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Nissan Urvan / Caravan
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You seem to have the opposite problem. At an indicated speedo speed of 100kmph, my van is really travelling at about 87kmph.

Nissan NZ advise they use the maximum Australian Design Rule permitted variation, which I think from memory is 10% plus 5kmph, as it encourages drivers to drive more slowly (but also flatters mpg, noise, frequency of service and earlier disposal).

When car manufacturers started fitting GPS, the GPS and speedo reading (and odo too), would disagree.

Now fitted GPS units supplied complete with the car are already 'corrected' to mirror an over reading speedo, so both should be consistent. Use an aftermarket GPS to see how much they are really out.
 

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You seem to have the opposite problem. At an indicated speedo speed of 100kmph, my van is really travelling at about 87kmph.

Nissan NZ advise they use the maximum Australian Design Rule permitted variation, which I think from memory is 10% plus 5kmph, as it encourages drivers to drive more slowly (but also flatters mpg, noise, frequency of service and earlier disposal).

When car manufacturers started fitting GPS, the GPS and speedo reading (and odo too), would disagree.

Now fitted GPS units supplied complete with the car are already 'corrected' to mirror an over reading speedo, so both should be consistent. Use an aftermarket GPS to see how much they are really out.
Yes that is exactly what I do, use the GPS, and have checked against two GPS at the same time to compare accuracy between them.

Most of the Patrols will be reading under because of increased tyre diameter.

Fo me, running bigger tyres, at a speedo reading of 100km/h I am actually doing 106km/h so have to be really aware of the difference. The boys in blue over here do not seem to care about the Australian Design Rule permitted variation, 5kmph over at 100. They will happily give a ticket for 2 or 3km over as they say their new lasers are that accurate and we should compensate to drive under the limit and account for the potential 5km/h variation.

Over Easter they also hand out the added bonus of Double Demerrit Points. Another good reason to have the speedo correct and keep the speed under control.
 

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GUII ZD30DI Wgn
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This is a great read, thanks for bringing it out of retirement, it's now linked in the General Patrol Discussion archives under Modifications.
 

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I think 18 is blue, that is what was in mine originally with the stock 275/65/17 ZD30 Auto 4.3 diff gears
Just checked and I can confirm blue is 18 teeth, mine came out of a '98 GU rd28eti gearbox.

Looks like they are also colour coded, so it might be worth filling in the gaps for easy identification.

??????-VB014 14 Teeth-Off White
32743-VB015 15 Teeth-?
32743-VB016 16 Teeth-Bright Yellow
32743-74P17 17 Teeth-Black
32743-74P18 18 Teeth-Blue
 

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nissan patrol
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Mine is the opposite to NZUrvan. When my speedo is showing 100, according to 4 different devices (not just programs, 4 different pieces of equipment) I'm going ~103kph. But it varies.

60=62
80=83
90=94
100=103
106=110!!!

No greater than, really?!?

And yes, I'm running 275/65R17 as per the placard.

I've been keeping my eye on this thread for quite some time!!
 

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nissan patrol gu4 wagon
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Mine is the opposite to NZUrvan. When my speedo is showing 100, according to 4 different devices (not just programs, 4 different pieces of equipment) I'm going ~103kph. But it varies.

60=62
80=83
90=94
100=103
106=110!!!

No greater than, really?!?

And yes, I'm running 275/65R17 as per the placard.

I've been keeping my eye on this thread for quite some time!!

This is about the same as mine was when it was in standard form.
 

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Nissan Urvan / Caravan
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I presume if your speedo reads lower than your actual speed, it's because you are running bigger wheels.
I looked at fitting larger wheels to the van. But here, they cannot protrude beyond the arch, and more importantly, the tyre rating must match or exceed the vehicle GVW.

Urvan GVW is 3,100kg, so minimum tyre weight rating is 725kg.

The vehicle safety gurus in the EU are currently advocating prohibiting certain mods on vehicles (including wheel and tyre changes unless the manufacturer offered those as standard or options on new vehicles), as well as mandatory seatbelt and airbag replacement.

Aftermarket parts manufacturers, car clubs and others are up in arms, because at least 20% of EU loony ideas become law (like permitted banana curvature).
 

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Bit of a thread dig but ive just put 4.1 gears out of my gq into my gu that had 4.3s can I use the speedo gear from the gq are they the same the gu has stock tires
 

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Bit of a thread dig but ive just put 4.1 gears out of my gq into my gu that had 4.3s can I use the speedo gear from the gq are they the same the gu has stock tires
I would say try it first with the diff and tyres you want to run, then see how far the speedo is out against GPS and go from there.
Once you work that out then see what cog you have and compare with the GQ one to see if it has more or less teeth. you might be lucky and be able to swap.
 

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Bit of a thread dig but ive just put 4.1 gears out of my gq into my gu that had 4.3s can I use the speedo gear from the gq are they the same the gu has stock tires
I know the gu rd28ti gearbox uses the exact same speedo sensor as the gu td42t gearbox (completely different gearboxes. The whole speedo sensor is interchangeable, not just the gear. So I would assume that they wouldn't bother changing it between gq and gu (especially if its both td42 gearboxes), so it should simply bolt up no dramas.
 

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I purchased the necessary parts from Nizzbits - no issues getting them. Replaced the black 17 tooth with a 15 tooth. 285/70R17 tyres. Speed is pretty close at lower speeds but by 100kmh on the speedo only doing 95. Should never get a ticket.

If I change from 4.1 to 3.9 diffs is this going to make it more accurate or worse again?

??????-VB014 14 Teeth-Off White
32743-VB015 15 Teeth-Brown
32743-VB016 16 Teeth-Bright Yellow
32743-74P17 17 Teeth-Black
32743-74P18 18 Teeth- Blue
 

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nissan
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going to 39 should slow car down in speed but speedo will read the same
so speedo will read faster than yr going

most factory cars these days are not allowed to read slower than actual speed
it used to be + or - 2 km leeway

but now the speedo can only read faster than actual speed

ive seen Toyota aurions 5 kms faster on speedo
mazda 3 read 6 or 7 kms faster on speedo
ve commodores read 4 km faster

so next time you go down freeway and a lot fo people are driving 5kms slower
and you like to drive on the limit or 2 kms over and a lot of normal people are driving slower
its cause they don't realise the speedo is not perfectly accurate and they thing they r doing 100
when they are doing closer to 90

if u chop and change diffs or wheels all the time its easier to fit a correction box
where u can adjust it in the cabin with a turn of a screw
 

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I know the gu rd28ti gearbox uses the exact same speedo sensor as the gu td42t gearbox (completely different gearboxes. The whole speedo sensor is interchangeable, not just the gear. So I would assume that they wouldn't bother changing it between gq and gu (especially if its both td42 gearboxes), so it should simply bolt up no dramas.
GQ and GU do run a different speed sensor I believe GQ's make 16 pulses per revolution and GU's make 8 pulses per revolution. I have encountered this first hand when fitting a GQ 5 speed to my GU when doing my engine conversion where my speedo is reading double what it should. They look to be interchangeable with each other ill find out in the next couple of weeks when I change it.
 

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GQ and GU do run a different speed sensor I believe GQ's make 16 pulses per revolution and GU's make 8 pulses per revolution. I have encountered this first hand when fitting a GQ 5 speed to my GU when doing my engine conversion where my speedo is reading double what it should. They look to be interchangeable with each other ill find out in the next couple of weeks when I change it.
Handy to know...
 

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yea i tried getting the 1 of the gq its stuck hard tried levering tried twisting with a shifter ended up snapping the whole sender off flush with the box, hasnt come out in 26yrs id say
 

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yea i tried getting the 1 of the gq its stuck hard tried levering tried twisting with a shifter ended up snapping the whole sender off flush with the box, hasnt come out in 26yrs id say
OOPS, did it have a bolt holding it in on one side like the GU ones do? I wonder if older ones were held in differently with a clip or something else. But then 26 years stuck in the same spot, that would be well and truely glued in place.
 

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yea took the bolt out tried levering it out gave it quite a few love taps it twisted about 10mm tried to pry from the tab that the bolt goes through snapped it off then tried hitting the sender up and down just snapped it flush at the box dosnt really worry me as box will probably be going to scrap metal just want the gear out of it
 

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Checked my 2001 GU td4.2t wagon and its got the yellow 16 teeth, running 33's so will be getting the 15 teeth gear. 3 minute job to get out. And a small amount of fluid leaks out as already mentioned.

Have already got fined due to the speedo inaccuracy so if anyone's thinking about getting it done is say do it as the fine costs double what the install/ parts cost would be.
 

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Hey guys , went to nissan but they reckon there's none is Australia.
Is there somewhere else I can get these babies from?
Cheers
Booy
 
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