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Jaycar Speedo Correction Kits for GU

Posted: Sun Jun 12, 2005 5:33 pm
by JontyG
Hi all,

I am going to have a set of 315's fitted soon. I realise that this will put the speedo out, so I have been looking at options to re-calibrate it.

Probably the cheapest option will be the Jacar Speedo Correction Kit (~$50):
http://www1.jaycar.com.au/productView.a ... &SUBCATID=

Has anyone isntalled this? If so, does it work? How difficult is it to install?
Are there other preffered options?

Thanks,
Jonty

Posted: Sun Jun 12, 2005 6:47 pm
by krimnl
is your GU auto or manual petrol/diesel

i found on my GU when i changed from 3.9:1 gears to 4.3 gears with 315 tyres the speedo was 100% correct.
and it made the car so much more drivable. might be worth just going gears aswell if funds can stretch that far.

Posted: Sun Jun 12, 2005 6:55 pm
by JontyG
Mines a 4.8L auto. It has 3.5:1 standard. Any recommendations what I would need to change to? 4.1's have been suggested.

I gather this is a pretty expensive mod?

Posted: Sun Jun 12, 2005 7:01 pm
by krimnl
depending on what gears you use it might not be that expensive.
i would think 3.9's or 4.1's might fix your speedo.
and give you back some grunt , them ratios are the cheap ones.

some one will have a rear diff around with these gears you can borrow. all you need to do is install the rear center and take it for a drive testing it with a GPS. only takes an hour or so to change the rear to check which ratio suits best.

also being a 4.8 you can use GQ centers.

Posted: Sun Jun 12, 2005 9:38 pm
by JontyG
Thanks krimnl, thats good to know!

Posted: Mon Jun 13, 2005 10:09 am
by AndrewPatrol
Does that hour include setting up the pinion to run right on the ring gear teeth??????

Posted: Mon Jun 13, 2005 10:23 am
by bru21
just swap the hole 3rd member. might as well fit an arb while you are at it too. as with the 3rd out the hard work has been done. setting up the backlash couldn't be easier, especially if you use the hole member as then the pinion only has to be set in one plane. cheers bru

Posted: Mon Jun 13, 2005 8:35 pm
by krimnl
just bolt in the complete center.

sorry to take your thread of topic. i just believe your better of to correct the gearing than stuff round with the speedo.

Posted: Mon Jun 13, 2005 9:54 pm
by bru21
i think the jaycar is the best option if you run multiple sized tyres. i am going to run one of those boxes so i can switch between the 35's and 38.5's, just switch it on or bypass. i think 4.625s are about right for the 35's and 4.3's for 33's. gearing is good but you can't get 4.3's in reality (rare as) and the 4.625's will set you back close to 1k.

cheers bru

Posted: Mon Jun 13, 2005 9:54 pm
by JontyG
Thats cool...I'm just happy to get the feedback, and to hear what other options are available.

Posted: Tue Jun 14, 2005 11:11 am
by JontyG
I was qoted $750 to replace the front and rear ratios, fitment only. That means that I nee dto source them. Can anyone recommend the best place to look for 4.1's in melbourne?

How does that price sound for fitment?

TIA Jonty

Posted: Tue Jun 14, 2005 1:34 pm
by shortie
get a GPS. Accurate speed and can be used in any other vehicle.

Posted: Tue Jun 14, 2005 9:47 pm
by krimnl
JontyG wrote:I was qoted $750 to replace the front and rear ratios, fitment only. That means that I nee dto source them. Can anyone recommend the best place to look for 4.1's in melbourne?

How does that price sound for fitment?

TIA Jonty
i might have some centers around if you give me a call tommorrow i can have a look


Darren

Posted: Wed Jun 15, 2005 8:14 pm
by JontyG
Thought this site was pretty useful for calculating gear ratios, etc:

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