Rear wheels locked

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spandit
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Rear wheels locked

Post by spandit »

Moved house recently and since Pinz was non runner, had to get it recovered there.

When the guy turned up to winch it into a flatbed, the rear wheels wouldn't turn. Handbrake was off (like it could have held that much force anyway!) and none of the lockers were engaged. Clutch was in and gearbox in neutral.

I've jacked her up at the back now & wheels turn in opposite directions (as I'd expect from a differential) so brakes aren't stuck on.

Any ideas? It had been sat for quite a while out of doors...
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Robin

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Stekay
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Re: Rear wheels locked

Post by Stekay »

Just as an additional point of diagnosis, try putting the transfer case in neutral and let us know if that allows the driveshaft to turn.
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undysworld
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Re: Rear wheels locked

Post by undysworld »

More importantly, put the tcase in neutral and see if the rear wheels turn.

Unless the transfer case somehow got locked up, I'd think it has to be the e-brake. I'd think that could easily account for the rear end being locked up. It sort of a double disc brake back in there. Maybe bang a bit on the lever and case and see if you can knock things loose inside.
spandit
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Re: Rear wheels locked

Post by spandit »

The handbrake can barely stop the Pinz from rolling uphill, how is it going to counter a 9-tonne winch? I have hammered on the lever, as it happens.

Would the wheels still turn if the handbrake was on? I'm pretty sure I had the TC in neutral too. How am I going to turn the driveshaft without a running engine?
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Jimm391730
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Re: Rear wheels locked

Post by Jimm391730 »

Would the wheels still turn if the handbrake was on?
Yes - the handbrake locks the driveshaft, but without the lockers applied then one wheel can rotate forward while the other rotates backwards (differential action). If you REALLY want to ensure that the wheels won't turn when the handbrake is applied then you need to engage at least the rear locker.

So it sounds like the driveshaft won't turn. I can't imagine that the transfer case could have gotten locked, so I'm 90% sure it is just the handbrake has frozen in place after sitting for so long... Was the handbrake applied during the sitting? If so, that's a dead giveaway that it's the hand brake that's frozen. Put the transmission in neutral and the transfer case in low range, and work the exposed driveshaft back and forth to see if you can free the handbrake.
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spandit
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Re: Rear wheels locked

Post by spandit »

Might have to dismantle the handbrake. Pretty sure I hadn't left it on but you could be right, thanks. I'll give it a try
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Jim LaGuardia
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Re: Rear wheels locked

Post by Jim LaGuardia »

Use a deadblow hammer to un-stick the parking brake(smack the tail cone, tap the mechanism), very common in moist conditions over time.
Rear locker is directly splined to the driveline, if the brake fails to release the vehicle will not move.
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spandit
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Re: Rear wheels locked

Post by spandit »

Sorry to drag up an old thread but with the rear end jacked up, the wheels turn freely (in opposite directions, as you'd expect with a diff) but won't turn together - does this mean the centre diff is locked? Would disconnecting the cardan shaft help me push the Pinz into the bay in my barn where it is supposed to be?
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Haf-e
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Re: Rear wheels locked

Post by Haf-e »

There is no center diff on a pinzgauer - just the rear and front diffs - it sure sounds like your e-brake is locked up - or probably - rusted up.

If you put the tranny and t-case in neutral then you should be able to spin the short cardan shaft by hand... disconnecting it won't help anything.

Its not that hard to disassemble the e-brake - but I would try a dead-blow hammer if you have one - or a big chunk of firewood if you don't...

You could also pull one of the rear wheels off (passenger side) and sit in the driver seat and have someone pull or push it on three wheels to get it into the shop - should work since the pinz is pretty nose heavy.
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spandit
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Re: Rear wheels locked

Post by spandit »

So the wheels would still turn with the brake on? I know it acts on the driveshaft. I have tried smacking it - I might have to give it another go or look at dismantling
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Jimm391730
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Re: Rear wheels locked

Post by Jimm391730 »

with the rear end jacked up, the wheels turn freely (in opposite directions, as you'd expect with a diff) but won't turn together - does this mean the centre diff is locked?
Since the wheels only turn in opposite directions because of the differential action, this means that the drive shaft is not turning. This could be because of a stuck E brake, the transmission and transfer case are in gear, or the front axle is engaged (4x4 lever) or the dog is stuck. Since both front wheels are still on the ground then the central drive shaft cannot turn; if the dog is engaged or stuck then the rest of the drive shaft cannot turn, either. This will happen even if the transfer case is in neutral.
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spandit
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Re: Rear wheels locked

Post by spandit »

By "dog" you mean the bit that engages front wheel drive? How can I manually free this if it's engaged?
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edzz
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Re: Rear wheels locked

Post by edzz »

jack one front wheel up if it can turn that rules out 4x4 issues. my vote is for the parking brake being locked up, until it is ruled out that's where I'd be concentrating my efforts.


EDIT: Assuming that the truck rolled before it was left to sit and now the truck is in neutral (5 speed box, reduction box or both) the only thing that commonly causes problems you describe are brakes swelling and rusting in place. I haven't had this issue on my Pinz however I've dealt with it on other trucks.
Last edited by edzz on Tue Oct 28, 2014 1:00 pm, edited 2 times in total.
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undysworld
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Re: Rear wheels locked

Post by undysworld »

Jimm391730 wrote: This could be because of a stuck E brake, the transmission and transfer case are in gear, or the front axle is engaged (4x4 lever) or the dog is stuck. Since both front wheels are still on the ground then the central drive shaft cannot turn; if the dog is engaged or stuck then the rest of the drive shaft cannot turn, either. This will happen even if the transfer case is in neutral.
Jimm,
I assumed that the front wheels would turn and only the rears would not:
When the guy turned up to winch it into a flatbed, the rear wheels wouldn't turn.
In which case, I don't think that the front axle being engaged is the problem. ?? If it was engaged, then all four should have either rolled (or not rolled) when they tried to load it.

Yes, what Edzz just wrote is the same idea. I also think it's e-brake related.

Edit: Is it possible for the output shaft of a t-case to lock up, without other symptoms such as the front output or propellor shaft input also locking up? I'd think not, but... ???
spandit
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Re: Rear wheels locked

Post by spandit »

When it was towed onto the flat bed, the front wheels turned but the rears didn't - the handbrake is lousy at the best of times, I don't know how it could remain engaged whilst both rear tyres were dragged over concrete
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