[Gader3]

I only have 600 miles on my Renegade 2.4. I have noticed that the RPMs rev when it is 9th gear and I'm maintaining a constant speed. It even feels like it will choke out when the rev ends. It is only a 100 or 200 RPM difference. I can tell it isn't shifting, just revving. Does anyone else have this problem? And is it normal to only be able to shift to 8th gear with the autostick?

 

[Retiredguns]

when you hear or see it "revving" are you losing or gaining any speed? Can you press the accelerator and get it to shift down? I am not quite sure what you mean about not getting it into 8th gear? If I am cruising on the highway in 9th, a slight press on the gas pedal and she kicks down immediately.

The revving certainly doesn't sound normal. How does it drive otherwise?

 

[Gader3]

It maintains a constant speed; the engine is jumping for lack of a better term. The jeep jerks. This is when I'm on a flat road and driving at a constant speed so there is no reason for a shift attempt.

The autostick (Manual option) only lets me get to 8. Should it go up to 9? I can't find any information to answer that.

 

[Rammer]

With our Trailhawk, 9th gear isn't available to be selected until 63 mph. You don't mention what model you have, but I would think the other models would need even more speed, being they are not geared as low as the Trailhawk.

 

[Retiredguns]

The bucking or jumping is not normal, but you should be able to get the Jeep in 9th gear at the right speed. 9th is pretty tall, but cruising on an effortless road @ 65mph you should be able to put it in 9th. I've had mine in 9th at less than 50mph when conditions require almost zero on the gas pedal.

Does it ever "buck" otherwise?

 

[Gader3]

Nope that is the only time. I tried to schedule a time to bring it in for service and they told me there was a 3 week waiting period. I was at 70 and it wouldn't shift to 9, so I believe I was right that there is something wrong with the transmission.

I have a limited.

 

[bwbike]

You might need to be going faster to use 9th in your Limited since it is geared higher than a Trailhawk. I can't get into 9th until 64 mph even with the Trailhawk's 4.334 final drive. If I'm going up a grade with the air conditioning on, it won't go into 9th by itself (automatic mode).

And I have noticed on the MPG gauge that there times that 8th gear has a slightly better MPG than when in 9th. This is likely due to the engine bordering on lugging if the gear is too high. The 2.4L engine doesn't really make much power until you're over 2,000 RPM.

Try driving at 70+ mph on a flat road or slightly downhill and see if the transmission goes into 9th gear.

 

[raz-0]

Bwbike brings up a good point. Your ~200 rpm Erving is from what rpm to what rpm? At the top end there's likely a rev limiter. At low rpm so it might be upping injector duty cycle to not stall out.

 

[twospirits]

While it may not be Renegade specific, this article about the ZF 9 speed Transmission on the Cherokee (especially paragraphs 4 and 5) is quite interesting in explaining what bwbike is referring to.

TS

 

[Gader3]

Just an update...the problem has steadily gotten worse. There is definitely a transmission problem and I am still waiting to get it fixed. The dealership updated the software, but there was no improvement. Now, I have another appointment and hope it will be fixed for good.

 

[Gader3]

Its been 4 weeks in the shop and a lot of testing to find out there was water in my transmission. It apparently came that way. Now waiting for a new transmission to be put in. Hope this one works.