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Speedo correction

Posted: Sun Jul 17, 2005 9:07 pm
by AFeral
Finally put some 35s on my patrol :) :)
Only problem speedo seems a bit ????? all too shit.
Is there any way to sort this out?
To do 80 km an hour what speed does the speedo need to be at. Whats the go for 60 and 100 too.
Thanks.

Posted: Sun Jul 17, 2005 9:20 pm
by JontyG
you can either get a speedo correction device from Jaycar, or Marks 4wd
(http://www.marks4wd.com/speedo-correction.html)

or, you can change the diff ratios...check out the following link to estimate the ratios that will bring it back to standard:

http://members.optusnet.com.au/~zerosin/gearcalc.html

FYI, i have a 4.8 GU, with 3.5:1 diff ratios and 315's, and my speedo is approx. 15% out. I am changing the diff ratios, cause it will improve the driavability offroad, and bring the speedo back to standard.

the seedo correction device (as sold by MARK'S) is good if you are switching btwn different size tyres on a regular basis.

Hope this helps,
Jonty

Posted: Sun Jul 17, 2005 9:21 pm
by Bartso
apparently fitting 35's puts speedo out by 16% so dash reads 100 your really doing 116
Jonty just beat me to it

Posted: Sun Jul 17, 2005 9:24 pm
by blkmav
Didn't Bazzle once say something about just changing the cog in the speedo?

speedo

Posted: Sun Jul 17, 2005 10:01 pm
by china
i got 36inch pedes on mine an is only 10% out, unless the GPS shows an incorrect speed??

Posted: Sun Jul 17, 2005 10:05 pm
by turps
blkmav wrote:Didn't Bazzle once say something about just changing the cog in the speedo?
Yep can buy the gears for bugger all from Nissan and supposedly they are easy to change. I never worrid about it as the 33's roadies where close enough and when the 35's are on I always use teh GPS as a speedo.

Posted: Sun Jul 17, 2005 11:08 pm
by holeyhardtop
http://www.outerlimits4x4.com/PHP_Modul ... correction

the above link will give you all the info required. i changed mine when i fitted 33"tyres to my gq. you'll need a small pin punch{about 1/16" dia} to knock out the retaining pin on the gear, tis a bit fiddly but nothing a person with a brain and mild dexterity can't easily achieve. can't remember the cost for the gear but $40ish rings a bell, either way it's a s#it load cheaper than a fine down here in the revenue state.

Posted: Mon Jul 18, 2005 9:23 pm
by vcharter
all ya need to do is adjust tuning pod in speedo head itself ,remove outer cover of dash cluster and drill small hole inline of adjustor and adjust to suit,best way of getting it accurate is gps

Posted: Mon Jul 18, 2005 10:37 pm
by fatcatsam
so, if i have gone from 265/70r 16lt to 33" MTR's, what percentage has my speedo gone out?

Posted: Mon Jul 18, 2005 10:41 pm
by bogged
I just drive with GPS on dash now.. its easier. arseholes to the bacon

Posted: Tue Jul 19, 2005 7:12 am
by JontyG
fatcatsam, checkout the following link, as mentioned in my first reply:

http://members.optusnet.com.au/~zerosin/gearcalc.html

Posted: Tue Jul 19, 2005 10:38 pm
by AFeral
Thanks for the help think i will go the hole and the screw driver option. Will be changing the diff ratios before long with any luck. So i can change it back after.

Posted: Wed Jul 20, 2005 8:09 am
by fatcatsam
JontyG: Thanks, missed it before