Patrol difflock
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supalot
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difflock
my patrol has vac difflock drops in straight away. no waiting at all
my patrol has vac difflock drops in straight away. no waiting at all
Re: difflock
Mmm ..... that's what I suspected should happen. Is that with the vehicle stationary or rolling slowly or either?
Tried it again yesterday, it took about 60 secs. After it's been locked once, it'll (sometimes) go in and out straight away - but then after driving for a while, it'll take another 60 secs to lock. This is a bit of a problem when you're out greenlaning in a group.
It might well be that I've got a hose leak - or a faulty actuator. On the other hand, the Patrol was 2 years old when I bought it - and I'll bet the locker wasn't ever used by the previous owner. Maybe it'll improve if I keep using it? Who knows.
The motor is still under warranty (until end July 2008) and I'll be taking it in for a service (18000 miles) around the end of Feb 08 - so if I'm still not convinced it's working as it should then I'll ask them to fix it under warranty. In the meantime, when we get a dry day, I'll have a grovel underneath and see if I can see a loose hose.
Cheers
Andrew
supalot said:
Mmm ..... that's what I suspected should happen. Is that with the vehicle stationary or rolling slowly or either?
Tried it again yesterday, it took about 60 secs. After it's been locked once, it'll (sometimes) go in and out straight away - but then after driving for a while, it'll take another 60 secs to lock. This is a bit of a problem when you're out greenlaning in a group.
It might well be that I've got a hose leak - or a faulty actuator. On the other hand, the Patrol was 2 years old when I bought it - and I'll bet the locker wasn't ever used by the previous owner. Maybe it'll improve if I keep using it? Who knows.
The motor is still under warranty (until end July 2008) and I'll be taking it in for a service (18000 miles) around the end of Feb 08 - so if I'm still not convinced it's working as it should then I'll ask them to fix it under warranty. In the meantime, when we get a dry day, I'll have a grovel underneath and see if I can see a loose hose.
Cheers
Andrew
I had a brief wander on a bit of unsurfaced carpark near home this afternoon. The first time, it locked in about 10 secs - which is fine. I then switched the lock off and drove around for a bit. Next time, it took over 60 secs. Maybe the second time it was affected by a little transmission wind-up.
If we get some nice weather (and if the mood takes me), maybe I'll put one side at the front on an axle stand and then jack up both of the rears under the diff. At least, that way I can guarantee there'll be no transmission wind-up. Like that, it should lock in around 10 secs or maybe less, I think. (The test in the workshop manual is for the actuator to operate in less than 10 secs with a vac pressure of 66.7kPa).
Cheers
Andrew
If we get some nice weather (and if the mood takes me), maybe I'll put one side at the front on an axle stand and then jack up both of the rears under the diff. At least, that way I can guarantee there'll be no transmission wind-up. Like that, it should lock in around 10 secs or maybe less, I think. (The test in the workshop manual is for the actuator to operate in less than 10 secs with a vac pressure of 66.7kPa).
Cheers
Andrew
The Troll has had two visits now to Westway Nissan in Stockort to try and fix the difflock. The first was in the week before Xmas. Basically, they didn't have a clue - apart from agreeing with me that it wasn't performing as it should. They said they were going to take advice from the Nissan techies on how to proceed.
It went in again on 4th Feb 08 (about 6 weeks after first reporting the problem!!). Westway have been given a fault finding procedure by Nissan
, which could take as long as 6 hours!! They rang me in the middle of the afternoon to say they'd fixed it. Apparently, the mechanic had followed the fault finding guide, thought he had discovered an electrical fault, cleaned up a connection, rolled it back and forwards a couple of times in the workshop - and the locker performed faultlessly. He pronounced it fixed. It took me less than five minutes to discover that it was still failing to lock most of the time. :roll: :roll:
After several more discussions on the phone with Westway, more advice taken from the Nissan techies they now want to have another go at diagnosing the fault. FWIW, I've now discovered exactly what is supposed to happen - in 4wd at less than 4mph (eg low 1st on tickover) when the locker is turned on, it should lock within one wheel rotation. If it doesn't, it's faulty. I took the Troll up to Harrop Edge Lane (unsurface track - in Oldham, a couple of miles from home) and trundled up and down in low 1st at tickover, trying to lock and unlock the diff. About a third of the time it locked virtually immediately; a couple of times it locked after 10 - 15 secs or so, but most of the time it hadn't locked after 40 secs, which is when I gave it up. :evil:
It's now booked in again for another fault finding session at Westway Nissan, Stockport on Thursday 28th Feb 08 (it's so far in the future, because that is when they next have a courtesy car available). 8O
I can see this becoming a marathon!!!! At least, they did confirm that it'll be done under warranty no matter how long it takes. I wonder if I'll have the Troll that long?
Cheers
Andrew
It went in again on 4th Feb 08 (about 6 weeks after first reporting the problem!!). Westway have been given a fault finding procedure by Nissan
, which could take as long as 6 hours!! They rang me in the middle of the afternoon to say they'd fixed it. Apparently, the mechanic had followed the fault finding guide, thought he had discovered an electrical fault, cleaned up a connection, rolled it back and forwards a couple of times in the workshop - and the locker performed faultlessly. He pronounced it fixed. It took me less than five minutes to discover that it was still failing to lock most of the time. :roll: :roll:
After several more discussions on the phone with Westway, more advice taken from the Nissan techies they now want to have another go at diagnosing the fault. FWIW, I've now discovered exactly what is supposed to happen - in 4wd at less than 4mph (eg low 1st on tickover) when the locker is turned on, it should lock within one wheel rotation. If it doesn't, it's faulty. I took the Troll up to Harrop Edge Lane (unsurface track - in Oldham, a couple of miles from home) and trundled up and down in low 1st at tickover, trying to lock and unlock the diff. About a third of the time it locked virtually immediately; a couple of times it locked after 10 - 15 secs or so, but most of the time it hadn't locked after 40 secs, which is when I gave it up. :evil:
It's now booked in again for another fault finding session at Westway Nissan, Stockport on Thursday 28th Feb 08 (it's so far in the future, because that is when they next have a courtesy car available). 8O
I can see this becoming a marathon!!!! At least, they did confirm that it'll be done under warranty no matter how long it takes. I wonder if I'll have the Troll that long?
Cheers
Andrew
Toolbox
Well-known member
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I take from what I read in your post Andrew that the locker should lock within one wheel rotation only if one wheel is rotating or one is rotating faster than the other.
If both wheels are rotating approximately at the same speed then the locker can not always engage straight away until the teeth line up inside.
Is this the way you tried it with a wheel spinning / slipping?
If both wheels are rotating approximately at the same speed then the locker can not always engage straight away until the teeth line up inside.
Is this the way you tried it with a wheel spinning / slipping?
Toolbox said:
I'm just quoting Nissan technical support.
In my experience so far, it either locks virtually immediately or within a second or two stationary or rolling slowly with no wheelspin - or it takes forever to lock or doesn't lock at all. Once or twice, it locked (after not locking for several seconds) when I turned the steering wheel a little in either direction. Most usually, though, it didn't have any effect.
Cheers
Andrew
The 'Troll went in to Westway Nissan in Oldham today to replace a glow plug (turns out there is one faulty one) - and to have another go at fixing the difflock.
Danny, the Nissan workshop manager seems bright and experienced - though has not worked on a Patrol difflock fault before. We went for a wander in the Patrol to check the locker on the nearest greenlane we could find. As expected (or rather as I hoped), it took ages to lock on the first attempt and didn't lock at all after that.
He rang me this afternoon, after doing a few basic checks. The electrics and controller are OK. The difflock vacuum solenoids are working fine. When the Patrol is on a ramp with the wheels free to rotate, the locker works perfectly, every time (they checked it about 30 times) - but with the wheels on the ground and moving slowly, it doesn't lock. Current thinking is that it's probably something sticking inside the differential itself. So ......... the 'Troll is stopping in overnight, hopefully the replacement glowplug will appear in the morning - and then Danny is seriously thinking of taking the diff to pieces.
We'll get there in the end ...........
Cheers
Andrew
(feeling hopeful)
Danny, the Nissan workshop manager seems bright and experienced - though has not worked on a Patrol difflock fault before. We went for a wander in the Patrol to check the locker on the nearest greenlane we could find. As expected (or rather as I hoped), it took ages to lock on the first attempt and didn't lock at all after that.
He rang me this afternoon, after doing a few basic checks. The electrics and controller are OK. The difflock vacuum solenoids are working fine. When the Patrol is on a ramp with the wheels free to rotate, the locker works perfectly, every time (they checked it about 30 times) - but with the wheels on the ground and moving slowly, it doesn't lock. Current thinking is that it's probably something sticking inside the differential itself. So ......... the 'Troll is stopping in overnight, hopefully the replacement glowplug will appear in the morning - and then Danny is seriously thinking of taking the diff to pieces.
We'll get there in the end ...........
Cheers
Andrew
(feeling hopeful)
Have they changed the oil in the diff? Just makes me wonder, as the obvious sometimes isn't considered. I know the LSD oil in Terrano's causes problems if it goes off, and the service interval is something like 24k, yet I do mine on an annual basis as it seems to go off really easily.
JonathanM said:
I guess it's still got the original oil in - it's not done 20K miles yet. It's an open diff, not a LSD, so maybe it won't go off as quickly. I did wonder about it though. I also wondered what the effect of having LSD oil in an open diff might be, if some loon in Japan happened to put that in by mistake when the motor was new. If they take the diff apart tomorrow, they'll be replacing the oil anyway.
I doubt that the previous owner had ever used the difflock - so, it's probably been just sitting around doing nothing for two years. I s'pose it'd be surprising if it worked perfectly after that.
Cheers
Andrew
I spent half an hour or so in the Westway Nissan workshop in Oldham this afternoon. They've checked it thoroughly.
With the 'Troll on a ramp with the wheels in the air and the engine running, in 4wd neutral - if you try to lock the diff then it either locks or it doesn't (obvious, eh?). If it locks then you can lock and unlock it as frequently as you like - and it'll do it immediately. If it doesn't lock then it will never lock unless you rotate the rear wheels. If you rotate them together, it does not lock. If you rotate one a little more or less than the other, it will lock immediately. This is exactly what it's supposed to do. Practically, the locker is only needed when there is a wheelslip anyway, so in the real, it should work fine.
As they've never done any fault finding on a 'Troll difflock before, Danny was keen to learn from the fault finding process. He's checked out the vacuum solenoid valves, they are opening and closing exactly as they should. He's tested using a vacuum gauge on the rubber hoses that connect to the actuator on the diff. He's also verified the action of the actuator by manually applying suction using a hand vac-pump. All worked fine.
Earlier on this afternoon, he removed the diff and had it on a bench when I arrived, so that we could see how it worked and be sure there's nothing amiss inside the diff itself. Looks fine. He's ordered new gaskets and O-rings and stuff, so that he can put it back together again in the morning.
As of now, everything is fixed and working fine. :smile:
With the 'Troll on a ramp with the wheels in the air and the engine running, in 4wd neutral - if you try to lock the diff then it either locks or it doesn't (obvious, eh?). If it locks then you can lock and unlock it as frequently as you like - and it'll do it immediately. If it doesn't lock then it will never lock unless you rotate the rear wheels. If you rotate them together, it does not lock. If you rotate one a little more or less than the other, it will lock immediately. This is exactly what it's supposed to do. Practically, the locker is only needed when there is a wheelslip anyway, so in the real, it should work fine.
As they've never done any fault finding on a 'Troll difflock before, Danny was keen to learn from the fault finding process. He's checked out the vacuum solenoid valves, they are opening and closing exactly as they should. He's tested using a vacuum gauge on the rubber hoses that connect to the actuator on the diff. He's also verified the action of the actuator by manually applying suction using a hand vac-pump. All worked fine.
Earlier on this afternoon, he removed the diff and had it on a bench when I arrived, so that we could see how it worked and be sure there's nothing amiss inside the diff itself. Looks fine. He's ordered new gaskets and O-rings and stuff, so that he can put it back together again in the morning.
As of now, everything is fixed and working fine. :smile:
