2006 Citroen C4 Auto | AL4 slipping in 1st gear eventually engages with a clunk, when warm

dimistyle, shanadoo, ozVTR and jaahn, thank you heaps for your insight. ozVTR, your guide is excellent, you should charge for viewing it! I was wondering why no webpage loaded when I clicked the link originally!

I have a bit of a background in using tools and feel confident now with replacing the two main solenoids (EVM and EVLU) and not needing the special tool anymore. I'm now deliberating as to whether it is worth putting the valve body on a bench, taking it apart and doing a full clean. I probably won't anyway because I won't be able to set the positioning of each and every check valve, slider or spring.

Now time to buy valves. There's the el-cheapo ones here https://www.ebay.com.au/itm/154474299741?hash=item23f762c15d:g:pd4AAOSw9PhiAxJA

Has anyone had experience with the cheap ones? Are they as good as the more expensive ones? I've read that the cheap ones can be dead before being used. If I buy two of the more expensive ones, am I guaranteed to have both working regardless?

Should I purchase these ones instead? They look genuine but could have been replaced out with the cheap ones in the same packaging too https://www.ebay.com.au/itm/263439360516?epid=19017001573&hash=item3d5635a204:g:9vwAAOSwGBdasivC

Or maybe these ones? They are more expensive and might have a better chance of being genuine? https://www.ebay.com.au/itm/222214878035?hash=item33bd09f353:g:RUkAAOSw65FXrR-Z

Thanks everyone! If i'm ever out your way I'll shout each of you a beer.
 
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The Renault item is the same as the Citroen part, so the 2nd option is better than the first. EAI were carrying the Renault part.
If you are going to take the valve body apart, you need to measure the depth of each adjuster or note the positions in some other way. Don't forget to replace the o-rings between the valve body and case.
There is no guarantee that replacing these electrovalves will fix your problem. You really want to have read a fault code involving a pressure regulation error. There are other things that can go wrong with this gearbox, such as harness faults and even friction plate debris in the cooler. If one or more of the clutch packs has worn out, oil changes and electrovalves won't fix it.
 
Hi c4nub :)
All the valves I have purchased in the past were in genuine bags from PSA or Renault or Fiat. So I would go with the second one. We never had one fail. But I have replaced some that had been changed not long before in a car and the receipts were there. Possibly not genuine. I would leave the valve body alone if it looks clean enough inside the transmission..
ozVTR,:)
I read your tutorial and it is good. It is hard to precisely describe a complicated job. As you say the manual is sometimes unclear and not particularly dedicated to that job on the car in situ And it is a translation so that never helps and I have had to correct the English version of some European manuals as they did not make sense. I do believe that the official manual is the starting point for information. However as the usual job is just a 2 valve change in situ and it is not easy to get at in there, I have done it with my short cuts as I saw it, but others may be less experienced.

I would advise people to read and follow your tutorial if they have minimal experience. You have given plenty of good advice and pictures to help. It would be most peoples first dive into an auto transmission, hell what could go wrong. :oops: It is a while since I have done one so possibly I will bow out. Getting too old to do it myself now. But I am pulling out a Fiat gearbox soon and putting a new bearing and seal in, hmm some people are slow learners :rolleyes:
Jaahn
PS You might ask the moderator to get the links fixed and working.
 
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David S said:
Tried and not able not make it work. Maybe, to do with C3Owners site?
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I am not very savvy when it comes to internet stuff and I don't know why I cant link to it. Did you try the "cut and paste" method?
 
It's still not straight forward. Here it is:
 

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I was not happy with the quality of the last couple of photos, so I have re-done them. Hopefully they are a bit clearer.
With the roller blade under tension you may need to use two hands to slide it. One to pinch the blade and quadrant and one to help slide the blade spring.
 

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To check that the quadrant is against the stop after tightening all the bolts, pull the roller blade outwards, off the quadrant, wiggle the quadrant to be sure its against the stop, then ensure the roller blade engages directly into the #2 position detente when the blade is set back against the quadrant. The quadrant should not be pushed back off it's stop when the blade engages in the detente.
 
This post all seems too heavily involved. Really it's not rocket science. Leave the control valve alone, you don't want or need to go there. Replace the electro valves and hope for the best. By it's inherent bad design this is a high wear transmission. Yours is 16 years old and my guess is if the solenoids don't work the box will need a full overhaul. It's not your fault. Everything seems to wear out on them at once. As a guide, the mainshaft will need replacing as well as the bronze bushes, clutches, brakes and the list goes on. You can play around with diagnostics, loose sleep over oil pressure or lack of it, change the oil as many times as you wish but, in the long end, it's overhaul time. They are not a good unit. But having said that, there's very few gearboxes which will run as they should after 16 + years of constantly changing up and down. I wish you the very best of luck.
 
Thanks all! I purchased the second link of valves (Renault group branded). I will change out the EVM and EVLU solenoids with a second ATF change and report back for an update.

I will inspect the valve body instead of taking it apart. It seems there is no need to take it apart based off other's experiences.

I checked the issue with an OBD by referencing coolant temperature. It only happens when the car bakes in stop start conditions and the coolant temperature is slightly over 90 deg C. The problem only occurs at taking off after stop/start where it winds revs up and eventually clunks into moving forward. For highway driving, no issues at all. To me, this brings suspicion to ATF cooling or to a brake band or clutch. I looked at how shanadoo changed out the E2 clutch from the front left wheel well and that seems very doable, but i'm not sure if the brake bands are accessible.

If the solenoids don't work, my next best guess is to look at the oil pump in the AL4. I can inspect it just before I put new ATF in. Any signs I should look out for when checking the oil pump?

Cheers!
 
Hi c4nub :)
The transmission CU reads all the transmission sensors, and the input from the engine ECU and then compares the expected results to the 'lookup tables' in its memory while deciding control actions. If the readings are out of the expected range it will remember a fault and makes some adjustment to the action. If it happens more times it flags a fault and puts the light on. A serious fault will give a more serious correction leading to a several stepped "limp home mode" responses. More than one step.;)

A factory scan tool will tell you what the pending codes are and will read them correctly while a generic reader will only give general answers. On French cars that may be just a guess. They do use EOBD anyway not OBD2. It will also read and display problems in real time so you might be able to 'see' what is happening to the temperature and the valve selection etc as well as rpm of the input and output speeds.

My suggestion is get a lexia clone, now called diabox in the later versions, and look at what is going on before you go any further than the oil and 2valve change. There is discussion about setting them up on here and suggestions on what to buy. I believe the newer versions are easier than the earlier ones.
Jaahn
 
Brake bands and oil pump cannot be changed with AL4 still fitted to vehicle. This is a remove and split job.

Changing the clutches via the wheel well requires lots of patience, I've attempted this several times and gave up after crushing the thrust bearing at least twice.

Checking the gearbox heat exchanger is an option to check if clogged or worse leaking oil and coolant.

Finding anyone AL4 splitting and rebuilding can sometimes be an easier task with some basic tools, but knowing the condition of the replacement would be helpful before embarking on this job.
 
Thank you for your insights jaahn and dimistyle! I will keep it in mind. Expecting to change out the valves sometime later this week and will update. I'll check the gearbox heat exchanger and report back.
 
Changed out the valves, seems to shift smoothly however the problem is still there once coolant temp reaches 95 degrees in stop start traffic. The car just winds up and then shifts with a bang when taking off. I could not find any leaks either.

When draining the oil and inspecting the valve body, there was only metal debris on the two magnets. Attached pictures.

I also could not find the heat exchanger. 95 degrees seems a bit high for coolant temp, and is an odd issue to be having at only higher temperatures.

Up to last resort before complete overhaul, using some lucas atf transmission fix. I'll use half a bottle for now I think, and use the other half if there is some improvement.

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The AL4 heat exchanger is on the top at the rear left.
 
c4nub said:
Up to last resort before complete overhaul, using some lucas atf transmission fix. I'll use half a bottle for now I think, and use the other half if there is some improvement.
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Magnet debris is normal [it's a high wear gearbox] Lucas additive is good stuff don't be frightened to use it. Heat ex changer sits on the side of right hand back top corner, standing on left side of car, looks like sardine tin with large central bolt. You will need new seal rings. Bitch of a thing to get at, but doubt very much if this is your problem. My thoughts lie with the E1 clutch over-traveling due to wear. But be warned I have been known to be wrong, albeit rarely. "joke joke".
 
Thanks seasink and shanadoo! I'll have a look at the heat exchanger and add the Lucas additive and report back. I'll also look at the clutch replacement kit and see if it's something I can do with my tools and space. If only I had the space, i'd have pulled the whole AL4 out by now!

The issue seems to happen from a lack of shift from 2nd to 1st or into reverse. For example, at a traffic light, I can manual shift up to 2nd and it works fine. However, for 1st and reverse, it seems to struggle to shift into gear without using some accelerator to bang it into gear. It would make sense for the issue to be a common clutch/brake band to 1st and reverse.

Is there a non-destructive/non-pull-apart way to verify the E1 clutch is not engaging?

Turning out to be a fun project car actually haha. Just bad timing personally.
 
Maybe, I missed it, but did you read any fault codes from it?
 
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