Jatco & Aisin transmissions

[Ian Sharpe]

Was reading a review of the NT diesel when it was first released with the Aisin tranny. Blurb said the NT was now “punchier” due to the first gear of the new tranny.
Looking at the specs on both trannys , the Jatco first gear is 3.8 & the Aisin is 3.52 so it would appear to me that the Jatco would be more “punchier” because it has a lower ratio.
Unless of course the extra punch wasn’t coming from the tranny but in fact from the “punchier” 3.2 tdi with 18% more torque!

[old Jack]

Hi Ian,

My reading has the;

NS 3.2 with the Jatco auto as 118kW, 392Nm@2750rpm, 1st gear ratio of 3.789:1, Torque Convertor stall ratio 1.62 and diff ratios of 4.1:1.

NT 3.2 with the Aisin Auto as 147kW (25% more), 441Nm@2000rpm (12.5% more), 1st gear ratio of 3.520:1 (7% higher) Torque Convertor stall ratio of 1.85:1 (14% more slip) and diff ratios of 3.917 (4.5% higher). So even though the 1st gear and diff ratios are higher, the extra power and torque of the engine combined with the extra torque multiplication effect of the higher stall ratio TC will give more off the line performance.

OJ.

[pharb]

Was reading a review of the NT diesel when it was first released with the Aisin tranny. Blurb said the NT was now “punchier” due to the first gear of the new tranny.
Looking at the specs on both trannys , the Jatco first gear is 3.8 & the Aisin is 3.52 so it would appear to me that the Jatco would be more “punchier” because it has a lower ratio.
Unless of course the extra punch wasn’t coming from the tranny but in fact from the “punchier” 3.2 tdi with 18% more torque!

Normal modern day media who have no idea what they are actually working with

I remember reading motoring magazines as a kid where the author would go to great lengths to explain the mechanics of what made the vehicle feel the way it did. Even power and torque graphs and calculated over all gearing to explain why one vehicle felt different to drive in particular circumstances to another.

Now they all seem to just talk about how this new model feels better than the old. But not really why.

Rarely find an article that doesn't just seem like an infomercial.

Still have to chuckle when I still see an "road test" every now and again that shitcans the placement of the Pajero air intake due to possibility of water intake on water crossings, as though they have just discovered this flaw even though it has been there for 20 years, without any published ill affects.

[nj swb]

I began to take published road test reports with a grain of salt when the Magna was released. One major magazine praised its neutral handling, the other criticised it for terrible understeer.

[Ian Sharpe]

Hi Ian,

My reading has the;

NS 3.2 with the Jatco auto as 118kW, 392Nm@2750rpm, 1st gear ratio of 3.789:1, Torque Convertor stall ratio 1.62 and diff ratios of 4.1:1.

NT 3.2 with the Aisin Auto as 147kW (25% more), 441Nm@2000rpm (12.5% more), 1st gear ratio of 3.520:1 (7% higher) Torque Convertor stall ratio of 1.85:1 (14% more slip) and diff ratios of 3.917 (4.5% higher). So even though the 1st gear and diff ratios are higher, the extra power and torque of the engine combined with the extra torque multiplication effect of the higher stall ratio TC will give more off the line performance.

OJ.

Yeah
So as I suspected it has nothing to Do with the transmission first gear ratios at all

[ironrock]

Sorry if this topic has been already discussed has anyone upgraded from a jatco to an aisin , what wud be the steps , am guessing there will be ecu changes etc too

[Perri]

Sorry if this topic has been already discussed has anyone upgraded from a jatco to an aisin , what wud be the steps , am guessing there will be ecu changes etc too

https://www.pajeroforum.com.au/forum/vehicles/generation-4-1-pajero/1069416-installing-aisan-nt-gearbox-on-a-ns-pajero-iwth-jatco