[Tim1300Turbo]

Hello from Australia!
I have an MB Trac 1300Turbo and am getting it ready for a spraying job over our Summer.
I cant get the front wheel drive to engage. I have removed the air actuator, lubricated selector fork, replaced the O-ring on the selector piston and have 120psi (7-8Bar) at the actuator. When I turn the switch, I can hear a clicking in the actuator put still the front axle wont engage. Both diff locks work as normal.
Any ideas before I pull the gearbox out as a last resort?
Thank you for adding me to the forum.

[Roby]

Hello Tim,

its also possible that the Toothing from the cardan Shaft is worn out.
You can check this by lifting the Front axle with four wheel and Diff.Lock engaged and turning a front wheel.
Then you should to listen a Noise in the Pushtube behind the Front differential.

Greetings
Roby

[Tim1300Turbo]

Hello Tim,

its also possible that the Toothing from the cardan Shaft is worn out.
You can check this by lifting the Front axle with four wheel and Diff.Lock engaged and turning a front wheel.
Then you should to listen a Noise in the Pushtube behind the Front differential.

Greetings
Roby

Hello Roby,
I did try this initially but couldnt hear any noise, Ive just split the torque tube at the gearbox end and found that the 4WD system is working,but the diff pinion isnt working.. so yes its a stripped spline on the drive shaft are they compatible with any Unimog models?

Greetings
Tim

[optimog]

Hello Tim,

Crown and bevell gear is a matching set with one Number depending on the axle ratio.

There is a 27/7 Ratio (A 443 330 04 39) and a 25/8 Ratio (A443 330 05 39)

both were used only with the MB-trac heavy series BM443. They are not compatible with any Unimogs.

But "reproductions" may be available here in the Forum.

Check here: https://www.trac-technik.de/Forum/showth...?tid=28310&pid=172772#pid172772

but if you get lucky, only the splines from the driveshaft are stripped?

It is part number A442 337 00 10 but again was used only on these MB-trac.

best regards
Wulf

[Tim1300Turbo]

Hello Tim,

Crown and bevell gear is a matching set with one Number depending on the axle ratio.

There is a 27/7 Ratio (A 443 330 04 39) and a 25/8 Ratio (A443 330 05 39)

both were used only with the MB-trac heavy series BM443. They are not compatible with any Unimogs.

But "reproductions" may be available here in the Forum.

Check here: https://www.trac-technik.de/Forum/showth...?tid=28310&pid=172772#pid172772

but if you get lucky, only the splines from the driveshaft are stripped?

It is part number A442 337 00 10 but again was used only on these MB-trac.

best regards
Wulf

Thank you for the information and part numbers,Ive pulled the torque tube off and found that the Pinion has snapped. The splines are all good and not twisted, I cant understand how this has happened. Is it possible to only fit a new pinion without splitting the diff and renewing the crownwheel as well.

Regards,
Tim

   

[Roby]

Hello Tim,

normally it have not a weldseam at this point.

   

Someone have repaired the Pinion unprofessional, unfortunately you have to change more Parts.
Ratio and Axle type are printed on a metal label in the front of Diff.casing.


Greetings
Roby

[Tim1300Turbo]

Hello!
I have had the front differential pinion fixed. My engineering company cut the old pinion in between the 2 bearings, oversized a new shaft, turned it down to get the right size and straightness and then cut a new spline, very professional job, big job to fit it in the field, but a test drive today and all is good, 4WD is working as it should, thankyou for all your help.

Best Regards,
Tim

[optimog]

sounds like a reasonable bush fix.

have you got any Fotos from that repair?

best regards
Wulf