6MT 3rd Gear Power Interruption

[Regular Guy]

Digging up and old threading my first post.

I have a 24 JL 3.6 and mine began doing the same thing at 500 miles. So far I've noticed the skip in second and third, and under 2000 RPM with steady throttle. The odd thing I notice is that it's only happening a few seconds after a gear change, and I cannot seem to product on command.

The engine also developed a rough idle around the same time.

Has anyone determined a cure for this?

Mike

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[JTDay]

37,000 miles on my 22 now and it almost never happens anymore. Naturally, as I learned the 3.6 powerband, I started getting deeper into the RPMs in 2nd gear before shifting to 3rd. It just works better.

Whatever it is, it's something programmed by Jeep: fueling, throttle plate position, cam timing, who knows. Whatever the programming, it results in the little jerk phenomenon before 2000 and around 2700 in 2nd and sometimes 3rd. Naturally, I just started shifting closer to and beyond 3000rpm in 2nd and that alleviates the issue for me. The only reason I was "short-shifting" to begin with is that I've always sort of shifted between gears based on "sounds and vibrations" of which the Jeep has a LOT. So in my head, there was enough sound and vibes to shift up but it really too early. Now I just accept that these engines in a Jeep with little to zero sound insulation sound pretty awful but it doesn't mean the engine is going to blow up at 3500rpm, it's just noisy.

 

[ArchEtech]

I have not noticed anything like that in my six speed Rubicon. I do think that the gearing versus power curve is kind of quirky and so it takes getting used to, knowing when to shift and where the power is.

I think between 3000-4500 it has some nice get up and go without being too high in the rpm band. It definitely takes getting used to.

I don’t remember if it was on this forum or not, but somebody had made the comment that the six speed is more like a four-speed with a couple of overdrives and I would agree with that. You don’t really have to even use 5th gear and certain never have to use 6th.

You pretty much stay in 4th for almost all of your driving even at highway speeds if you really want to. Honestly, honestly, I don’t know a whole Lotta difference between fifth and six gear on the RPMs maybe 500? When you get to 70 or so 5th quiets things down but I barely notice anything different in 6th gear than just staying in 5th.

First gear needs to get pretty high RPM to get any power then it kicks in like a slow spool turbos. With the 4:10 it’s grabby.

Second gear about the same, but seems to make torque a lot earlier.

Third gear to me seems like it’s geared the best and makes power when you’re expecting it too but fortunately I haven’t noticed any kind of dip. It seems to be my favorite accelerating gear around and stay in it around town. 45-50 then I’ll use 4th. Still getting used to it and experimenting.

The interesting thing for me is I test drove an automatic and manual back to back a couple of times before my purchase last week and after all the raving reviews about how the 8speed uses the curve so much better I thought the automatic felt like an absolute slug, and you had to floor the thing to get any power out of it. Maybe that’s just because it’s smooth and it is.
And the transmissions are really good. I’ve had them in some past really nice cars like an RS7.

Because I had already had set my mind on getting a manual I had bias, but it just feels better with a six speed and I like having the control. Could be anecdotal. I don’t know? I thought that I read that the best is 0-60 times in our Jeep Gladiators had been performed with the six speed manual though in lightest sport trims, so maybe I’m right after all?

 

[Regular Guy]

I have been shifting at or around 2000 RPM which drops by 3-500 RMP by the time the gear is engaged. With the advise of the last two posts I tried shifting at 2700-3000 and it's not producing the hesitation, and defiantly less engine braking when engaging the clutch.

I guess the programming is forcing the higher RPM shift points even if it feels unnecessary. It's been a while since I drove manual as a daily. This newer technology is comparably a whole new thing than the days of driving a V-8 where you could lug it at 400 RPM and shift at 1200, or when I had a Mazda 4 cylinder, and never see 3000 are gone. These newer engines love to wind out.

Now I just need to fix the rough idle.

I appreciate the comments!

Mike

 

[ArchEtech]

^^^^ it likes to be shifted higher in the RPM and it takes getting used to. Since it doesn’t make power until pretty high in the bad you don’t have to worry about it getting away from you like you do on a really torqy hellcat or something when you shift high in the band.

I will say you can chirp 1st 2nd and 3rd gear if you get on it……so it’s definitely not a dog..

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