AL4 Maintenance Recommendations?

[asaf400]

Hello,
I'm a new owner of an 2010 C5 X7 (RFJ),
And I would like to perform some Maintenance on my AL4.

Currently after driving for about 20 to 40 minutes, depending on throttle aggressiveness throughout the drive,
Shift are getting rough, accompanied with a delay in shift, banging sound and feel, and I don't like that very much, the roughness can be eased by applying the throttle very lightly, but that is no fun ..
even the AL4 in my Xantia lasts longer (until oil is too hot)

Taking into account that I would want to do the proper long lasting, peace of mind Maintenance,
What procedure would you guys recommend?

The car has done 184k Kilometers, and the last recorded gearbox maintenance was in 2016,
where new Solenoids were installed along with some kind ECU Download \ Update.

• Just Changing the Oil + Oil filter?
• Changing the Oil + Cleaning the hydraulic valve body?
• Changing the Oil + Oil filter + Cleaning the hydraulic valve body + Replacing solenoids?
• Changing the Oil + Oil filter + Cleaning the hydraulic valve body + Replacing solenoids + Replacing clutch plates / brake plates + bands? - basically a gearbox overhaul

I'm currently in the process of scoping out Certified Citroen Shops and independent shops to carry out the Maintenance.

[ozvtr]

To change the filter requires a tear down of the gear box. If the filter is clogged then you have way more to worry about than a clogged filter!!
The electro valves can get "sticky" with tiny particles and their longevity can be questionable. Just because they were changed does not mean they wont go faulty again.
Without regular fluid changes the the brake band friction material can wear down and the attaching rivets can begin to run on the drums, causing slipping and damage.
The Gearbox is NOT "sealed-for-life"! The hydraulic fluid has a finite life and it's required properties deteriorate over time!
If you ask 5 different people what fluid to use in the gearbox you will get 5 different answers! I can only tell you the specified fluid is Esso/Mobil LT71141. Some people claim that specification is a bit old and more modern fluids are better.
The two pressure sensors that tell the gearbox ECU what the gearbox pressures are, can also go faulty.
I personally don't recommend cleaning the valve body unless you know what you are doing. If the tiny galleries are blocked they would need to be ultrasonically cleaned anyway and the pressure regulators in the valve body are set at the factory, you run the risk of upsetting them.
I've had a bit to do with the AL4 but I am NOT an expert! I can't tell you what's wrong with your gear box but the first thing I would recommend is changing the fluid. If that fails, change the 2 modulator valves. Then the pressure sensors. After that you are looking at a gearbox rebuild.
A reasonably competent person can change the fluid, the sensors and the electro valves but after that I would recommend seeking "professional help".
The best piece of advice I could give to anyone who owns an AL4 is to change the hydraulic fluid regularly!

[asaf400]

Thanks @ozvtr,
I would not do anything on my own, I am planning to go to a gearbox expert anyway.
So you recommend to first do a fluid change try it out, and then doing the more semi external components (2 modulator valves, pressure sensors), and if issues persist, go for the full rebuild..

I really love the feel of a good working AL4, or even other torque converter based boxes,
as opposed to the Dual Clutch (Dry or Wet) Robotic boxes in all of their flavors in other brands.

They shift faster, They give you more snappy torque from a full stop (IMO)
Thanks for the advise, and if anyone who has experience getting their car through a maintenance like that can pitch in that would be also great

[asaf400]

Updating: Last week I finally pulled the trigger, and went to the shop requesting an oil change,
The shop says it only uses PSA AL4 Oil, and doesn't work work 3rd party suppliers (Mobil ATF lt-71141 has been recommended several times for AL4 in forums)

So far just did the first round of oil change, drain & refill 4 or 5 bottles, I'll do the 2nd full oil change (after old from TC and new mixes ) soon after driving a bit,

Anyways, I'm VERY happy to report this oil change so far has been a Great Success!
Everything is better, torque, responsiveness, kick-downs, shifting, overall, I am feeling like I've gained at least 20+ horses (hp) back to my car's performance just from this first change.
There's still some knocking in certain shifts when oil is at temperature, but it's 25% of the strength it once was.

The change was very apparent when I was getting off the highway in 4th gear with no throttle, and the car had very little amount of engine braking in comparison to before, just kept rolling.

Edit: typo

[ozvtr]

Good job.
What fluid did you put in the gearbox? LT71141?
I have two Citroen C3s with AL4 gearboxes. One is running what I believe to be LT71141 and the other is running a fully synthetic fluid.
The fluid I think is LT71141 is not marked as LT71141 compatible, currently. However historical documents from that oil manufacturer say it used to be equivalent. The odd thing is that the fluid is amber, unusual, and same colour as LT71141!
However, the gearbox running the fully synthetic oil, runs better, IMHO!

Citroen have gone away from recommending an "outside manufacturer" and now just recommends their "stuff". What's in it? Is it any good? Don't know...there is no specification!! You must realize Citroen (PSA) don't make oil...or coolant. So who's product are they using? The best stuff, or the best stuff for their profits? Don't know, just saying.

[asaf400]

Sorry that I'm super late, So the shop I went to just used their recommends "stuff" so official Citroen AL4 Oil.

But, I think now that the new Oil (2 changes) had time to.. integrate,
My AL4 is back to somewhat back to it's old days,
Driving more then 35 minutes when it's 30 degrees C outside and it starts slipping then harshly transferring between 1st and 2nd, and etc, etc..

So Oil change was good, but it doesn't help with the rest of the old age issues:
- Possible build up of contaminants/gunk in the hydraulic block
- Old Solenoids
- Worn out braking bands
- Possible worn out clutch pack

After this coming winter, before the next summer, I'll have to send my car for a full gearbox rebuild.
I got a shop close to me that does only hydraulic block cleaning, and Solenoids replacements, but I'd like to do more, check and or replace all wearable components..