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I'll do some logging and use some online calculators to figure out if its accurate or not. Everything else in AlfaOBD has been accurate. Its got the proper low range gearing (2.92) now I just need a non tow package vehicle to play around with.
What you are seeing is a semantics issue.
Both are correct, the mfg. and your reader.

The axle ratio and the "final drive ratio" are 2 different things.

Simply said: the gear ratios in the transmission and the gear ratios in the drive axle multiply power to the wheels. The 2 ratios multiplied together give you "the final drive ratio" for the vehicle.
Its all the combination of gears and axle(s) working together to provide power to the wheels for the intended purpose.

The Cherokee is a bit more complex with its drive system.
 

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What you are seeing is a semantics issue.
Both are correct, the mfg. and your reader.

The axle ratio and the "final drive ratio" are 2 different things.

Simply said: the gear ratios in the transmission and the gear ratios in the drive axle multiply power to the wheels. The 2 ratios multiplied together give you "the final drive ratio" for the vehicle.
Its all the combination of gears and axle(s) working together to provide power to the wheels for the intended purpose.
This is true but the two terms are used so interchangeably that they essentially have the same meaning (in usage at least, if not reality.) Even the Jeep build sheet uses the term 'final drive ratio' when they really mean rear axle ratio. Also sometimes a differential is called a final drive, further confusing the issue. Everything gets so jumbled up that in the end 'final drive ratio' most often means axle ratio rather than actual final drive ratio.

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Discussion Starter · #26 ·
What you are seeing is a semantics issue.
Both are correct, the mfg. and your reader.

The axle ratio and the "final drive ratio" are 2 different things.

Simply said: the gear ratios in the transmission and the gear ratios in the drive axle multiply power to the wheels. The 2 ratios multiplied together give you "the final drive ratio" for the vehicle.
Its all the combination of gears and axle(s) working together to provide power to the wheels for the intended purpose.

The Cherokee is a bit more complex with its drive system.
You are preaching to the choir, i'm well aware what the ratios are 0:)

I wouldn't be surprised if jeep is wrong again. They describe their AWD system operation as wrong and I've proved that before.

Again I'm very well aware what my build sheet says on my cherokees, doesn't mean it is 100% accurate
 

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This may sound amateuristic (and sorry if so), but can someone confirm that the difference be the V6 non-tow package 3.251 final drive ratio and factory tow package 3.517 ratio is actually different hardware (e.g. gears), when built at the factory?

I noticed in AlfaOBD there's an option to set the Final Drive Ratio. Of course, that doesn't make it automagically change the ratio if it's reliant on specific hardware but can anyone confirm this is not just a software-controlled shift or gear point? Please no guesses (e.g. "I think", "I heard" etc.) - anyone with direct 1st-hand knowledge that can confirm?
Font Rectangle Screenshot Technology Number
Font Parallel Screenshot Number Document
 

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All KL Cherokees use the same 948TE transmission which alone is a front wheel drive transaxle, and 4WD vehicles add a PTO (power take off) module to supply power to the rear wheels. This is the module where the gearing may vary. Different PTO gearing uses physically different gears and the setting you are seeing is to allow proper programming if the PTO module is ever changed from the factory configuration.

Or at least I think I heard that.

 

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You know, it's a damn shame that he went and got himself banned, because he contributed a great deal here.
 

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This may sound amateuristic (and sorry if so), but can someone confirm that the difference be the V6 non-tow package 3.251 final drive ratio and factory tow package 3.517 ratio is actually different hardware (e.g. gears), when built at the factory?

I noticed in AlfaOBD there's an option to set the Final Drive Ratio. Of course, that doesn't make it automagically change the ratio if it's reliant on specific hardware but can anyone confirm this is not just a software-controlled shift or gear point? Please no guesses (e.g. "I think", "I heard" etc.) - anyone with direct 1st-hand knowledge that can confirm? View attachment 220772 View attachment 220773
i have good scan tool and tow package 3.6 2017, want me to snoop
 

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i have good scan tool and tow package 3.6 2017, want me to snoop
Thanks AuroraGirl. According to the documentation in nocaps link above, there's actual different physical gearing which would explain why this is a factory build-only option. Even if the dealer adds a Mopar hitch/bumper assembly and wiring after it's been delivered, the gearing in the power transfer unit will still be the non-tow ratio. Thanks! (you got lucky and got yours with the tow package!)
 

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Thanks AuroraGirl. According to the documentation in nocaps link above, there's actual different physical gearing which would explain why this is a factory build-only option. Even if the dealer adds a Mopar hitch/bumper assembly and wiring after it's been delivered, the gearing in the power transfer unit will still be the non-tow ratio. Thanks! (you got lucky and got yours with the tow package!)
If it showed up on the window sticker it was OE, right? I have to find where I put the sticker but Im 99% sure its had it on the lot and one of my gmas primary reasons for going that option was the fact it had a trans cooler, which my gpa had made as one of the "would be smart" things to her purchase. The car has the wrong tire size on it tho so I technically have not experienced it with the right tire size since the oem tires were replaced early because winter came up and they were well used in the first few months. WOnder if it would make the shift hanging not as bad.
 
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