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Discussion Starter · #1 ·
It seems like my Renegade does not go into 9th gear unless I back off a little on the gas at about 70-75 miles per hour. Then it slides into 9th gear, the RPM drop off to about 1600. Does this sound normal? You would think that it would shift into 9th gear without having to back off on the gas. Otherwise the Jeep shifts perfectly
 

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It seems like my Renegade does not go into 9th gear unless I back off a little on the gas at about 70-75 miles per hour. Then it slides into 9th gear, the RPM drop off to about 1600. Does this sound normal? You would think that it would shift into 9th gear without having to back off on the gas. Otherwise the Jeep shifts perfectly
I bet someone will reply with all the specifics on the transmission shift points, but what you describe is normal. You wouldn't want the engine running lower than 1600 RPM.
 

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I bet someone will reply with all the specifics on the transmission shift points, but what you describe is normal. You wouldn't want the engine running lower than 1600 RPM.
This is true. For most of us getting into 9th gear is not going to happen very often. If fact since our car is driven mostly in the city I don't think we will ever get there.
 

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It seems like my Renegade does not go into 9th gear unless I back off a little on the gas at about 70-75 miles per hour. Then it slides into 9th gear, the RPM drop off to about 1600. Does this sound normal? You would think that it would shift into 9th gear without having to back off on the gas. Otherwise the Jeep shifts perfectly
What's your build date? That was exactly the behavior I was seeing before I got the tpm flashed.

For the other posters, it's hitting ~1600 after the shift to 9th. Which is the target efficient rpm for the vehicle it seems. It's holding gear when it could shift.
 

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Our Renegade hit 9th gear quite a bit on a recent 2406 mile round trip. It is mostly after 65mph on very flat roads. Any incline, wind, etc.. and back to 8th in a heartbeat. Can't expect the Jeep to stay in 9th @1600rpm except under perfect conditions. We averaged 31mpg on that trip and one stretch of 256 miles @ 32.5mpg. Love it.
 

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Our Renegade hit 9th gear quite a bit on a recent 2406 mile round trip. It is mostly after 65mph on very flat roads. Any incline, wind, etc.. and back to 8th in a heartbeat. Can't expect the Jeep to stay in 9th @1600rpm except under perfect conditions. We averaged 31mpg on that trip and one stretch of 256 miles @ 32.5mpg. Love it.

That is quite a trip. I have not driven that far in many years.
 

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My Trailhawk will never shift into 9th gear unless I am going faster than 63 mph. Once in 9th, if I move the lever to manual mode, it will stay in 9th all the way down to 50 mph if I let it. Obviously 50+ mph is way out of its power band and will take forever to accelerate until the rpm gets to at least 2,000.

The two highways near me have speed limits of 65 and 55 mph. At 65 mph, it will shift to 9th unless there is a grade or a stiff headwind. At 55 mph, the highest it will go is 8th. But even in 8th at 55 mph on level roads, I can easily exceed 30 mpg. Not bad for a boxy shaped car.

Those with cars other than the Trailhawk may experience shifting differently than I since the final gear ratio is different.
 

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Discussion Starter · #8 ·
My build date is May 2015. As I stated, you would think it would enter 9th gear at a certain speed and stay in 9th gear until you accelerate, then logically downshift into a lower gear. Mine only enters 9th gear if you back off the accelerator a bit then hold the throttle steady. Like I mentioned earlier, it otherwise shifts perfectly
 

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joejamiejeep,

What model do you have? My build date is January, 2015.
 

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Mine seemed to rarely go into 9th and almost always drop back down to 8th as soon as it got into 9th, especially going up the slightest incline. I have about 3500 miles now and it stays in 9th even going up and down slight hills. Same interstates. Maybe the thing finally "learned how to shift"? I was really upset about this thing initially, but it seems to have worked its issues out on its own? Mine had about 130 test drive miles on it, maybe that has something to do with it's "learning curve"? Anyway I feel confident in it enough to put the Factory/RR hitch on it this weekend.
 

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I have played with the shifting a lot.I manually can not get it to go into 9th gear until 72 MPH. It will go in in auto mode but as other people said not until around 75 and leaving off the gas. Would be nice if it was a little lower considering most states on the east coast max speed is only 70 MPH...I normally run it up to 75 MPH get it into 9th put it in manual mode then slow back down to 70 MPH and been able to average about 30 MPG.
 

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Remember that the non-Trailhawk automatic cars have a higher final drive ratio. Thus shifting into 8th & 9th gears will happen at a higher speed than it does in a Trailhawk.
 
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I really think the only reasons for 9 gears is so they could use the same transmission for both the Trailhawk and non-Trailhawks. Due to the final drive ratios it sounds like Trailhawks will not go into first unless they are in 4WD low and non-Trailhawks will not go into 9th unless going over 80 or under no load.

Our 6th gear is the same way. Even at 80 mph you can't accelerate in 6th. It's really only to eliminate compression braking while under fuel cut. I have a feeling your 9th is the same. If the injectors have to fire it drops it back to 7th or 8th. That's why you can get it to go into 9th by letting off the gas; the ecu knows you're only rolling and wants to get the most distance before it kicks the injectors back on.

Just my theory at least,

-Jason
 
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Mine wont even go into 8th...much less 9th. Currently sitting at the dealer after Chrysler said its normal for it to not go into 8th automatically....

Complete and total lie. Possibly not malicious though. They may be extrapolating from the cherokee, and as configured, that model tends to use the top gears much less than the renegade does.
 

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I really think the only reasons for 9 gears is so they could use the same transmission for both the Trailhawk and non-Trailhawks. Due to the final drive ratios it sounds like Trailhawks will not go into first unless they are in 4WD low and non-Trailhawks will not go into 9th unless going over 80 or under no load.

Our 6th gear is the same way. Even at 80 mph you can't accelerate in 6th. It's really only to eliminate compression braking while under fuel cut. I have a feeling your 9th is the same. If the injectors have to fire it drops it back to 7th or 8th. That's why you can get it to go into 9th by letting off the gas; the ecu knows you're only rolling and wants to get the most distance before it kicks the injectors back on.

Just my theory at least,

-Jason

You are both wrong and right I suspect. They use the 9 speed in both and in other cars for the same reason: fuel economy. 9 gears lets you have a wider spread of gear ratios than a CVT would get you without running into durability and packaging problems.

I think your logic on how 9th is used is closer to being right. However I can say that with the TH you get into 9th with the injectors feeding fuel, not jsut coasting. If engine load goes to any significant value, it shifts down to 9th. At least based on the data logging I have done.
 

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Driving with cruise control on a flat road today at 55 mph, I felt a gear change I checked and it was in 9th. I feel this gearbox may suit diesels better. The engine was I think at about 1300 rpm.
 

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I have had my Latitude shift into 9th as slow as 63 mph. I also live at 5000ft altitude. It will shift into 9th under (light) load, but only under light load. If I take my foot of the gas or back off, it will stay in 8th.
 

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I'd imagine 9th's lofty gear ratio would have the engine spinning incredibly slow. Most engines use a mass airflow sensor, vacuum sensor, or both to determine engine load. It's obvious that one wouldn't want to be in a gear too tall from a power perspective, but what might not be so obvious is that if the load on the engine is too high, it can be more economical to run at a higher rpm under less load, too. So let's figure out just how slowly these engines are spinning.

First, we need to determine how far your tire travels in one revolution.
Let's use the same tire size for everything to make life easier as the overall radius will all be about the same.
215/60R-17
Tire Width: 215 mm
Aspect ratio: The tire sidewall is 60% of the tire’s width --> (215mm)(0.60) = 129 mm --> 5.08 inches
Wheel Size: 17 inches
Tire & Wheel Radius: 5.08 in + 0.5(17 in) = 13.58 in
Circumference of Wheel = 2πr = 2π(13.58 in) = 85.33 in.
This means for every rotation of the tire it travels 85.33 inches.

Let’s compare all of the Renegades – automatic non-TH, automatic TH, and manuals, respectively – at 70 miles per hour. First, converting 85.33 inches to miles is 0.001347 miles.



So we can see that at 70 miles per hour, Trailhawks would be spinning at 1800 rpm in 9th, a far more probable engine speed/load for the transmission's computer to decide to go into that gear compared to non-TH automatics at 1550 rpm.

As mentioned earlier, the "Low Range" isn't a traditional, secondary gear reduction as you'd find in traditional 4x4's with longitudinally mounted engines. The Trailhawk simply has a shorter (numerically larger) final drive ratio and starts off most of the time in second gear; low range is simply first gear. The taller (numerically shorter) final drive in non-trailhawk automatics reduces the torque reduction in all gears making first-gear starts the norm, but makes 9th so lofty it can seldom be engaged. So sure, 1st can be engaged when in low range for TH and non-TH owners can get into 9th probably around +80 mph, but this transmission becomes an effective 8-speed automatic for normal, real-world driving.

Though Trailhawk's don't have a traditional low-range, this is honestly kind of clever but you can really only get away with that in something like a 9-speed automatic. Could you imagine if we still lived in a world of 4-speed automatics and all of you automatic owners would have a realworld 3-speed?
 

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