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Terex TA40 driveline questions

Jtf05

Member
Joined
Jan 23, 2020
Messages
18
Location
Illinois
I just bought a TA40 and I’m wondering about the drive line specifically. My first problem is the diff lock won’t work and I haven’t found any blown fuses. My next question is how much power should the rear 4 wheels be putting to the ground? The front axle seems to have all the power while going forward, if the ground conditions are wet or slimy the front end of the truck will spin out all the time while the other 4 wheels don’t spin at all. While backing up the the truck will spin wheels on all three axels. I’m wonder what would cause the difference and this is normal, the truck is very helpless if the ground conditions aren’t just perfect and dry. Any help on how to possibly fix the diff lock and tire spinning issue is much appreciated.
 

Bigbert

Senior Member
Joined
Jan 2, 2016
Messages
326
Location
Germany
Occupation
Consulting Engineer
Is it a TA 40 with ZF 6WG310 transmission or Allison?
On ZF with open difflock there is a torque split of 1:2 , 1 portion to front two portions to mid and rear axle.
With the front axle slipping there is no drive on mid and rear axle anymore. Exactly for these slippery slimy conditions you have to use difflock.
You say in reverse difflock seems to work. This was a special feature on the Terex trucks for a while: Switch on difflock in combi with reverse signal. So, the good thing is, difflock mechanically seems to work properly.
There should be a difflock switch on dash which possibly is broken and does not give a signal to TCU when applied.
Any fault codes on dash display?
 

Jtf05

Member
Joined
Jan 23, 2020
Messages
18
Location
Illinois
Is it a TA 40 with ZF 6WG310 transmission or Allison?
On ZF with open difflock there is a torque split of 1:2 , 1 portion to front two portions to mid and rear axle.
With the front axle slipping there is no drive on mid and rear axle anymore. Exactly for these slippery slimy conditions you have to use difflock.
You say in reverse difflock seems to work. This was a special feature on the Terex trucks for a while: Switch on difflock in combi with reverse signal. So, the good thing is, difflock mechanically seems to work properly.
There should be a difflock switch on dash which possibly is broken and does not give a signal to TCU when applied.
Any fault codes on dash display?

I’m not sure which transmission is in the truck. There aren’t any fault codes showing but it does flash stop on the dash. If I need to look up any information to help you better assess my problems I’d be happy to.
 

Bigbert

Senior Member
Joined
Jan 2, 2016
Messages
326
Location
Germany
Occupation
Consulting Engineer
Can you get me a picture of the gear switch to better identify driveline?
After "Stop" on display going to neutral does display throw a code?
There are possibly two displays, one for Detroit engien, one for ZF (or Allison). Photo?
 

Jtf05

Member
Joined
Jan 23, 2020
Messages
18
Location
Illinois
Can you get me a picture of the gear switch to better identify driveline?
After "Stop" on display going to neutral does display throw a code?
There are possibly two displays, one for Detroit engien, one for ZF (or Allison). Photo?
Yes I will take a picture of it, I’ve never seen any codes come up.
 

Jtf05

Member
Joined
Jan 23, 2020
Messages
18
Location
Illinois
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Can you get me a picture of the gear switch to better identify driveline?
After "Stop" on display going to neutral does display throw a code?
There are possibly two displays, one for Detroit engien, one for ZF (or Allison). Photo?
 

GODSDOZER

Well-Known Member
Joined
Jan 7, 2011
Messages
134
Location
East Texas
Occupation
Dirt Contractor
my TA27 has the exact same A2 error code and my wheels are doing what your are describing as well.I still have not figured it out. Ill be watching this thread.
 

Bigbert

Senior Member
Joined
Jan 2, 2016
Messages
326
Location
Germany
Occupation
Consulting Engineer
Hi guys,
above mentioned TA40 is equipped with ZF 6WG310.
The "A2" code is either a short circuit to battery voltage, but rather a broken solenoid for difflock. Installed somewhere below retarder/converter housing above front output shaft.
"19" on the TA 40 might be solenoid of jake brake (engine brake) or a solenoid reducing engine speed in certain drive conditons (for noise reduction). No effect on regular drive.
Engine brake works?
 

Jtf05

Member
Joined
Jan 23, 2020
Messages
18
Location
Illinois
Hi guys,
above mentioned TA40 is equipped with ZF 6WG310.
The "A2" code is either a short circuit to battery voltage, but rather a broken solenoid for difflock. Installed somewhere below retarder/converter housing above front output shaft.
"19" on the TA 40 might be solenoid of jake brake (engine brake) or a solenoid reducing engine speed in certain drive conditons (for noise reduction). No effect on regular drive.
Engine brake works?
I don’t think I have a Jake break, if I do it doesn’t work. I know that sounds stupid to say but I don’t have any switches for a Jake. Do you think the solenoid is something I can fix on my own or will I need a mechanic to come out. I’m very mechanical inclined working on just about anything is no problem for me.
 

Bigbert

Senior Member
Joined
Jan 2, 2016
Messages
326
Location
Germany
Occupation
Consulting Engineer
If the fault code "19" doesn't bother you too much, just leave it.
Check/exchange solenoid for difflock for better drive. Code "A2" should vanish away with proper load on solenoid plug.
Good luck.
 

Jtf05

Member
Joined
Jan 23, 2020
Messages
18
Location
Illinois
If the fault code "19" doesn't bother you too much, just leave it.
Check/exchange solenoid for difflock for better drive. Code "A2" should vanish away with proper load on solenoid plug.
Good luck.
Would you happen to have a diagram showing the location of the solenoid? I really appreciate your help.
 

Bigbert

Senior Member
Joined
Jan 2, 2016
Messages
326
Location
Germany
Occupation
Consulting Engineer
As far as I remember the difflock solenoid is directly mounted on transmission housing, just behind output flange to front axle, 11 o'clock. Can you take a picture again?
 

GODSDOZER

Well-Known Member
Joined
Jan 7, 2011
Messages
134
Location
East Texas
Occupation
Dirt Contractor
Would you happen to have a diagram showing the location of the solenoid? I really appreciate your help.


That is part of my problem too. The Shop manual I own does a very poor job of showing the "location" of anything on this machine.
 

GODSDOZER

Well-Known Member
Joined
Jan 7, 2011
Messages
134
Location
East Texas
Occupation
Dirt Contractor
As far as I remember the difflock solenoid is directly mounted on transmission housing, just behind output flange to front axle, 11 o'clock. Can you take a picture again?


Hello bigbert thank you for your responses to this thread. Is the solenoid facing towards the front bumper or dump bed ? thank you for your help.
 

Bigbert

Senior Member
Joined
Jan 2, 2016
Messages
326
Location
Germany
Occupation
Consulting Engineer
Hi guys,
the solenoid should be located towards front resp. direction engine.
I'm not sure whether solenoid on smaller truck like TA 25 with 6 WG 210 is separately mounted.
On bigger transmissions like 6WG260 and 310 it should just be behind prop shaft flange. (also towards engine/front axle)
 

Jtf05

Member
Joined
Jan 23, 2020
Messages
18
Location
Illinois
As far as I remember the difflock solenoid is directly mounted on transmission housing, just behind output flange to front axle, 11 o'clock. Can you take a picture again?
Yes I can take some pictures, so there’s just one solenoid that locks all three axels and it’s located some where on the front of the transmission or front axel? Sorry for all the questions I just don’t have a book on this machine and I can’t find any diagrams online.
 

Bigbert

Senior Member
Joined
Jan 2, 2016
Messages
326
Location
Germany
Occupation
Consulting Engineer
Hi Jtf05,
I could share some stuff via email.
regards
Bigbert
 

Bigbert

Senior Member
Joined
Jan 2, 2016
Messages
326
Location
Germany
Occupation
Consulting Engineer
Hi Jtf, did you get the file? Possibly spam folder?
 
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