Changed diff, speedo not reading correct

[Lex]

Hi
I have a vt v6 auto Commodore with 3.46.1 diff & 235 x 35 x 19" wheels.
Now speedo is not reading correctly.
I have been to Mechanics to have them change the pulse count on cluster.
But they do not know the correct count.
Does anybody who has done the diff upgrade know what the pulse count is?
Thanks if anybody can help.
Lex

 

[axemurderer101]

i got mine done by holden, there wont be a set value to change to. I think they just drive around with a gps and adjust the count until it matches.

 

[NeddyBear]

Do you know roughly how much the speedo is out by? if not easiest way is via the an App on the phone and then correct the reading via the thiny on the dash. That's how we did ours after changing over to 16'' rims and HP tyres.

 

[Towcar]

I found the count for the 3.46 and 235/45/17 rims on here somewhere. Worked a treat bang on.

Except the little x on the cluster since the change was made!

 

[Lex]

Do you know roughly how much the speedo is out by? if not easiest way is via the an App on the phone and then correct the reading via the thiny on the dash. That's how we did ours after changing over to 16'' rims and HP tyres.

Hi Neddy
Whats a thiny on the dash?
Speedo is out by 10km @ 60km & 15 km at 100km.

 

[Lex]

Hi
I found this on the net.
From snap on tools.
Hope this can help other people.
Lex

 

[Lex]

Hi
With that list of pulses from Snap on tools, l took to my mechanic.
For me 6800 pulses gives me correct speedo reading.
Before diff change, @ 60 kmh by speedo gps would read 57 kmh.
Now @ 60 kmh by speedo reading, gps reads 58 kmh.
I like.
There is no x in any of the windows either.
Hope this helps
Lex

 

[Husky]

All you do is take the current PPK, divide it by the old ratios (probably 3.08) and then multiply it by the new ratio. I did this whe I fitted 3.46 gear to my VX using my tech 2 and have had no issues. speedo is spot on.

 

[Lex]

All you do is take the current PPK, divide it by the old ratios (probably 3.08) and then multiply it by the new ratio. I did this whe I fitted 3.46 gear to my VX using my tech 2 and have had no issues. speedo is spot on.

Hi Husky.
What is ppk?
Lex

 

[Immortality]

Pulses Per Kilometer