Renault Automatic Transmission

[bobpearson]

Anyone out there understand Renault V6 Laguna auto transmissions.
I have a troublesome one, I have tried the usual such as fluid level and state of the filter and they are all OK. The symptoms are as follows: In drive the change from 1st to 2cd is perfect, the change from 2nd to 3rd is untidy, in that it is slow and revs a lot as it goes through. The change from 3rd to 4th simply goes into a false neutral and never actually reaches 4th. The timing of all the changes including the one that doesn't get completed is fine. It seems to me that whatever tells the system to change is fine, but the actual act of changing is faulty for the 2nd to 3rd change and even more faulty for the 3rd to 4th change. I don't know enough of the details of an auto box to read a solution from those symptoms, can anyone help?

[bobpearson]

Kevin,
It is a 95 car, with a lot of miles on it (147K )

We cartainly don't intend getting into the area of replacing the box, the car isn't worth that.

[bobpearson]

It's beginning to look like a one way trip to the auctions! Actually the oil looked clean and didn't smell unusual in anyway. We have only just brought the car from an auction, so the chances are that the previous owner had changed the oil in an attempt to cure the problem.

[bobpearson]

delta,
Your coming to my rescue again, I stiil haven't managed to put your recommendations on the Cavalier into practice what with crap weather nad trying to prepare racing cars. At least this one sounds like a more straight forward solution.

[bobpearson]

I don't think it will be the same box as the 25, as the Laguna has a computer controlled affair. Anyway we have decided not to waste time or money on it and it is going for the chop!!

[bobpearson]

It's interesting you referred to the correct transmission fluid. Is there a requirement for something special in these cars. I don't know what is in it, but there are transmission fluids in Halfords for instance which seem to be aimed at all systems.
Should it have a particular fluid and what could happen if it has the wrong one in?