Unimog U500 blue tech 4

[kins12]

Hi, Have a Unimog 500. 2 questions

how do i recalibrate the clutch after replacement

And , does anybody know why it jumps out of gear when driving? you can be going along in 8th and all of a sudden it will go into neutral, then it will start doing it in all the gears, to get it home you have to put it into emergency mode.
Leaving it until it goes cold and it is fine until it gets hot again, obviously it seems temperature related, but all fluids are fine, no warning lights, no error codes.

 

[mogwildRW1]

Depends on the shifting system. There is a teach in process View attachment Perform minor teach-in process on control unit.pdf

 

[kins12]

MogwildRW1

Thanks for your reply, I will try this tomorrow.

Any ideas on why it is jumping out of gear/ putting itself into neutral when hot??

 

[mogwildRW1]

MogwildRW1

Thanks for your reply, I will try this tomorrow.

Any ideas on why it is jumping out of gear/ putting itself into neutral when hot??

Note that the "Teach in process" is different if you have EAS or not. Here is an example of the process WITH EAS (code G48) View attachment Perform major teach-in process on control unit With EAS.pdf

Could be any number of gizmo's, I've only seen a few U500's in person. You may wish to track down M37Charlie, he's pretty proficient with the U500NA. Do you have EAS? You can PM me your VIN and I'll see what worksheets I can dig up (there are 8 models of U500, from 405.200 to 405.230). Was the clutch replaced? (I mean, I assume it was by the title of the post but..you know, asking anyway ) who did it? was the system properly bled afterwards? Was proper fluid used? Do you have the STAR diagnostic system? Any error codes? Might be time to visit a certified shop for a scan and diagnose.

I see there's some steps to tell it (the computer) the clutch has been replaced and to re-measure the open/closed state of the clutch for (I assume) clutch thickness using the FIS Display in the cab, but again, I'm shooting in the dark as I have no real experience outside of the keyboard with one of these units.

Also please note the info I've posted is for the 405.230 (North American version) as I'd need your VIN to look up what version your truck is.

 

[kins12]

Hi

It does not have that rocker switch on the console, so I guess it is without.

I'm a competent mechanic, but never worked on a U500 before. I changed the clutch myself and I bled it thoroughly with correct fluid.

Clutch feels fine and then on occasion it just goes hard, it still works, but goes hard. After a couple of pumps it goes light again and is fine for several hours.I have been told it needs calibrating. I will try your teach process tomorrow.

I want to get the clutch right first before diving further into the gear issue, the 2 might be connected?

I dont have the serial number to hand but will get it tomorrow

Thanks very much for your help

 

[kins12]

Note that the "Teach in process" is different if you have EAS or not. Here is an example of the process WITH EAS (code G48) View attachment 281744

Could be any number of gizmo's, I've only seen a few U500's in person. You may wish to track down M37Charlie, he's pretty proficient with the U500NA. Do you have EAS? You can PM me your VIN and I'll see what worksheets I can dig up (there are 8 models of U500, from 405.200 to 405.230). Was the clutch replaced? (I mean, I assume it was by the title of the post but..you know, asking anyway ) who did it? was the system properly bled afterwards? Was proper fluid used? Do you have the STAR diagnostic system? Any error codes? Might be time to visit a certified shop for a scan and diagnose.

I see there's some steps to tell it (the computer) the clutch has been replaced and to re-measure the open/closed state of the clutch for (I assume) clutch thickness using the FIS Display in the cab, but again, I'm shooting in the dark as I have no real experience outside of the keyboard with one of these units.

Also please note the info I've posted is for the 405.230 (North American version) as I'd need your VIN to look up what version your truck is.

I think this is what I need to do, so it knows the thickness of the clutch, could you post these steps??

 

[mogwildRW1]

I think this is what I need to do, so it knows the thickness of the clutch, could you post these steps??

That process is only for units with Electronic automated gearshift (EAS).

 

[charlieaarons]

Did you bleed in accordance with the directions in the WIS? It is easy to leave air in these systems.
If the clutch intermittently gets much harder than normal there might be a problem with the clutch booster.

Charlie

 

[kins12]

Did not bleed it according to workshop manual, as I dont have one. However it was clutch down with bleed point open, close bleed point and clutch up etc etc whilst having a small amount of air pressure on the fluid pot.

Carried out the teach process this morning, it all went as the instructions said, no errors codes.

Took the machine on a road run, with no load, after 30 mins, it went from 8th to neutral, no error codes or warning lights, push the selector lever forward and it preselected 8th, pressed the clutch pedal down and she went into gear, 100 yds further it went back into neutral, again no codes or warning lights.

I pulled up on the side of the road and tried the teach process, it would not go past stage 1 of the selector relay clicking.

After that it showed an error code "GS 18"

in another screen it showed "a 4440 GS"

then in another screen it showed :

E 1
2 4440
Sensor



Any ideas on the error codes ??
All help greatly appreciated

Also, what goes wrong in the clutch booster??

 

[charlieaarons]

Code 24440 is "clutch travel sensor has an open circuit"
The clutch travel sensor is an integral part of the throw-out (center) bearing of the clutch apparatus. Did you hook it up incorrectly or damage it?
GS 2 4 4 4 0 = CLUTCH TRAVEL SENSOR HAS AN OPEN CIRCUIT

Charlie

 

[kins12]

Still struggling here

After finding that error code, i left the machine until next morning, when I went to it next morning it was working fine and no error codes.

I test the resistance through that switch, clutch travel sensor, when the clutch pedal was up, 50% down and all the way down.

I cleaned the connections, sprayed wd40 into it and went on a run to test it, after 45 minutes it started going into neutral on its own, I pulled up on the side of the road and tested the resistance again through that switch, it was the same as before, so to me it indicates the switch is ok.

I then tried the teach process and it came up with that same error code G 2 4440

Got it back to the yard in emergency mode and unfortunately i had to leave it for the rest of the day.

Just been to it now, the machine is cold and there is no error code, it will take the teach process and it drives normal.

Still scratching my head, anyone with any ideas??

 

[charlieaarons]

Did you use the same throw out bearing when you replaced the clutch or put in a new one? Did you disconnect the wiring to the clutch travel sensor at any time?
The problem is intermittent, obviously sounds electrical.
I would ask a real Unimog workshop familiar with the new Mogs what they think of this.
If you did replace the throwout bearing it might have a defective sensor in it, that fails only when warm.

Charlie

 

[kins12]

just the clutch plate was replaced, bearings were all okay.

the only disconnected part was the plug that goes into the housing

 

[charlieaarons]

You might try communicating all these observations To Rob Pickering. He used to work for Unimog North America and now runs an independent shop and is very knowledgeable re the U500 - obviously like the U400.
unimogrob@yahoo.com
phone 1-719-241-5419
He is in La Junta Colorado.
The parts concerned are identical between U500 NA and your U400.

Charlie

 

[kins12]

Another error code flashed up today briefly, it has gone now


fault code was ; E2 2 8093 transmission, could someone tell me what this is