6-Speed 4.10s with 37s Need Some Help

[DreamedofaJeepSomeday]

If you shift by speedo, then you should not be driving a manual

Not. Depends on conditions. Where I mostly drive everything is flat, flat. You can shift by tach, speedometer, engine noise, acceleration, combination of one or more.

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[tjbrown23]

3000 rpm is when the computer increases the oil pressure for high rpm running. You can see it on your own gladiator if you turn on the oil pressure gauge. Mechanically, the objective is to stay under this 3000 rpm threshold for long hwy driving in your highest gear - 6th for the manual. I believe with both 4:88s or 5:13s you will always be under 3K rpm on the fwy in 6th..., so, .... probably best to go by your needs - flat terrain... or mountains and towing.

Thanks for that info, I will take a look next time I take it for a spin, but it sounds like 4.88s are the way to go for me. I don't mind downshifting for some power. Based on some of the calculations and research I've done the 4.88s will put me a few hundred rpms above where stock would be, 5.13s would probably be too much and I won't be going any bigger than 37s.

 

[tjbrown23]

Not. Depends on conditions. Where I mostly drive everything is flat, flat. You can shift by tach, speedometer, engine noise, acceleration, combination of one or more.

That makes sense if all external conditions are equal all the time but in most of the country that's just not possible, especially in WV everything is up or downhill lol

 

[Hardhead]

Not. Depends on conditions. Where I mostly drive everything is flat, flat. You can shift by tach, speedometer, engine noise, acceleration, combination of one or more.

Flat here I drive and dont even use the clutch once i get moving. Could care less about tach or speedo. But I drive a 10 speed for a living

 

[DreamedofaJeepSomeday]

3000 rpm is when the computer increases the oil pressure for high rpm running. You can see it on your own gladiator if you turn on the oil pressure gauge.

I did, and that was a neat suggestion. Mine went from 30 psi to 80.

 

[tjbrown23]

So I did get my speedometer calibrated using the AEV procal snap which worked pretty good but installing the wiring harness was a pain. I just didn't want to risk using a tazer and screwing things up and voiding my warranty. AEV does a lot of work for jeep and even does some of the parts in production.

With the 6 speed manual it only changed the displayed speed everything else was the same. I was able to get it spot on and able to drive a few hours. Highway driving actually was pretty good now that I knew my exact speed.

At 55 4th is perfect about 2300rmp and enough power to keep a steady speed even cruising at 60. 5th is 1700 to 1800rmp and couldn't keep a steady speed without lugging it around at 55-60mph. (Keep in mind this is with mild WV hills)

I have yet to hit the interstate but my guess is 4th up hills and 5th for flat/downhill. With 37s and 4.10 gears I can almost guarantee 6th is useless. On the stock 33s 6th was almost useless especially with it being very close to 5th. I have a feeling I will not be regearing as this setup seems perfect for me. Practically a 4 speed with 5th as an overdrive.

 

[DreamedofaJeepSomeday]

3000 rpm is when the computer increases the oil pressure for high rpm running.

So does this mean:

1) the oil pump is electric?

2) the computer just controls a pressure-regulating valve? (i.e. the pump always produces the higher pressure)

3) something else I have not thought of?

 

[basicGlad]

Shift points in A manual transmission are software driven

I think I vaguely remember hearing the Gladiator has "anti stall technology". I find my manual very hard to lugg the engine even if I try. I think the computer won't let your RPMs drop so low they stall.

 

[seven30]

I think I vaguely remember hearing the Gladiator has "anti stall technology". I find my manual very hard to lugg the engine even if I try. I think the computer won't let your RPMs drop so low they stall.

Ha, they must have forgot that on my 6mt. 4.88 with 37s sure seems perfect to me. Makes 6th a tad lower than stock with 4.10.

 

[hjdca]

Ha, they must have forgot that on my 6mt. 4.88 with 37s sure seems perfect to me. Makes 6th a tad lower than stock with 4.10.

4:88s or 5:13s with 37 inch tires -- both are great.

If you run the air conditioning a lot, or live in a hilly or mountainous area, or do any towing, or want to be faster in the 1/4 mile than people with 4:88s, then, the 5:13s are better. Get up and go is great with the 5:13s.

PS. I think the stock Rubicon with 33s should have been 4:56 instead of 4:10.

 

[seven30]

4:88s or 5:13s with 37 inch tires -- both are great.

If you run the air conditioning a lot, or live in a hilly or mountainous area, or do any towing, or want to be faster in the 1/4 mile than people with 4:88s, then, the 5:13s are better. Get up and go is great with the 5:13s.

PS. I think the stock Rubicon with 33s should have been 4:56 instead of 4:10.

I suspect you are right about the 4:56 gears. I got the Mojave just so I could have 4:10 with 6mt. But even that combo is a bit tall in 6th. At 8k altitude 6th was pretty useless.

 

[jc1986]

So, would 4.56 or 4.88 be ideal for rolling hills and occasional trail time with 35s? I know aev re-gears to 4.56 on their builds.
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[Deleted member 39643]

I don’t remember ever shifting by anything but engine noise, except for when I was first learning to drive a stick.

Our gladiator is super quiet to accomodate the auto crowd so driving by engine noise takes a lot of concentration. Might need to get cutouts as well as regear, or just chop that exhaust ang get a student driver sticker ha ha jk

Here is a gear calc that will show you the exact speeds / RPMS for any given regear / tire combo. I'd study this to make sure you like it.
gear calculator http://www.grimmjeeper.com/gears.html

Also, the gearing the Gladiator isn't spaced consistently, so you will have to make sacrafices somewhere, either at the top or bottom of the gear range. I'm considering 5.13 gears on stock 31.5 in tires. Hoping to have 1st as dedicated crawl gear and start in 2nd / cruise in 6th.

 

[syreeves]

Here is what I shift at based on engine power and available acceleration potential. I am a 6MT JTR with stock 4.10 riding on 35s. But all of that doesn't really matter because I think the original question is about available engine power.

1st - min 3000, preferably at 3500 but no higher than 4000 (for longevity- unless I am really beating on it)- this means a drop to about 2300 in 2nd but for me 2nd has enough power in most situations to keep accelerating even in the 1500-2300 range.
2nd - min 3000, preferably at 3500-4500 (especially when going up hill or pulling a trailer). The drop to 3rd is about 1500rpm so you can lug if you don't shift high enough. Also - when accelerating hard learn to wait have a sec before dropping the clutch on 3rd because the flywheel keeps the engine spinning - if you shift too fast you are just burning up your clutch. You need to let the engine drop to the right speed
3rd - min 2800 but preferably about 3000 - will drop to 2200. in the 3.6 there is no real engine power in higher gears below 2300. Hate to say this but for me at 3000 in 3rd I'm now driving about 45mph.

4th - about 2800 - which is about 55mph - will drop to 2300.

5th - about 2500 - which is about 64pmh - 5th to 6th is about 500rpm drop. For me anything below 2300 in 6th = no power and increased gas mileage. I am better of in 5th for 60-70 and 4th for 55-65 if towing) on mileage and acceleration.

 

[SteveInOrlando]

I think I vaguely remember hearing the Gladiator has "anti stall technology". I find my manual very hard to lugg the engine even if I try. I think the computer won't let your RPMs drop so low they stall.

Yeah, no!

very easy to stall this thing by dropping the RPM too low. If RPM get down to 500RPM, this thing falls on its face.

There is a nice video out there demonstrating the difference between a weighted flywheel and the stock flywheel idling up a hill. The stock flywheel stalls out halfway up the hill.

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