Hello

This is my first post. I'm from europe (scandinavia) but easily its the australian market that has the most experience with patrols. I have not found exactly the answers on route to go for 4.88 gears. So therefore i'll ask here for more information.

My 2006 Gu4 zd30Di Auto has gone 280.000km and i bought it a year ago. It was very slow and like in limp home mode all the time. Only recently i installed Tillix and Dawes kit, egr delete, removed the oil breether pipe from intake. After adjusting the boost and spoolup, peaking at 17 psi, and changed fuel filter and oil/filter, the engine is transformed. Going from a snail to become at least a 150hp engine by the feel of it. All thanks to whar i learned on the forums.

Fuel consumption gone way down from 1.2 to 0.9 in general. Last trip 0.85! 

So to the issue in hand. Gearing. All i read Is gearing and revs at 100 kph. In my country max speed is 80kph. And mostly the traffic sits at 70-75kph. I have 32" tyres for now, but planning to go up to 33" soon. The problem with the speed we are travelling at, 4th gear rearly ingages, and lockup 4th almost never, as it locks up at 82-85 kph.

For my conditions, would 4.88 gears be to low or just perfect? Can anyone confirm revs, drivability, fuel consumption and so on with zd30 and 4.88 gears? If so, just drive at 80 kph for a day just to inform me back, that would be appreciated

the next thing would be a lockup controller kit. What do you think? Is this neccesary?

 

 

7 hours ago, KnotGU said:

The problem with the speed we are travelling at, 4th gear rearly ingages, and lockup 4th almost never, as it locks up at 82-85 kph.

The torque converter lock up issue is easily fixed, searched for it on Patrol forums it is very easy mod....

https://www.mypatrol4x4.com/topic/226-patrol-torque-converter-lockup-override-system/

 

As to what 4.88 gears is I have no idea but I wouldn't change diff ratios as going higher would only increase revs and fuel consumption though it would give you more torque/power at the expense of speed. 

Regards

Edited April 21, 20251 yr by Rumcajs

Thank you for the answer.

Should be easy to follow installation in that thread for lock up kit. I read it disingeages at 55 kph, wich makes it not so useful in my case. Better to skip this for now and only go for the gearings?

I do understand that general conclution of lower gearing = lower top speed and more fuel consumption. But in my case i disagree with that. Mostly the speeds here are 50-65 kph. Only the highways are 80. So i practically have a 3 speed auto. With o/d off the revs are higher in 80 with my standard 4.37 gears, than it would be in 4th gear (o/d on) in 80 with 4.88 gear. Combined with a engine that pulls easier, i think my consumption would actually go down. If i regularly drove at 120 kph the calculation would of course been different.

Compare it to a manual, that we know have lower consumption than an auto, the manual has shorter gearings between 1 to 5th, closer ratios. My guess is that this would remind of an auto only with lower diff gear ratios than standard.

As for now, i feel the engine and auto pulls uneccesary heavy in my daily 1 to 3rd gear driving. For example it pulls to 80 kph in second gear, why? Why this long diff ratios.  So if enyone with a 4.88 zd30 in daily use that can confirm how this feels and drives like is what im asking for here.

Another thing i want to confirm, - shift points. With 4.88 gears, when does the auto shift to 4th? As for now with the 4.37 gears it shifts from 3rd to 4th at 70 kph. As mostly speed limits are 60 here, i need to break the speed limit to get it into 4th. Going 70, and then i can ease down to 60 where it holds the 4th gear. My hope is that with 4.88's it will change to 4th at around 60-62kph, as would be perfect.

 

 

 

Edited April 22, 20251 yr by KnotGU

On 4/22/2025 at 8:03 PM, KnotGU said:

I read it disingeages at 55 kph

You can modify or use that as an example what is possible. I know  of setup where lockup disengage at whatever you wish or want!

Here ==> https://www.chaz.yellowfoot.org/Lockup Trans Switch.htm

You can hack it any way you see fit. I'd personally go out and mix auto mode with manual overide e.g. have speed related options as well as full manual overide. Alas, mine has manual transmission so I don't need to contemplate it. I've automated some mods on mine and always included manual overide option (boost control, preheat control, fuel lift pump control, intercooler fan control etc.) because why limit yourself.

Standard shifts as per Nissan :

 

Autotrans ratios:

 

Going for 4.88 diffs would increase your rev range and slow you down. Here in Australia those who use 4.88 usually go bigger tyres (33"-35") as well to get back revs/speed

ZD30 loves to drink once you go past its peak torque band of 2000-2500 RPM. Diesels are meant to be driven at peak torque....

This is why I get better fuel consumption around town (10.5 L/100) then on open highway (12.5 L/100) as at 110 km/h mine sits at 2800 RPM. Even at 100km/h it still sits slightly above 2500 RPM so getting down to 2100 would be ideal.

I'd prefer lower ratio for 5th gear e.g 0.70 instead of that factory stupidity 0.80

Regards

Edited April 23, 20251 yr by Rumcajs

So not anyone can tell me the shift points at daily driving with zd30 4.88's? 

Lower gearing will be better for 33's on a top daily speed about 70. Im not interested in answer with 100kph and or manual gears as referance points

On 5/15/2025 at 11:04 PM, KnotGU said:

So not anyone can tell me the shift points at daily driving with zd30 4.88's? 

You will/might have better luck in answering on these Patrols forums:

patrol4x4.com

nissanpatrol.com.au

Very few Nissan Patrol owners in Australia have interest driving at 70 km/h as distances comparing to your local Scandinavian region are on completely different scale. I don't drive my Nissan as daily, and my nearest 4x4 adventure area is 300 km + be it the sand dunes or outback hills are even further 500+ km... No interest in driving at such low speed to get there her ein Oz most people use their Patrols for touring and that means large distances are covered.  ZD30 powered Nissans are not widely customized to run 33' with 4.88 gearing. People who would mod gearing ratios would be those guys with heavily modded TD42 on 35' (highly illegal in Australia) who play in local sand/mud pits or do comps but those models are not auto tranny fitted!

To be honest I'd mod/change the engine first if I indeed wanted to keep Nissan Patrol. Apparently common conversion is to use BMW 3L engine and gearbox combo.....Polish guys like it...

https://www.patrol4x4.com/threads/bmw-m57-into-zd30-patrol.419019/

https://engineswapdepot.com/?p=127470

https://house-of-torque.com/product/6-8hp-to-patrol-y60-61/

 

Edited May 18, 2025May 18 by Rumcajs