Drive in 2nd only!, no drive and slipping in P,R,N,D,1&3, AL4 Gearbox, no fault codes, no snow and sport lit?

[stevedh]

Hi, I am hopeful that someone can help me with this odd problem.

I have a 2006 Citroen C3 mk1 with an AL4 automatic gearbox (20TS19) and have a strange problem.

All was working fine, but then broke down with strange noises from the engine and no drive.

Once I got the car home, I scanned with transmission module and there are no fault codes, tests on all the electro valves seem to work just fine, I have oil pressure and the snow and sport symbols are not lit, so the TCM does not think there is anything wrong.

But the car has no drive in any gear except 2nd (when in manual selection).

In all other gearbox positions, P, N, R, D, 1 and 3, there is a scraping / rubbing noise from the gearbox, which I assume is either rubbing clutches or brake belts. But for some reason after a large clunk, gear 2 goes into drive with no scrapping / rubbing noises and wants to move the car.

A few months back I had harsh gear changes, so drained the box, replaced the two modulating valves at the top, refitted and refilled with fresh oil to the correct level (drained to a dripping when warmed up) and then the gearbox ran just fine again.

Since the break down I have now drained the oil, removed the valve block again and checked all looks good and the inner filter is not clogged and no signs of dirt etc. I have also swapped the positions of all the electro valves to see if this would change any behavior, but after reassembly and refilling the box with oil, there has been no change to the symptoms. I have also readjusted the multifunction switch as per the correct procedure and again no change.

I have also removed the pressure sensor and oil flow control valves and cleaned them to ensure there where no blockages with them.

I seem to be getting between 2.35 and 3 bar of oil pressure in any gear.

I am now at a loss as to what could be wrong, I assume it must still be something to do with the valve block, but have no idea what.

Does anyone have any ideas? Why is 2nd ok but the rest not, what could cause this?

Much appreciate any feedback.

[ozvtr]

Looks like a mechanical failure of one of the clutch packs.
From the AL4 manual, the clutch pack P1 or its actuator are the only components used in every gear except 2nd.

Edit: P1 is the planetary gear housing. The associated clutches are E1 and F1. If it's not the clutches then the planetary gear housing might be damaged.
My bet is the E1 clutch. Either way sounds like a mechanical failure.

[stevedh]

Thanks, for the response.
Is there anyway there could be something gone in the ECU that controls the solenoids?
I have changed the valve block for a recon unit with no change in symptoms, so either something inside the box, or the ECU.
The car only has around 70,000 miles on the clock, so surprised why it would be a mechanical issue in the box, but I guess it is getting old.

[ozvtr]

Anything is possible but with a "scraping / rubbing" noise coming from the gearbox, I'm still of the opinion its a mechanical failure.

[xantia_v6]

I would concur. Maybe something has broken causing a clutch pack to slip, or a previous valve block fault has caused long term slippage of a clutch pack which now has no friction material, or maybe the transmission has chronic low oil pressure for some reason.

[lcwin]

your pressure between 2.35 to 3 is likely low. At idle it 2.8 I think. Your AL4 is likely mechanically damaged ( brakebands usually first to go) . Dont drive it or you be stranded suddenly. Look for autobox mechanic as this box is pretty common .

[stevedh]

Thanks, I have looked for a replacement, but the 20TS19 is very rare. I know the core is an AL4, so I am thinking that what is special is the bell housing. Can anyone confirm if all core AL4 boxes have the same gear ratios and it is only the bell housing that changes and this changes the part number? Can I simply get a used 20TS28 or 20TS60 and simply switch the bell housing and maybe the oil cooler and then reinstall and the car will work fine and the ECU will not complain? If not, does anyone know which model AL4 boxes have the same ratios as the 20TS19?

[xantia_v6]

AL4 transmissions have different ratios depending on the weight of the car and the torque of the engine. The core epicyclic ratios are (I believe) all the same, but there is a pair transfer gears which can have 2 or 3 different ratios, and the differential gears can have 2 or 3 different ratios. It is unfortunately difficult to find a cross-reference with the mapping of gearbox part number (or car model) to different ratios, although I think I have seen somewhere a specialist parts listing which gave the number of teeth on each gear.

[stevedh]

Thanks, that is helpful. The car is in great condition and I am willing to change the box, but it is proving very difficult to find one.

[citroenguy]

I think the late Xsaras had this engine/box combo, and maby Pug 206?

Part no is:
2222 ZY up to orga 11801
2231 A0 from orga 11802

[Haakon]

The core is also the same as Renault DPO. Renault boxes are better to find a low miles used one as Renault used a good quality full synthetic ELF fluid from factory and they last much much better than PSA cars that had rubbish part mineral fluid.