AL4 Automatic Gearbox

[Nexus]

Now that my 1.6 automatic is on 97.5k (covered 40k in five years) I've decided to go through with a full transmission fluid change. This thread is essentially to document my symptoms, findings, experience with Peugeot and ultimately the final outcome on the box itself post fluid change.

I've been doing plenty of reading about the AL4 gearbox which is fitted to TU engined Peugeot and Citroen vehicles - But please do read through information online very thoroughly before undertaking any work on your own vehicle - Pinch of salt and all that! Here some symptoms I've been suffering recently which I feel relate specifically to the AL4 gearbox:

• On a cold engine, 1st gear hangs for a while before a harsh shift up to 2nd (hanging can be intentional to warm the engine quicker but should be smooth)
  
• Even on a warm engine, sitting in traffic 1st to 2nd, then 2nd down to 1st clunky
  
• Temporary, complete lose of speedometer when coolant gauge reaches roughly 70c. Speedometer reading returns after 1-2mins, occurs daily.
  
• With car in P or N, shifting to D or R takes a few seconds. Maybe followed by humming noise while stationary in D or R (Hydraulic pump).
  
• The obvious one: Sport & Snow icons both flashing simultaneously when ignition switched on. This is the Fluid Wear Counter or Check/Replace Fluid warning.
  

With these issues in mind, quite frankly I have never had the transmission fluid level or condition checked. I am hoping that the majority of the issues above are a cause of low transmission fluid or just simply old fluid that needs replacing. I did at one point attempt to replace my speedo sensor on the gearbox and this gave me a little peek at the color of the transmission fluid which to me personally looked fine. A sweet, candy red colour, unburnt. The sensor itself seems to be fine, which then got me thinking about the actual fluid level itself.

So I'll be taking the Estate to a Peugeot dealer next week for a diagnostic on the box to see exactly how it is holding up in its current condition, then a fluid level check and then finally a full fluid flush. If you are attempting to change the fluid at home you'll only be able to change roughly 2-2.5 litres at a time as the majority of it is held within the Torque Converter. The dealer should be able to use a vacuum system in order to perform a 90%+ flush.

I have read that early type AL4 gearboxes were pretty dire and that this was due to the solenoids and/or pressure regulators on the valve block. There was a revised regulator and solenoid released which can be changed over and then Ecu updated accordingly. This apparently had a good positive effect. Getting Peugeot to perform a diagnostic I am hoping that they will be able to give me a picture of whether this upgrade/fix is required.

So a few facts for you:

• SPORT & SNOW flashing simultaneously on the dashboard is a warning to check or change your transmission fluid.
  
• AL4 Gearbox must only take Esso LT71141 Fluid. DO NOT use Dexron type fluids.
  
• Esso LT71141 is a stock item and can still be bought off the shelf at your Peugeot dealer at £12.91 +Vat per 1ltr bottle. (I'll post the part number shortly)
  
• Gearbox valve block may also benefit from a solenoid and/or pressure regulator change. Only the two solenoids at the top of the valve block are affected. About £65 each if I recall.
  

Once I have a report on the condition on my gearbox I'll post an update - At the moment I don't think there is anything on 306oc for Automatics. Gti Fanboys!

[puggered]

• On a cold engine, 1st gear hangs for a while before a harsh shift up to 2nd (hanging can be intentional to warm the engine quicker but should be smooth) Low fluid level, there's no control from the engine ecu or sensors to the transmission other than TPS.
  
• Even on a warm engine, sitting in traffic 1st to 2nd, then 2nd down to 1st clunky Clunky shifting on 2nd and 1st is a sure sign that the fluid level is low or the solenoid(s) are sticking.
  
• Temporary, complete lose of speedometer when coolant gauge reaches roughly 70c. Speedometer reading returns after 1-2mins, occurs daily. This is most likely coincidental, Had the same thing and replacing the new sensor with a decent brand one cured it. The cheap ebay ones went open circuit when they got hot.
  
• With car in P or N, shifting to D or R takes a few seconds. Maybe followed by humming noise while stationary in D or R (Hydraulic pump). Low fluid level
  
• The obvious one: Sport & Snow icons both flashing simultaneously when ignition switched on. This is the Fluid Wear Counter or Check/Replace Fluid warning. This is by design, it's the startup check by the transmission ecu although they shouldn't flash more than a cpl of seconds. When they flash while being driven it's caused by low fluid 90% of the time.  
  

The transmissions were supposed to be a "sealed for life" item but invariably leaked fluid.
I've had,rebuilt and worked on both the early and later transmissions and the symptoms remain constant regardless of the solenoid type.
I personally think the older solenoids are better provided the rest of the box is working well. (valve block, converter and fluid is good)
My son currently has one with 1/2 milllion Km's on it and still going strong.

[Nexus]

• On a cold engine, 1st gear hangs for a while before a harsh shift up to 2nd (hanging can be intentional to warm the engine quicker but should be smooth) Low fluid level, there's no control from the engine ecu or sensors to the transmission other than TPS.
  
• Even on a warm engine, sitting in traffic 1st to 2nd, then 2nd down to 1st clunky Clunky shifting on 2nd and 1st is a sure sign that the fluid level is low or the solenoid(s) are sticking.
  
• Temporary, complete lose of speedometer when coolant gauge reaches roughly 70c. Speedometer reading returns after 1-2mins, occurs daily. This is most likely coincidental, Had the same thing and replacing the new sensor with a decent brand one cured it. The cheap ebay ones went open circuit when they got hot.
  
• With car in P or N, shifting to D or R takes a few seconds. Maybe followed by humming noise while stationary in D or R (Hydraulic pump). Low fluid level
  
• The obvious one: Sport & Snow icons both flashing simultaneously when ignition switched on. This is the Fluid Wear Counter or Check/Replace Fluid warning. This is by design, it's the startup check by the transmission ecu although they shouldn't flash more than a cpl of seconds. When they flash while being driven it's caused by low fluid 90% of the time.  
  

The transmissions were supposed to be a "sealed for life" item but invariably leaked fluid.
I've had,rebuilt and worked on both the early and later transmissions and the symptoms remain constant regardless of the solenoid type.
I personally think the older solenoids are better provided the rest of the box is working well. (valve block, converter and fluid is good)
My son currently has one with 1/2 milllion Km's on it and still going strong.

Appreciate the fast reply and added info! It would be nice to compile a bit of information and member's experiences with the Auto 306's. After reading your additions I'm curious to perform a top up myself over the weekend, prior to my visit to the dealer for a full change. See whether this has any significant improvement beforehand.

[puggered]

If you have access to PP2000 you can reset the wear counter, this seems to have a positive effect on the transmissions as well.

The AL4 is common as mud in Aus', however most of them have been abused and have a lousy reputation because of it.
There's quite a lot of detailed threads on aussiefrogs.com if your so inclined as well.

[Nexus]

So just an update - Had a part fluid change performed at my nearby peugeot dealer and unsurprisingly the car is just like what I remember when I first got my hands on it five years back. Only had a short drive home but very smooth changes both up and down, no hanging in gears. Pressure and solenoids appear absolutely fine from what I was told so many more miles of happy driving in my 1.6 Automatic.

Thanks again to Puggered above for the additional confirmation of my issues. I'll possibly leave another update after another 1-2k miles or something. The speedo sensor still needs changing over, I've got one from GSF thats been sitting around for ages waiting to be done.