Mercedes power shift problem

I have an issue with an 08 mercedes power shift box. It has trouble changing sometimes ,gives a warning beep when it misses then has another attempt at the shift. Sometimes it completes the shift on the second attempt sometimes it gives up and selects neutral. If i shift the joystick it gets the gear then :cry: problem is worse when the truck is cold 5th and 11th are the two gears it struggles with most. Tried a gear cylinder which seemed to make it worse and put a new clutch in on Friday. It didn’t help either. Not sure what to try next my dealer hasn’t seen this problem before either.,
Anyone :bulb:

Hi you could need a soft wear up date or your selector actuator is a problem as we found on ours but if you fitted a clutch did you replace the thrust bearing and calibrated it to the gearbox

does it throw a fault code up,do you still have to do the stupid teach in procedure with the 08plate as you do with the 04plates?.

It’s purely a guess, but as it happens more when it’s cold, I’m thinking maybe the air pressure regulator valve?

If you have problems with the gearbox ring mercedes benz callout and they will shift it into neutral for free.
The gearbox is fine but the crap ecu unit they have bolted to it is a load of bloody garbage.
How the hell they have been allowed to sell this crap is beyond me.Going to cost them a lot of money.
Should have a lock out unit till full air supply is available fitted.You apply a gear then have to release hand valve to supply brake chambers to release hand brake,pressure drops and box doesnt have enough air to apply clutch or shift into neutral, vehicle stalls and your stuck.Truck wont start because its locked in gear.
Bloody useless crap.

You can still do the basic reteach but when you have problems like that it’s better to get merc computer on it

It’s not a problem the “teach in " can solve that’s only usefull after the box has been worked on or reset. I doubt if it’s an air supply problem merc’s work on 3 separate circuit’s if it stick’s in gear"which mine has” a problem less obvious than low pressure is usually the cause.
I will suggest the air pressure valve is examined though :sunglasses: Merc have had the computer on it and no mr code’s have been logged. In my experience with Mercedes the wiring is usually not at fault surprisingly,it tend’s to be component failure. The ecu could be the problem as the problem occur’s in the same gear’s 1,2,3,4,6,7,8,10,12 have not had trouble engaging as far as I recall. Keep the suggestion’s coming and thank’s so far.
Matt :slight_smile:

You sould alway re- teach a merc gearshift after the box has been removed as you have removed the clutch servo to get the box out

senior50:
You sould alway re- teach a merc gearshift after the box has been removed as you have removed the clutch servo to get the box out

My ■■■.

ellies dad:
It’s not a problem the “teach in " can solve that’s only usefull after the box has been worked on or reset. I doubt if it’s an air supply problem merc’s work on 3 separate circuit’s if it stick’s in gear"which mine has” a problem less obvious than low pressure is usually the cause.
I will suggest the air pressure valve is examined though :sunglasses: Merc have had the computer on it and no mr code’s have been logged. In my experience with Mercedes the wiring is usually not at fault surprisingly,it tend’s to be component failure. The ecu could be the problem as the problem occur’s in the same gear’s 1,2,3,4,6,7,8,10,12 have not had trouble engaging as far as I recall. Keep the suggestion’s coming and thank’s so far.
Matt :slight_smile:

MR codes are engine faults GS are box faults

ellies dad:
It’s not a problem the “teach in " can solve that’s only usefull after the box has been worked on or reset. I doubt if it’s an air supply problem merc’s work on 3 separate circuit’s if it stick’s in gear"which mine has” a problem less obvious than low pressure is usually the cause.
I will suggest the air pressure valve is examined though :sunglasses: Merc have had the computer on it and no mr code’s have been logged. In my experience with Mercedes the wiring is usually not at fault surprisingly,it tend’s to be component failure. The ecu could be the problem as the problem occur’s in the same gear’s 1,2,3,4,6,7,8,10,12 have not had trouble engaging as far as I recall. Keep the suggestion’s coming and thank’s so far.
Matt :slight_smile:

gears 5 and 11 are the same sounds like an internal prob with that cog or syncro hub to me.

Bking:

senior50:
You sould alway re- teach a merc gearshift after the box has been removed as you have removed the clutch servo to get the box out

My ■■■.

No thanks don’t think I could teach your ■■■ anything you have it all covered

No you should set the parameter green lines on the DAS so that the cruise control works.
Re learn and peramatisation are not the same thing.
Re learn is about as much good as bugger all.Better to go into GS and delete faults and you might just get home(but I doubt it)
Had 5 boxes (sorry ECUs ) fail last week.No problem with box or clutch just crap electronics that allow any bloody muppet to “drive” a truck.

the ecu will be next to be replaced at least we can rule it out if need be. another mp2 with a similar problem still hasnt been sorted . new clutch gear cylinder and actuator new 4 way valves even checked wiring from head to transmission. do the new powershifts still give this trouble. do other brand autos run better or do the clutches give up after 200 ks like mercs.

Ellies dad, we have changed everything on these bloody boxes,booster packs,shifter valves,gear index plates,ecu and nothing works.
Had a truck pull in the yard the other night no faults.Driver backs into a gap and uncouples.All drive gone just flips between manual and auto on dash.

Take out DAS and log into gearbox ecu comes up code 32 clutch fail.
Disconnect battery leave for 5 minutes reconnect still nothing.

Go into GS on dash delete fault and we have gears again.Till you reach 6 then looses gears again.Appears to me that there is a fault on range change shift as these are now a 3 over 3 box with split and it cant shift range.
Once an auto box dont know what gear its in it cant select the next shift and shuts down.
absolute crap.

As anybody checked the driver

Is it just me or is it about time truck manufacturers returned to the simple things in life like manual gearboxes etc , and saved everyone problems .

gs05 came up on the dash today any ideas what it means.

When you fitted the gear shift cylinder, did you put plenty of fish paste/silicone grease around the piston seal and cylinder bore. Had something similar with mine but it was when the g/box crossed over between high/low range when crossing between the 4th and 5th whole gears (4 over 4 ,16 speed box). New piston seal and lubricant solved the problem.

i didnt fit the cylinder joe my mb dealer did does the work. they have an excellent reputation so i guess a yes to your question. hows yours going.