Working out diff ratios

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Bre
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Working out diff ratios

Post by Bre » 16 Jun 2017 17:17

Kan van die slim manne my laat weet of ek op dies regte pad is asseblief? Ek wil my diff ratio kry so dat ek weet of ek 285/75R16 bande kan op sit.

Ek het opgelet dat die speedometer omtrent 10% uit is wat my laat dink ek het nie die oorspronklike 4.111 diff in my 4500 GRX het nie. Of is die speedometer net uit en klaar? En by so baaie?

In elk geval, om my diff ratio te kry het ek een van die agterwiele afgehaal, 'n merk op die rotor gemaak en 'n merk op die propshaft flange en die wiel gedraai. Sewentien draaie van die wiel gee my amper presies 37 draaie op die diff. Omdat die een wiel op die grond is kry die eene wat ek draai al die krag en nie halfte nie, so ek moet halfte van die wiel se rotasies wat, of hoe?

As dit korrek is kry ek 37 ÷ (17 ÷ 2) wat my 4.353 gee. Die naaste ratio is 4.375 wat omtrent 6.42% groter is, en nie die 10% wat die speedometer uit is nie. Miskien is die speedometer maar net uit, maar net nie by 'n hele 10% nie?

Dus te sê, vir 285/75R16 bande makeer ek 'n 4.41 diff ratio, maar 4.375 is seker naby genoeg? Dit is as my somme korrek is.

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Re: Working out diff ratios

Post by Tinus lotz » 16 Jun 2017 17:48

4.5 handrat loop mooi met 33

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Re: Working out diff ratios

Post by Peter Connan » 16 Jun 2017 17:51

Ek dink nie daar is 'n 4.41 nie?

Elk geval, meeste ouens is heel gelukkig met 4.111 en 285/75 R16's, so 4.375 is reeds 'n verbetering.

Meeste karre se speedos lees onder, en 10% is nie buitensporig nie. Ook raak die fout tipies groter met slytasie. Ek het eens op 'n tyd 'n kar gehad wat 160 gese het op 120...

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Re: Working out diff ratios

Post by TijmenvdS » 16 Jun 2017 19:57

Ek is redelik seker dat hy nog die oorspronklike diff ratios in het. Ek het ook gehoor van die speedo wat uit is en het dit maar so aanvaar. As die groen meneer 4.3 ratios in gehad het sou hy vreeslik hoog gerev het op spoed en ek het gevind hy is heel normaal. As ek reg onthou het hy hier by 2800 rpm se kant op 120 gedraai en dit is die selfde as wat die diesel doen wat ek nou het ongeveer en hy is ook veronderstel om 4.1 in te hê. Maar daar is vreeslik baie 4.5s met die 285s op en die wat ek mee gekuier het is heel gelukkig. Oom Ossewa, David M, Grahm Cummings en paar ander wat ek ongelukkig nie hul name kan onthou nie. Ek sal sê go vir dit. :blonde:
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Re: Working out diff ratios

Post by SJC » 16 Jun 2017 20:30

Cant commend on how to calculate the ratio, but afaik all 4.5's got 4.1 ratio diffs...
Is yours auto or manual? I think the 4.5 auto box battles a bit with 33" wheels.


GQ 2.8 Diesel = 4.625:1
GQ 3.0 Petrol = 4.11:1
GQ 4.2 Petrol auto = 3.9:1
GQ 4.2 Petrol manual = 4.11:1 or 3.9:1
GQ 4.2 Diesel = 4.11:1
GU 2.8 Diesel = 4.625:1
GU 3.0 Turbo diesel auto = 4.375:1
GU 3.0 Turbo diesel manual= 4.11:1
GU 4.2 Diesel = 4.11:1
GU 4.2 Turbo diesel (wagon) = 3.9:1
GU 4.2 Turbo diesel (ute) = 4.11:1
GU 4.5 Petrol = 4.11:1
GU 4.8 Petrol manual = 4.375:1
GU 4.8 Petrol auto = 3.54:1
Please check you compliance plate - example below
HG41 = 4.11:1 - H233 Front & Rear
HH41 = 4.11:1 - H233 Front & H260 Rear

http://www.marks4wd.com/diff-ratio-information

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Bre
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Re: Working out diff ratios

Post by Bre » 17 Jun 2017 12:45

Thanks for the feedback guys and it is a manual Fanus.

Sounds like 285/75R16s won't be too much of a problem then. Now the question is General Grabbers ATs or BFGoodridge KO2s :think:

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