[peter.krause06]

Hi i am Peter from Germany.
I have the FD1 CVT and want to ask, if sombody tried to retrifit the Low gear from the FD2 Modell?

 

[Sandstone]

Hi Peter, AFAIK no one has fitted the FDII transmission and rear differential to the FDI.

 

[peter.krause06]

I thought about a smal solution whithout changing the Diff. I think to retrifit just the Elektronik that tells the Variator to stay in smalest Gear Independent of the Engine speed.

 

[Flamewave]

I've been wondering for a while if it'd work or if the computers would throw a fit. If I had the money it'd be an experiment I'd love to try. Would be cool to have the lower gearing but keep the autostick.

 

[Sandstone]

The FDII low gear "off-road crawl ratio" is actually done with lower differential gearing, that's why the FDII doesn't get the MPG the FDI does and the highway RPM's are so much higher.

Years and years ago there was an effort to see if Autostick could be made to work on the FDII.
It looked doable until they found the dealership couldn't enable the autostick function because that function was a "VIN locked" option and not allowed.

But back then these OBDII apps / programs weren't around, so now maybe the factory "VIN lock" is no longer an issue?

 

[mr_et2]

So what all would need to be replaced? CVT and RDU? It LOOKS like Appcar would let you configure it.

Not that I'm interested in actually doing it, just interested to if it's possible.

 

[slivo]

The FDII low gear "off-road crawl ratio" is actually done with lower differential gearing, that's why the FDII doesn't get the MPG the FDI does and the highway RPM's are so much higher.

Years and years ago there was an effort to see if Autostick could be made to work on the FDII.
It looked doable until they found the dealership couldn't enable the autostick function because that function was a "VIN locked" option and not allowed.

But back then these OBDII apps / programs weren't around, so now maybe the factory "VIN lock" is no longer an issue?

View attachment 97034

I have a 2011 Off Road Rated Patriot. Seems to get the same mileage and rpms as a non low range transmission version. Are you sure the differential is different?

 

[peter.krause06]

Yes the Diff is different

 

[Sandstone]

Yes, they're different transmissions as designated by the "L" (low) vs "A" (awd).

Per the Mopar CVT Training Manual:

Mopar CVT Training Manual

Lots of useful info and diagrams for the CVT. CVT Training Guide

www.jeeppatriot.com

 

[Tyler-98-W68]

Patriot. Seems to get the same mileage and rpms as a non low range transmission version. A

Have you actually measured your mileage in closed conditions with a FDII and non FDII vehicle? If not your claim is baseless.

Facts are
FDII models have a completely different transmission
FDII models have a different RDM with drastically different gear ratios.

 

[peter.krause06]

Have you actually measured your mileage in closed conditions with a FDII and non FDII vehicle? If not your claim is baseless.

Facts are
FDII models have a completely different transmission
FDII models have a different RDM with drastically different gear ratios.

The Transmission is the same (Jatco jf011e)
The differenz is just the TCM Software.
Look at Sandstone's post

 

[Sandstone]

Just to clarify, the CVT2A (FDI) transaxle uses a different ring and pinion gear set than the CVT2L (FDII).

 

[Tyler-98-W68]

The Transmission is the same (Jatco jf011e)
The differenz is just the TCM Software.
Look at Sandstone's post

Its not the same transmission, yes it's the "same" but it's not the same due to the different gear ratios, my original post is correct, the difference is not just in the TCM software.

 

[Tyler-98-W68]

FDII vehicles actually have 3 "low" gears as shown below on my 2012 FDII Compass
This is in drive at 30kms/h

In [D]


In [L]


In [L] with 4x4 locked or the FDII Mode


A FDI transmission can't do that at all and no amount of software programming can do that either


I was just thinking about it, FDII vehicles get the 19:1 "crawl" ratio. Turns out my Rubicon 4xe has a 19:1 "crawl" ratio in 1st gear without being in low range.

 

[peter.krause06]

FDII vehicles actually have 3 "low" gears as shown below on my 2012 FDII Compass
This is in drive at 30kms/h

In [D]


In [L]


In [L] with 4x4 locked or the FDII Mode


A FDI transmission can't do that at all and no amount of software programming can do that either


I was just thinking about it, FDII vehicles get the 19:1 "crawl" ratio. Turns out my Rubicon 4xe has a 19:1 "crawl" ratio in 1st gear without being in low range.
[/QUOT

O.k so they have different Ring and Pinion16:1 - FD1 with Auto Stick 19:1 FD2 no Auto Stick but Low Mode with different Ratio in L , 4x4 locked, FD2 Mode.
Do i understand that right?
How do you Switch the FD2 Mode?

At my FD1 i have Auto Stick with 6 simulatet gears. So now i will check out how much rpm i have in first gear and If there is a differenz in 4x4 lock and ESP totaly off.

 

[mr_et2]

How do you Switch the FD2 Mode?

Engage 4x4 Lock and shift the trans into "L - Off-Road"

 

[peter.krause06]

So i checked my FD1 CVT 2 today.
1 Gear Autostik 4x4 locked 3000 Rpm 30km/h. Than ESP Off, no differenz and also with ESP totaly off no differenz.

So there are 500 Rpm differenz to the FD2 Offroad Mode. Now i think i can live with that
and the effort would be too great to change that.