Citroen XM Forum

Hello to all.
And gearbox/help needed.
Hi, I am a new owner with a V6 12 valve automatic, unfortunately it is currently languishing in a garage for the last week, after all drive was lost.
I have searched on the internet for a 4hp 18 gearbox, but have been unsuccessful.
To be honest I have to make a decision in the next few days on whether to proceed with repairs, or cut my losses and move on, as the owner of the garage has said he wouldn't bother repairing it if he owned it, because he doubts it has got another MOT left in it without a lot of "alchemy" underneath.
If I can actually find a Gearbox it may help to influence my decision.
Any help would be much appreciated.

Hi there.. firstly where in the world are you? There are a few knowledgeable v6 owners on here. All loos of drive could be as simple as the valve block or the governer seals however im not a huge autobox expert..

The loss of drive was preceded by a rather large bang as I crossed a Dual Carriageway roundabout, then a gradual loss of drive until it stopped.
After that, nothing, no forward or reverse gears, just a long walk home.
I am in Norfolk.

I was very sorry to hear about your gearbox problem, although you are in the right part of the world to secure assistance! It just happens that I am also in Norfolk at Aylsham and I have had a good deal of (bitter) experience tinkering with the V6 and autos in particular! Please do sent me a PM with your location and other contact details and I would be happy to get in touch and help if I can. With regards, Matthew T.

Thank you.

Hows about that then. I was thinking mathew or dean...

At a guess, from the symptoms described, I would say that either the transmission oil pump has broken, or the torque converter sprag clutch, or the torque converter stator support shaft. The latter 2 particularly if you had power applied when it went bang. Unfortunately any of those failures really need a change of transmission (and torque converter), or a complete rebuild, due to the risk of metalic debris circulating in the oil.

I think in this case as with any mechanical failure, if there is a 'bang' prior to a complete failure to proceed then a lot of work will be involved to get it running again. I would bet the issue lies with the oil pump or it's drive, at a guess i would say the pump drive on the torque converter nose sheared off but the first course of action would be to get the engine and gearbox out and have a look.

Sorry to hear about your woes, do you know how bad the rust on the chassis is?

D

Another possibly might be the flexplate disintegrating as I experienced on one of my cars, although it would not be a sudden failure. Hopefully it is possible to give some help as I am very nearby! Regards. Matthew T.

A flex plate failure, even a sudden one (which historically has never been the case) would indeed give different symptoms.
Another possibility is a diff or driveshaft failure but this should be easy to
Diagnose before removal of the box

D