4.6 diffs v 4.3

[jmd235]

I have 2 x D22's both ZD30's one with 4.6 diffs [ according to the compliance plate] and 1 with 4.3 diffs, also my brother has one with 4.6 diffs. The performance difference is great between my 4.3's and both those with 4.6's. I do realise there should be some difference but i am unsure if the difference is that great or i have a problem with the one with 4.3's . Any ideas?

 

[tweak'e]

what engines do they have and what year where they made?
diff ratios really only changed when new engines where released. so you can't really compare them side by side.
the odd one out is 2008 yd25.

 

[jmd235]

All 3 are ZD30's both with 4.6 diffs are 2002 models and stock standard and the 4.3 is an 05 model with a 3" exhaust , EGR and buttifly mod, otherwise standard.
All have the same size tyres. Compared to the 2002 models the 05 seems like it isn't boosting but the gauge says 16lbs booost. I am starting to think there is something wrong with it

 

[tweak'e]

i'll have to go check but 4.3 should be stock standard.
afaik no diff ratio change in zd30 models.

a 4.3 will be slower than a 4.6. there should be a noticeable difference in rpm at 100km/h between the two.

 

[OneMofo]

what engines do they have and what year where they made?
diff ratios really only changed when new engines where released. so you can't really compare them side by side.
the odd one out is 2008 yd25.

Why is the 08 2.5 the odd one out?? Just asking as that's what I have.

 

[jmd235]

They all seem to do around 2500rpm at 100 K's. So you are saying they should all have the same diff ratio? I thought the CA43 or CA46 on the compliance plate indicated diff ratio? If they are all the same then i definitely have a problem with the 05

 

[shaggy]

I also have a 05 model nav I will have a look at my plate but pretty sure my ratio is 4.3

 

[tweak'e]

They all seem to do around 2500rpm at 100 K's. So you are saying they should all have the same diff ratio? I thought the CA43 or CA46 on the compliance plate indicated diff ratio? If they are all the same then i definitely have a problem with the 05

i would say its the same ratio unless theres a weird aussie only version.
i'm not up on plate numbers.

 

[tweak'e]

Why is the 08 2.5 the odd one out?? Just asking as that's what I have.

afaik when they changed to the YD25 engine in 08 they kept the same ratio as the earlier zd30, but changed it to a lower ratio in 09.

 

[OneMofo]

Ahh that would explain a lot actually. 08 sucks balls off road since I locked the front.

 

[jmd235]

Ok i have exhausted my search effort here and google. It would seem the ZD30's were all 4.3's although i don't understand why there is different trans codes on the compliance plates. Therefore i need to start looking at why my 05 model is such a slug. On hills around my place that i need to go back to 4th and sometimes 3rd in it i can go up in 5th in the others without a problem.
Any ideas where i should start looking?

 

[Rumpig]

Ok i have exhausted my search effort here and google. It would seem the ZD30's were all 4.3's although i don't understand why there is different trans codes on the compliance plates. Therefore i need to start looking at why my 05 model is such a slug. On hills around my place that i need to go back to 4th and sometimes 3rd in it i can go up in 5th in the others without a problem.
Any ideas where i should start looking?

Sucking air at the fuel filter.
neutral position switch.
Got boost?
They all got the same size tyres?

 

[jmd235]

Yes they all have the same size tyres, boost guage says 16lbs boost[ although unlike the other 2 you can't feel boost] and i don't think it is sucking air at the fuel filter , Moving the gearstick doesn't do anything so unlikely nuetral position switch

 

[dilmah]

My 08 YD25 D22 had 4.375's as the stock ratio, front has been regeared to 4.88 and the rear is 4.90. These ratios are ideal for running 35" - 37" inch tires but are a little underdone for 33's. Id suggest a 4.6 ratio for 33" - 35" tires

 

[Rumpig]

Check the shutdown and egr butterflies and make sure they work properly, might be chocking the engine.

 

[Dion]

The compliance plate doesn't lie, if it's CA43 then the rear diff is a C200, the front is an R180a, and the ratio is 4.3.

 

[jmd235]

So if the compliance plate says CA46 than it should be 4.6 correct?

 

[Dion]

Yes correct.

 

[ericcs]

if your still unsure, mark the rear brake drum and backplate at the same spot. then mark the rear tailshaft yoke and the diff housing at the same spot. spin the brake drum 1 revolution and count how many times the tailshaft turns. should notice the difference between 4.3 and 4.6 revolutions

 

[jmd235]

So i assume 5th gear must also be different as well as they run the same revs at 100Ks