probably get the auto XM, so I'll be looking out for any cars heading for the scrap heap which might have a decent auto box, best keep a spare.

Thanks again,

Paul.

I have a VERY GOOD auto box attached to a 2.oi NON Turbo engine, sitting in waiting..

I kept it as I drove the car and it was smooth.. other wise I wouldn't have bothered.

I've also just bought a 2.oi Onyx Auto, with 157k and its actually a smoother changer then my V6!! How mads that! Mind you my V6 is at about 176k, but when I put the engine and box into mine, the ATF was red, so it had been looked after

As for the Onyx, I've not yet chancked it. Its resting again now while other pies get cooked and finished....

Rgds
citroenxm

Mine has done 101,000 miles and changes sweet as a nut.

Bitontheside

We must get together and exchange notes, your only up the road from me!

I'm on Anglesey,other end of the A55!!

citroenxm

I'm just by Cheshire Oaks - that mad place where women like shopping!

citroenxm

So can I assume that one will be available to purchase if I need it sometime in the future?

Paul.

I'm not sure you will learn too much from me vis-a-vis our XM's. I might learn quite a bit from you though!