Gears difficult to engage after puddles

[c.morewood]

I've got the dreaded running through a big puddle and 3rd gear being difficult to engage syndrome. I remember seeing a discussion a couple of years ago on this subject, but can't find it in the search.
I can't remember if anyone came up with an answer to stopping the water ingression and precisely where it was being ingressed to.
I've got a service this weekend so would like to, whilst under the car, try to stop the ingression.
Is it down to selector rods, or in the gearbox itsself? Is water getting in there and raising the level of the oil so that it makes gear selection difficult? (I've had this problem the first time I did the gearbox oil change and put a bit too much oil in)
Any answers gratefully received.
Chris

[RichardW]

I believe the ML box is prone to shipping water in through the breather if you drive through too deep water - suspect this is what you have done. Changing the oil should restore the change. Whether you can stop it happening again, I don't know - no idea what the design of the breather is, whether you could run a hose up to the top of the engine bay or something to put it out of harm's way?

[c.morewood]

I suspected as much Richard.. I'll have a think about it when I do the gearbox oil this weekend.

[NewcastleFalcon]

Interested to read this. I have more than a suspicion that driving through puddles/flood water, and water ingress contributed to the demise of my automatic gearbox a couple of years ago. The first failure loss of drive, slipping, spanner light on, occurred after driving home in a monsoon through many patches of standing water. The box in question was an Aisin Warner TF-80SC, AF40/6 (six speed). Have to admit it was fitted to a Vauxhall Vectra, but the same box is fitted to many Citroen, Peugeot, and Renault models.

Now I avoid puddles at all costs, it turned out to be a very expensive. Knowing what I know now I think I would have tried a full oil change pretty much instantly. The fault from complete loss of drive resurrected itself by pulling over, a period of rest and switching off and switching on again. It then became an intermittent fault, mostly when warmed up, but became progressively worse over a period of weeks resulting in the rebuild.

My advice If you have an Aisin Warner TF-80SC, AF40/6 (six speed) autobox in your C5 don't drive through standing water!

regards Neil

[Old-Guy]

Water in through the breather makes sense: dousing the gearbox casing in cold water will make the air in the top of the box contract suddenly, sucking in whatever surrounds the breather; if that's water.....

It's a common problem with all sorts of equipment on boats. Deck-level lights in rough weather are a particular problem. The only effective solution is to run the wires through pipes back to the cabin and completely seal the lights/pipe above deck. It's not possible, because of the pressures involved when the equipment is hot, to get a water-tight seal without some form of breather.

[c.morewood]

But maybe it is possible to redirect the water away from the gearbox.. I'll have a look at that tomorrow.

[dnsey]

Perhaps this thread should be read alongside the recent discussion about whether undertrays have any useful function...

[c.morewood]

I always have had the undertray. I think its because of the inside of the wheelarch at the gearbox side isn't as complete as the opposite side and allows more water in. I@m going to take a better look tomorrow and see if there's something I can come up with to deflect most of the water away.. It's just getting embarrassing, if not dangerous, not being able to get into 3rd gear when pulling away and having to go back to 2nd again.

[qprdude]

Surely 4 x 4's use snorkel breathers?

[Hell Razor5543]

It could be worth considering changing the gearbox oil. It isn't difficult to do. You will need 2L of Total BV 75W80 oil (you can get it from Citroen, about £15), and the gearbox takes 1.8L. Filling the box is best done through the reverse switch hole. Do make sure to get the right oil, as some gearboxes won't be happy with anything else.