4WD won't unlock

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Ugo
Posts: 91
Joined: Fri Apr 23, 2004 8:07 am
Location: Italy

4WD won't unlock

Post by Ugo »

Trying to find out all problems in my 716 ...
The 4WD locks without problems as soon as I flip the switch, but is very "lazy" in unlocking. The only way to get a quick unlock is taking a sharp turn (city cornering e.g.).
What should I check?
Tightness of lock vacuum pipes?
Old grease in locking mechanism?

Thanks,
Ugo
The true Pinzgauer´s
Posts: 34
Joined: Sun May 08, 2005 10:31 am
Location: Nürnberg, Germany

Post by The true Pinzgauer´s »

Hello Ugo
There can be many problems.

First :
check your plastic-tubes to the Diff-Look Box. I have often problems with old and destroyed heat-absorber-Plates over the central-tube.If it is brocken or damages, the heat of the exhaustsystem smelt the Plasic-tubes to the Look-Box , the air can´t get quick through.

Second:
Pull off the Diff-LookBox, it is fixed with two 6mm Screws. Take apart the upper cover , two more 6mm screws.Put it carefully off, without damaging the rupper-diaphragm ! There are no spare parts available for parts inside this Box! Only complett box.
Take apart the outside rupper gasget- it is fixed at the center-pin with a Plastic-ring. If this parts are damages, it can be orderd in factory.
Now pull of the rubber-diaphragm with his metall-pin.Check if the under-case and the metall-pin is corrosided and if it is "under oil" . Remove any oxid coat and befor connecting all parts ,grease them at all movement places. Check also the under-case , if it is oxided at the monting surface-here is a weak point -the case is near the tube outlet very small and it bend to leak.Check at both aluminium cover ,if the metall tubes are real fix mount( i have some break off) . At the upper cover is the main problem the carry out of the signal-cabel. There are two versions: first version breakthrough to the central rivet, second version a T-Tube is mount as breakthrough for the signalcabel and conecting tube for Unlooking . At both version are problems with sealing.Here, i think , you will have the problem.Seal it seperatly with liquid sealings.

Third :
check your four-wheel-drive valve if it workes corectly and it is seal?
The valve´s are under the middel dashbord cover . Also check if the Difflook filter and dryer is okay-they are under the glove compartment fixed at the frontwall.If you take apart the middle cover ,you shut clean in this way all tubes with pressured air.Sign all lines , remove all boxes and valves befor this.

If all this is without any success, you have to take apart the transmission.
If any Questions ,call me
Ugo
Posts: 91
Joined: Fri Apr 23, 2004 8:07 am
Location: Italy

Post by Ugo »

Thank you very much for the very complete explaination and hints.
It is clear that you have quite a deep experience in the TD Pinz - I wish I could live near your garage! Unfortunately, this is not the case.

I am now leaving for summer holydays. I will be back in one month and resume working on the Pinz.

Regards,
Ugo
Profpinz
Australia
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Joined: Sat Apr 17, 2004 7:08 pm
Location: Melbourne, AUSTRALIA
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Post by Profpinz »

I am now leaving for summer holydays. I will be back in one month and resume working on the Pinz.
Ugo, Ugo, I thought a Pinzgauer enthusiast such as yourself would spend his "summer holiday's" working on the Pinzgauer :D 8)
..... what more pleasurable way could you spend all that time!
Peter

1974, 712 6X6 Pinzgauer
1983, 710-1.6 4X4 Pinzgauer
1997, 718 6X6 Pinzgauer (in pieces)
1971, 700 Haflinger
1974, 703 LWB Haflinger
2001, Range Rover

http://www.ozpinz.com
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fesm_ndt
Posts: 252
Joined: Fri Jan 02, 2009 8:18 am
Location: Australia

Post by fesm_ndt »

Whats the default setting with the locks and all wheel drive selectors?

i.e. if you have insufficient vacuum do they engage or not engage?

My pinz is acting like the hanbrake is on, but isn't.

I think the locks are on, or perhaps just the front one as it lets go and then re-engages
Regards

Mike
(Project Gimpy 2)
Ugo
Posts: 91
Joined: Fri Apr 23, 2004 8:07 am
Location: Italy

Post by Ugo »

No vacuum = 4x4 engaged, front/rear difflocks disengaged.

Regards,
Ugo
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David Dunn
United States of America
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Joined: Wed Apr 14, 2004 7:08 pm
Location: Arcadia, CA

Post by David Dunn »

I need to check, but I'm sure it requires vacuum for both the 4x4 and the lockers to engage. The pneumatic/electric switches are: no power to engage the 4x4 ( hence engaging the 4x4 when engine is off and parked). Power engages the lockers. There is an innerconnect between the lockers. Rear locker must be engaged before the front will. Front locker will disengage if the rear locker is turned off. Also, 4x4 is automatically selected if low range is engaged.
Pg 16 to p 34 here.
http://f1.grp.yahoofs.com/v1/UHgZS_R7DX ... Manual.pdf

It really is a very simple and well thought out system... and the innerconnects keeps a driver from doing the wrong thing, and breaking something. :lol:
With that said, I did disable the 4x4 mode in low range so I could load it on a trailer. :roll:
.
The Trojan Horse... the 1st Pinz used to covertly carry troops into battle .




ATL Pinzgauer XM 718K TUM(HD) 6x6 FFR (aka The Green Grail)
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fesm_ndt
Posts: 252
Joined: Fri Jan 02, 2009 8:18 am
Location: Australia

hmmmm

Post by fesm_ndt »

yay i can log back in :D

Well had 4wd disengage on Saturday,

Whilst I was in the mud :(

I got towed out by a Pajero :cry: :cry: :cry: :cry: :roll: :oops: :oops:

I think I need to go through the whole check list
Regards

Mike
(Project Gimpy 2)
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David Dunn
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Post by David Dunn »

Well Mike,
Was it the 4x4 or the lockers? Still, the 4x4 operate with an open circuit, a bad power or ground wire wouldn't be a problem, but if it were the lockers, it could be.
On the 4x4 disconnection, first check under the truck, and make sure you didn'r pull a vacuum line loose ( on the lockers too).
I have a couple of other ideas where you may need to check, but I want to check the diagram of the innerconnects first.
.
The Trojan Horse... the 1st Pinz used to covertly carry troops into battle .




ATL Pinzgauer XM 718K TUM(HD) 6x6 FFR (aka The Green Grail)
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fesm_ndt
Posts: 252
Joined: Fri Jan 02, 2009 8:18 am
Location: Australia

Post by fesm_ndt »

G'Day Dave

yep 4x4. I need to go through the whole checklist (I should have done it last weekend but decided to go for a play)

I need to check the dash switches are plugged in correctly i.e. correct plug to correct switch then start on the checklist.
Regards

Mike
(Project Gimpy 2)
Ugo
Posts: 91
Joined: Fri Apr 23, 2004 8:07 am
Location: Italy

Post by Ugo »

Also check that the vacuum filter under the dash is not clogged. Check that you have no leaks in vacuum pipes at the 3 plenums under passenger side floor.
Check actual locks operation not trusting on telltales only (I had a bad contact in 4x4 lock, and telltale was always on even when 4x4 was not engaged).
You may wish to follow the manual check procedure step-by-step.

Good luck,
Ugo
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fesm_ndt
Posts: 252
Joined: Fri Jan 02, 2009 8:18 am
Location: Australia

Post by fesm_ndt »

G'Day Ugo

yep looks like Christmas weekend will be crawling over the pneumatics.

Hopefully on Sunday I can play in the mud.
Regards

Mike
(Project Gimpy 2)
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David Dunn
United States of America
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Location: Arcadia, CA

Post by David Dunn »

Mike, just to make you feel cheerier for the Xmas season.... be glad you're not hunting for air leaks on a Unimog 1300....they have more air lines in the cab than the Pinz has in it's entirety. :D
The hydraulic system of the 710/12s is simple, but the electro/pnuematic of the TDs was so well thought out. Just wish the dash parts were a little easier to pull.

When you lost your 4x4, did your lockers disengage also?

What can I say, I'm bored this week, and if I don't help you , I'll be picking on the gassers.... until my Cat parts get here :lol:
.
The Trojan Horse... the 1st Pinz used to covertly carry troops into battle .




ATL Pinzgauer XM 718K TUM(HD) 6x6 FFR (aka The Green Grail)
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fesm_ndt
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Location: Australia

Post by fesm_ndt »

G'Day Dave

yeah I think I lost the lot.

I will be studying the checklist for the rest of the week. I have to check the plugs are plugged into the correct switch also as were reinstalled by one of the guys. One of those things I typically like to photograph before being pulled out :?

as always joy, joy as if had nothing to do it would be boring...... however not having 4wd, in a 4wd is a nuisance
Regards

Mike
(Project Gimpy 2)
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David Dunn
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Post by David Dunn »

Hey Mike,
I was just reviewing the pneumatic and electric diagrams of the 4x4 and locker system.... a thing of beauty, simplicity, and logic :D
An open electrical circuit puts you into 4x4, and a closed circuit takes you out of 4x, and disconnects the vacuum to the front lockers ( never want 4x2 and both lockers).
The rear locker engages with a closed circuit whether in 4x2, or 4x4. But, a mirco switch at the rear control cylinder opens if the rear locker is off, disabling the front locker electrically .
Electric wise, all the relays and rockers switches are the same, only power is from pin 5 on the 4x4, and pin 3 on the lockers .

So, check to see if you have at least rear lockers.

Cheers
.
The Trojan Horse... the 1st Pinz used to covertly carry troops into battle .




ATL Pinzgauer XM 718K TUM(HD) 6x6 FFR (aka The Green Grail)
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