3.6 6MT Engine braking on Wrangler

[AlgUSF]

I've always used the engine to brake on manuals when driving relatively aggressively. I noticed in the owners manual it says that the maximum recommended downshift speed from 3 to 2 is 30 MPH. That seems super low, given that you are only going about 3K at 30MPH. I wouldn't think engine braking on 2 at 45-50MPH would be that bad. You certainly aren't redlining the engine at that speed, is there something that I'm missing? Does it have something to do with the heavier clutch setup, or is this CYA on chrysler's part? I've done this type of driving on many types of vehicles and they've lasted a long time (one over 265K). Maybe someone who knows the engine/clutch setup better than I can answer this.

I know that it can't be bad for the transmission itself because in a synchromesh all gears are spinning no matter what what gear is selected. If the synchro hasn't spun up before the shift, it certainly reminds you of that fact.

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[AMKRubicon610]

I've always used the engine to brake on manuals when driving relatively aggressively. I noticed in the owners manual it says that the maximum recommended downshift speed from 3 to 2 is 30 MPH. That seems super low, given that you are only going about 3K at 30MPH. I wouldn't think engine braking on 2 at 45-50MPH would be that bad. You certainly aren't redlining the engine at that speed, is there something that I'm missing? Does it have something to do with the heavier clutch setup, or is this CYA on chrysler's part? I've done this type of driving on many types of vehicles and they've lasted a long time (one over 265K). Maybe someone who knows the engine/clutch setup better than I can answer this.

I know that it can't be bad for the transmission itself because in a synchromesh all gears are spinning no matter what what gear is selected. If the synchro hasn't spun up before the shift, it certainly reminds you of that fact.

I did not know this! I do this as well. I try to rev match when I do it but not sure if that helps or hurts it

 

[AlgUSF]

I did not know this! I do this as well. I try to rev match when I do it but not sure if that helps or hurts it

Yeah, you'd think that if something was "bad" there would be some sort of adverse indication. I had a Chevy Cruze 6MT fun little car to drive, but you couldn't run out first gear otherwise when you went down to second, it would grind because the synchro didn't catch up. Took some of the fun out of driving it around Tampa.

The Jeep seems to handle fast shifts brilliant. High revs, low revs, just don't lug it, 3.6 wranglers don't like to be under 2k.

 

[JLRyder]

I get an audible and visual alert when I downshift into second over 30. Only does it once though. No issues so far...does seem a little low.?

 

[AMKRubicon610]

I get an audible and visual alert when I downshift into second over 30. Only does it once though. No issues so far...does seem a little low.?

This isn’t the first I’ve heard this, however mines never done this for me. I received my wrangler after the clutch recall flash back in March

 

[Rodeoflyer]

I use engine braking in the mountains and foothills around here but never really on flatter terrain. The gears are so far apart it's difficult to drive it like a car with closer ratios. It's more of a truck transmission and drives as such. It kind of fools you being as smooth as it is lol. I'd love to have another gear between 1st and 2nd or 2nd and 3rd instead of 2 overdrives.. but it is what it is and that's what we got.

Gear Ratios:

• 1st - 5.13
• 2nd - 2.63
• 3rd - 1.53
• 4th - 1.00
• 5th - 0.81
• 6th - 0.72
• Reverse - 4.49
• Final Drive ratio - 3.45 standard, 3.73 optional (4.10 Rubicon)

 

[jonahgetz]

I'm worried I may be lugging the motor too often because I'm trying to stay under 2k RPMS and increase fuel economy. I've heard from Rubicon owners that the 4.10 gear ration makes the manual feel a totally different way. Some say it feels "right". In my Sport, I sometimes struggle to figure out what gear to use while cruising on the freeway. If I'm going 75 and go into 5th, I'll feel like I lose speed on slight hills and I start to lug the engine so I have to downshift. I still have no idea when to use 6th gear, it feels like its useless for Sport gear ratio?

I've read the Jeep manual and they mention the proper gear changes according to speed, but the higher gears and speeds still don't feel right. It claims 65 mph under acceleration is 4th to 5th gear change, followed by 70 pm under acceleration is 5th to 6th gear, but this feels like such a high gear and it seems like the engine immediately lugs due to losing torque and being under 2k RPMs.

I think its great to get this thread going because I know many of us manual drivers have different findings on the JL. We're all learning together.

 

[Rodeoflyer]

That's because at 75mph your jeep is pushing so much air with it's terrible aero lol. 6th is pretty much useless, even with the rubicon 4.10s. With 35'' tires I have to be doing 80mph to use 6th. I'd prob get it back with some 4.88-5.13 gears but that's down the road at least until the factory warranty has expired. I'd much rather have another gear between 1/2, 3/4 or 4/5 for a vehicle like a jeep.

The JK had better 3rd and 4th gear ratios....
Gear Ratios
1st.... 4.46
2nd.... 2.61
3rd.... 1.72
4th.... 1.25
5th.... 1.00
6th.... 0.84
Reverse.... 4.06
Axle Ratio....3.21 Std., 4.10 Opt. (Std. on Rubicon)

 

[OldGuyNewJeep]

I've heard from Rubicon owners that the 4.10 gear ration makes the manual feel a totally different way. Some say it feels "right".

Can confirm. I’m satisfied with how my Rubicon is geared with stock 33” tires. I rarely use 6th unless it’s flat and I’m going 75+, but it does drop RPMs a smidge at that speed.

I never hit more than 4000 RPM in 2H normal street driving. Maybe 4500 if my hair were on fire. I usually shift Around 3000.

I would never downshift to 2nd at more than 30. It’s a Wrangler, not a Miata. I do employ engine braking and rev match to make that a smooth affair, but when I need to quickly decelerate I use the brakes. My $0.02.

 

[AlgUSF]

This isn’t the first I’ve heard this, however mines never done this for me. I received my wrangler after the clutch recall flash back in March

I've heard of these warnings too, but my Wrangler doesn't give any audible or visual alert. I've also heard of speed relative lockouts for first and second, but I've never had first or second locked out either in my wrangler. Could it be that the recall "fix" has eliminated the need for these warnings of overspeeding the clutch. I think it is a far fetched assumption unless the cluch/pressure plate designs are different on newer Jeeps.

I don't usually go flying around a corner engine braking my Wrangler. Sometimes when I'm coming off the freeway and the left turn light has been green for a while, I like to bleed off speed a little faster going around the corner and to be in the correct gear. I feel that I have more control using the engine to brake in situations like that.

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