4.88 with 35s is a TON of gear. It was probably great in moab. But you will want to kill yourself in daily driving situations if traveling distance on highways.
Thats the whole thing with the north east. if you live here and want to really wheel, you have to be prepared to do 3 hours in the car. Knowing that you are overgeared and that 3 hours is going to be miserable with your truck spinning at 3k rpm to keep up with traffic, you will talk yourself out of wheeling all together. You need a blend of highway and offroad. Thats why the transfer case is a reason to get a rubi. You can maintain good off road gear, in 4LO but still have a livable truck on the highway.
Last edited by JeepLab; 09-20-2014 at 09:21 PM.
So let me know if I get this right.
SC + AUTO + 35s + 4.10 gearing = highway passing in 4rd gear?
SC + AUTO + 35s + 4.56 gearing = highway passing in 3rd gear?
Now, this all brings further questioning
1. Is your speedo calibrated perfectly?
2. What is the RPM you cruise at if doing 80mph?
baumann, Ive read your posts a bunch of times now trying to get clear about how to help the OP in this thread. Since you have the auto with the mag and we dont, your experience above ours in this case because of your AUTO transmission.
Here is what I think about your situation, not Jt1911's.
I think are geared right. 4.10 for 35s with the SC is PERFECT gearing. If you had 4.56, you would feel overgeared. If you have never been overgeared, take it from me. It sucks. Do not feel like if you did it over again, you'd do it different. The grass is always greener on the other side of the fence. I promise, you are on the greener side of the fence. Being overgeared, turns your supercharged truck into a pig on the highway. I dont care how much horsepower you make.
If you had 4.56 with 35s on an Auto, you would be at 2700 RPM at 70 MPH! Your truck would struggle to get to 80, and would be gasping for air there at 3500 RPM. You would almost be forced to go to 37s.
Just my position. take it from a guy who geared twice.
Last edited by JeepLab; 09-20-2014 at 09:28 PM.
Now back to you Jt1911,
SC + AUTO + 37s + 4.10 = good drivablilty. Would it be better with 4.56? Maybe.
My own truck BB is
SC + Manual + 37s + 4.56
Do I love it? I'll tell you this. I hated the 4.88s. Took my rocket ship and turned it into a row boat. I struggled to get to 80 MPH, really struggled. Made me sick to drive her.
Is she now at 4.56 the highway cruiser she was with 4.10? when I'd cruise at 85mph at 2300 RPM in 6th gear? No. Ive lost her awesome effortless cruising speed. even dialing back to 4.56s. I cruise at 75 now.
Everyone's perception of what is "Good" is different. Jesse (snarf) and I have very similar builds, but we go in opposite directions on certain points like gearing. He likes more gear than I do. But he is also the kind of guy who dosent mind back roads. If im not on a highway cruising at 75 at least...I'm pissed.
You dont know what gear YOU will like until you live with gearing for a time. I say, live with your 4.10s for a while. If you hate it, consider 4.56. People will tell you, "if you want 4.56, you should just go to 4.88" Thats BS.
If you have 37inch KM2s, then look at the 35 inch line of the gear chart. And pick your gearing by where you want to cruise on the highway. You have a rubi, so your transfer case will make whatever gear you have 4.10, 4.56, 4.88 , low enough to wheel with anywhere in the united states.
[QUOTE=JeepLab;3125]So let me know if I get this right.
SC + AUTO + 35s + 4.10 gearing = highway passing in 4rd gear?
SC + AUTO + 35s + 4.56 gearing = highway passing in 3rd gear?
Now, this all brings further questioning
1. Is your speedo calibrated perfectly?
2. What is the RPM you cruise at if doing 80mph?
baumann, Ive read your posts a bunch of times now trying to get clear about how to help the OP in this thread. Since you have the auto with the mag and we dont, your experience above ours in this case because of your AUTO transmission.[QUOTE=JeepLab;3125]
OK.
SC + AUTO + 35s + 4.10 gearing = highway passing (65 mph to 80 mph) in 3rd gear. I use auto-man to go to 3rd and that lets me get the throttle open enough to get boost up. 4th gear is problematic when passing. Even in auto-man if I pass in 4th gear the trans will downshift when accelerator is depressed beyond a certain point. It won't stay in 4th. The downshift from 4th sometimes jumps two gears to 2nd! That's not safe for me or the motor. So to stay safe I go to 3rd. Yes, I can pass in 4th but it takes much more distance and not at all uphill. Again, there is probably more power available in 4th gear but I can't access it because opening the throttle enough to close the SC bypass and get into full boost will cause an unwanted downshift. I'm thinking that 4.56s will get rpms up in 4th a bit and reduce the downshifting. A better solution would be to get access to the transmission side of the PCM and reprogram automatic trans shift-points and keep my 4.10s. But I hear that's not going to happen for a long time if ever based on how difficult it is to crack Chrysler's PCM transmission programming.e
I'll record my rpms at 80 today and report back.
Hey guys, sorry for the delay with pics, work schedule has been crazy. Thanks again for continued information. One of the things I wanted to wait and see what effect there was, was throwing the GOBI rack on top. One thing that I've been thinking about was how much weight I've added to my jeep. I installed the rack just yesterday and I love it, but man that thing is a pig. I was able to drive the jeep for two days without the rack and a short road trip yesterday with it.
I thin the added weight from everything is something that has pushed my decision to go with 4.56's. Now, I do not spend a lot of time on the hwy and when I did, I wasn't hammering 80mph regularly. Most of my driving is backroads. That being said, with the terrain around here, there's a lot of up and downs and I was annoyed at how I had to push up to 4500 rpm to get a gear change. But, The SC wil be getting installed in two weeks and I'm goon wait and see how she does with 4.10's and then I'll make my mind up at that point.
So.. for pics, can anyone chime in with simple directions? never posted pics before..
Figured it out..I think
Connect With Us