Renault marketed their AL4 as sealed for life years ago ,dip sticks primary use is to check the kevel of the fluid , units where you have to take the pan off are classed as sealed for life as the average person does not have a clue where to start systems like this are deemed dealer only ,Honda baxi auto trans on 1999 was sealed unit with all of the failures it only lasted to 2003

The filter was sealed inside the unit you would have to take the unit apart to get to the filter ,there videos on you tube to substanciate this , what the comment was trying to put across was that the fuid does not last for the life of the vehicle

These systems are designed for the vehicle to be taken into the dealers in the advent of limp mode due to the complexity of modern vehicles there often no reference to problems other than to take the vehicles into the dealers ,

The only reference in the renault hand book to the limp mode is you spent to much time in traffic or to long on the motorway or you have been carrying /towing to much weight [Modus manual ]

the fact that there is a fluid condition sensor in the unit to monitor viscosity and temp means when the fluid looses its viscosity it will flag limp mode

On certain applications of PSA vehicles there is a digital counter in the transmission software software that counts upto 32000 miles and then flags limp mode [citrone training manual for dealers ]

i hope this clarifies the reason for stating sealed for life ,as far as the owner is concerned its sealed !

OH ok then the Al4 unit has what Renault call a condition sensor fitted in the bottom ouside of the case the unit it mesures the heat/vicosity of the fluid starting from the known cold vicosity of the recomended fluid this read by the computer that will trigger limp mode if it reads the fluid is to hot/ thin = lower preasure , the sensor is made by Delphi i have 3 secvice traning manuals covering diferent applications and software of the units for PSA France covering Renault / Citrone /peugeot !

you can find one in an automatic modus /senenic /megan /Clio but they are a just a heat sensor basicly bit expensive at arond £65 but you might have to check the price out though plus they are appx 20mm dia !

Edited by peter moss on 15/01/2017 at 21:13

In my previous work i was under a lot of new cars every day, during the fashionable period for so called sealed for life (or 100k if you're lucky) autoboxes, well lots of cars and expensive 4x4's with not the best reputations for reliability did indeed have stickers/plates on the underside of the gearbox stating either sealed for life or non serviceable.

you must be old school your right look through most hand books for automatic vehicles and anything to do with the transmission is dealer only , and yes i found another make of fluid for the renault i checked the numbers on the back of the container you could put in VW /Honda ect same spec and half the price ,

i flushed my transmission out filled with fresh it drives like a good auto should a lot smoother than before , back in the day i bought an American AMX 304 V8 no forward or reverse dropped the unit and stripped it the clutches were gone i rebuilt it with ford capri clutch plates and spaces [same size ] plus a new seal kit it ran well they did not have the problems auto units have to day , i also use extra magnets on the oil pan just in case there is any metalic bits floating around same on the oil filter .