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300 GE
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16 Posts
Discussion Starter #1
Hello,
I have a 1993 300 GE with electronic differential locking system. When I turn left or right,the differential seems as if it is locked, although I unlock it using the 3 dashboard buttons.

The symptom is the following: only when turning, it seems as if the car is breaking. There is great resistance to turn and move forward or backward when parking for example. You have to force the car to move, or make small turns at a time.

I am not sure if the differential is not releasing the lock or if it is a totally different mechanical problem causing this.

I appreciate any insights into this issue.
Thank you
 

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2000 G500 NMLE
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6,980 Posts
With your name and contacts, you should be able to have your crew chief take care of this for you. [;)]

(I didn't know that you'd moved to Dubai!)
 

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230 G BGS 300G TDI
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965 Posts
Seriously, It sounds like your rear diff lock has not disengaged.
get to a good workshop as soon as you can before you do real damage.
Dependant on how good a mechanic you are I could talk you through a a few ways to try to fix it.
 

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300 GE
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16 Posts
Discussion Starter #6
Thanks Stirling [:)] I have the car in the shop however the mechanic is still trying to fix it with no great success. Any tips would be great! So you dont think we should look into the front but rather the rear diff?
 

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TJs, FJ40s, JGCs, G500
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2,343 Posts
the resistance to move forward or backwards at very slow speeds indicates that the center diff lock does not disengage.
All of the locks need time and more importantly, they need to be driven in a straight line for some time to completely unlock. Just turning off the switches does not mean much.
Only when the wheels left and right are xactly at the same speed the axle diff locks will disengage.
Only when axle speeds front and rear are absolutely equal the center diff lock will disengage. However, if the vehicle has been driven on hard surfaces for some time the binding effect is so severe that the center diff lock will not even disengage when the vehicle is driven straight for miles. Only lifting one axle might help.

Harald
 

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1980 LWB 280GE
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3,504 Posts
If raising the car on jack stands, or the lift since it's at teh mechanic, doesn't result in the diff locks freeing up then the only thing left is to investigate the mechanicals. If axles are not releasing, pull the hydraulic actuator on the axle and see if you can manually slide the internal sleeve away from the diff. If axles are free and the center diff isn't unlocking, then you'll have to start with the actuator there too, though I've never worked on one, so I'm not sure how it goes.

Good luck.

-Dave
 

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300 GE
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16 Posts
Discussion Starter #9
Thank you all for your quick replies [:)]
Do you know of any technical resources, documentations that I can leverage to identify possible causes and fix the problem?
 

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TJs, FJ40s, JGCs, G500
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2,343 Posts
here is your documentation:
"resistance to move forward or backwards at very slow speeds indicates that the center diff lock does not disengage"

You'll have to find out why the center diff does not disengage. Fortunately the shifter can be reconditioned without removing the transfer case.

I have the manuals if you need them:
http://www.4x4abc.com/G-Class/trans.html
 

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300 GE
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16 Posts
Discussion Starter #11
Thanks! We lifted one axle with no luck. The mechanic seemed to think it was the front or/and rear diff. I have indicated to him that the central diff is the main suspect based on your feedback. After checking will let you know.

Thanks again for the links. As a beginner in off-roading and troubleshooting mechanical issues, these tips greatly help me get up-to-speed. Appreciate it.
 

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230 G BGS 300G TDI
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965 Posts
You seem to be getting lots of advice from near to home but in case it doesnt solve your problem I will email you my UK phone number then as a last resort I can talk you through a possible fix
 

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300 GE
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16 Posts
Discussion Starter #13
Hello again,
After checking the problem, MB Technician said the problem is caused by the Transfer Case. If they open it they have to change all parts (MB procedure!) otherwise they will change it. In other words, they cannot tell me what the exact cause within the transfer case is. In both cases it is just too ridiculously expensive.

I am looking for another mecahnic (couple I saw did not have the skills to operate) and/or a used Transfer case in the mean time; however what do you suggest I should start with? Shifter?

4x4 Rancher, let me know if you are availble for phone discussion.

Thank you
 

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1984 280GE Cabrio
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256 Posts
If a axle is locked with the transmission in neutral and you lift the axle off of the ground both wheels will turn in the same direction,unlocked in oppisite directions.
 

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230 G BGS 300G TDI
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965 Posts
Have you tried changing the relay that activates the electro magnetic pump that pressurises the cylinder that drives the centre , or for that matter any of the diff locks. disconnct all electrical leads at the diff locks and see what happens, you could be lucky and only need a relay. or perhaps a switch.
 

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2000 G500 NMLE
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6,980 Posts
4x4rancher - 3/7/2005 3:18 PM

Have you tried changing the relay that activates the electro magnetic pump that pressurises the cylinder that drives the centre , or for that matter any of the diff locks. disconnct all electrical leads at the diff locks and see what happens, you could be lucky and only need a relay. or perhaps a switch.
It's actually vacuum actuated, not pressurized; and there are connections to the intake manifold vacuum as well as the vacuum assist pump - through one solenoid valve.
 

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1989 300GD SWB
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84 Posts
But then again, vacuum is just negative pressure[:D]

Sorry, am in pedantic mood tonight[xx(]
 
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