4wd Lo is Jerky Jerky

[flick2614]

No matter how much I finesse the throttle my Rubicon Diesel is really rough driving in 4lo. Going up hills with steady throttle is about the only time it is tolerable, on flat sections it'll give you whiplash. I end up just doing everything in 4hi because it is so rough, I even shifted all the way to 5th gear to try to smooth it out.

Anyone else struggling with this?

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[BDinTX]

Are you still on stock tires? If you are I could see how it would seem terribly low geared in 4lo.

 

[flick2614]

Are you still on stock tires? If you are I could see how it would seem terribly low geared in 4lo.

37" Nittos, 3.5" Metalcloak game changer. Pretty sure the Jeep is regeared but I'm not sure of the ratio.

 

[BDinTX]

hmm... does it feel like slop in the drivetrain?

 

[grimmjeeper]

37" Nittos, 3.5" Metalcloak game changer. Pretty sure the Jeep is regeared but I'm not sure of the ratio.

What RPMs do you turn at 75 on the highway in 8th gear?

 

[flick2614]

hmm... does it feel like slop in the drivetrain?

There was an issue with the transfer case engagement; it popped out of 4hi, I adjusted the linkage, it popped out of 4lo, so I adjusted the linkage again. The little dog ear used to adjust is a horrible design in my opinion. But I'm fairly certain the engagement is solid as in the uphill example feels solid.

 

[flick2614]

What RPMs do you turn at 75 on the highway in 8th gear?

I'll have to pay attention to get an exact number next time I drive but I believe it's typically around 2000.

 

[grimmjeeper]

I'll have to pay attention to get an exact number next time I drive but I believe it's typically around 2000.

Sounds like you may have 4.56s.

 

[C.Sco]

I'll have to pay attention to get an exact number next time I drive but I believe it's typically around 2000.

That sounds like it's not regeared to me, but I'm not 100% sure. I also have the same 37" Nittos on my JLUR, am not regeared (factory 4.10), and I think that's about what my RPM is at 75 mph too. I'm pretty sure your RPMs would be higher than that if you had 4.56+ gearing.

It would be weird for someone to put 4.56 gearing in a Rubicon... because regearing is expensive and so usually people would do at least 4.88's just to make sure they never have to regear it again in the future. Going from 4.10's to 4.56's would be a really expensive upgrade for not a lot of difference, and if they were regearing for 37" tires then 4.56 would be an odd choice anyways.

 

[flick2614]

That sounds like it's not regeared to me, but I'm not 100% sure. I also have the same 37" Nittos on my JLUR, am not regeared (factory 4.10), and I think that's about what my RPM is at 75 mph too. I'm pretty sure your RPMs would be higher than that if you had 4.56+ gearing.

It would be weird for someone to put 4.56 gearing in a Rubicon... because regearing is expensive and so usually people would do at least 4.88's just to make sure they never have to regear it again in the future. Going from 4.10's to 4.56's would be a really expensive upgrade for not a lot of difference, and if they were regearing for 37" tires then 4.56 would be an odd choice anyways.

I bought this Jeep with the lift and tires as well as some other parts. There are a lot of confusing mods on it, some cheap, some expensive for no reason so it wouldn't surprise me. I just need to get the back end in the air and confirm gears.

 

[grimmjeeper]

That sounds like it's not regeared to me, but I'm not 100% sure. I also have the same 37" Nittos on my JLUR, am not regeared (factory 4.10), and I think that's about what my RPM is at 75 mph too. I'm pretty sure your RPMs would be higher than that if you had 4.56+ gearing.

It would be weird for someone to put 4.56 gearing in a Rubicon... because regearing is expensive and so usually people would do at least 4.88's just to make sure they never have to regear it again in the future. Going from 4.10's to 4.56's would be a really expensive upgrade for not a lot of difference, and if they were regearing for 37" tires then 4.56 would be an odd choice anyways.

All factory equipped diesels came with 3.73 gears. Even the Rubicons.

I haven't regeared and on 37s I'm well below 2,000 RPM at 75 in 8th gear.

 

[cnapierala]

37" Nittos, 3.5" Metalcloak game changer. Pretty sure the Jeep is regeared but I'm not sure of the ratio.

Here is how to figure out your gear ratio.

I have 35" tires, same suspension and from what i can tell stock gears(havent physically checked) and no jerkyness.

Also, do you have a Pedal Monster or anything? That will make a difference.

 

[flick2614]

Here is how to figure out your gear ratio.

I have 35" tires, same suspension and from what i can tell stock gears(havent physically checked) and no jerkyness.

Also, do you have a Pedal Monster or anything? That will make a difference.

I'm considering a pedal monster just to see if it smooths out the throttle response.

 

[ALeeL]

One thing that may help is a Pedal Commander or similar product that alters throttle input. I prefer a sensitive throttle on road, but not off road. So, I put mine in Eco mode when I am in 4-low since it makes the throttle less sensitive than stock which gives me better control with less jerkiness.

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[cnapierala]

I'm considering a pedal monster just to see if it smooths out the throttle response.

I have one brand new in a box if you want it? It was replaced under warranty and i didnt re-install it as im going a different direction with my tune. Had that and the Derringer (will also be selling) in mine for awhile.

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