After just under a year with 35s and 4.10 gears, 4.88s were installed about 2 weeks ago. Yes - 6th is back, but now questioning the use of 1st lol.
Major differences that I notice:
1. Before change, not much power or acceleration below 2,000rpms. Now comfortable acceleration at 1,500+roms.
2. Before, motor bogging down in 4H in the sand on the beach so 4L was mostly used. Now 1st & 2nd in 4H easily derivable.
3. Starting at the green light you just about put it into a gear and it is time to shift again.
4. Played a bit flexing on a stump in 4L. 1st gear with the Rubi 4.1 transfer and the 4.88 gears - didn't even need to press the gas, just idled up it.
Anxiously awaiting g3/31/17 when the local wheeling spot opens to really check it out. You going from 3.21s should really notice a big improvement.
Acceleration is awesome. Duratracs 315/70/17. rpm@ 60 mph = 2300, rpm@ 65 mph = 2500, rpm @ 70 mph = 2700, rpm @ 75 mph = 2900. It was a tad higher than expected but pulling my cargo trailer or boat is now exceptional, and I look forward to going to the mountains. Without towing I may lean toward the 4:56s and my rpms are with manual trans so the auto will be 100 higher.
So there are a few times in life when it felt like I had a new Jeep
1. When I got a new Jeep
2. When I got a lift
3. When I got tires
4. When I got gears
Acceleration is awesome. Duratracs 315/70/17. rpm@ 60 mph = 2300, rpm@ 65 mph = 2500, rpm @ 70 mph = 2700, rpm @ 75 mph = 2900. It was a tad higher than expected but pulling my cargo trailer or boat is now exceptional, and I look forward to going to the mountains. Without towing I may lean toward the 4:56s and my rpms are with manual trans so the auto will be 100 higher.
This is very help full. I have been looking for rpm numbers with 4.88s and a 6 speed with 35's or 315's to help me decide which gears to go with. Your post has me leaning towards 4.56's as I DD my Jeep about 70-ish miles per day.
2,500 rpm @ 65 with 4.88's is a far cry from the 1,900-2000 rpm's I am seeing with 3.73's @ 65 with 315's. I am thinking 4.56's will have a nice sweet spot for the engines power band and mpg's.
I'm doing number 4 Monday. 4.56 on a 16 JKU Sport with 3.21 gears and auto. I'm looking forward to more instant power, closer shift points and less winding.
Also 1000-1200 rpms cruising at 40 is getting annoying
I'm doing number 4 Monday. 4.56 on a 16 JKU Sport with 3.21 gears and auto. I'm looking forward to more instant power, closer shift points and less winding.
Also 1000-1200 rpms cruising at 40 is getting annoying
I went 4.88 for 37s and regret not going 5.13.
So IMO 4.88 is aggressive for 35s, but OK if you're on a D44. A D30 personally I'd stick with 4.56 for the extra strength. The R&P is much smaller on a D30.
I think 4.56 is the best overall gearing for 35s on the 3.6 unless you're towing in the mtns. I was going to get one of the two before I decided to not tow with the Wrangler. Now I just get annoyed with 4.10s while going up the mtn passes.
The 4.88s will be far more enjoyable than the 3.21.
I think 4.56 is the best overall gearing for 35s on the 3.6 unless you're towing in the mtns. I was going to get one of the two before I decided to not tow with the Wrangler. Now I just get annoyed with 4.10s while going up the mtn passes.
The 4.88s will be far more enjoyable than the 3.21.
The 4.88 seems really nice so far. I am breaking them in for the next 200 miles. The tranny switches gears so much smoother and there is no lag in 1st. So far so good. At least I am ready if I ever decide to go 37" tires.
I run 4:88's with 40"s and it is just right.
The only time I need more is in the Mountains and then it's not the gears, it's lack of engine and that's when I need an LS3
I went with 4.56's and couldnt be happier. I only have 33's, with no immediate plans to go any bigger. Even if I would go to 35's one day, the 4.56's would still be plenty fine, especially with my 6 speed. I gained 6th gear, but as posted above, I think I lost 1st gear in the process!
This is why I am going with 4.56. If I ever had to have a 3rd back surgery..god forbid, dropping to a 33 from a 35 would be perfect height to slide into the seat. Now is still ok. Leg lift and slide lol
Just had my 3.73's swapped for 4.88's. Tires are 315's. Been driving for a week now and it's great. I went back and forth on the decision between 4.56 and 4.88 and feel like I made the right choice. Looking forward to getting on some dirt after the break in period and seeing how it does with the 4:1 transfer case and new gears.
WOW. Now I'm very confused. c-ouch:
Should I go for 4.10 or 4.56? or...
Mine is 3.8 : drinks: on 35's.
I drive 40% highway, 20% city, 40% offroad
Highway is a pain, at 75mph (cruise control) never use passing gear, always changing to 3rd, 4, --- 2nd gear sometimes to keep speed. (transmission getting hot sometimes).
The Jeep is an Auto. I am still really light on the gas pedal as I still want to get 17mpg. It was the first time I pressed pretty hard as I was trying to get my wife to the airport quickly. Might be normal
The WA580 transmissions only have 5 forward speeds. Post up if it does it again. The only things I can think of that would cause the engine to rev on a 4>5 upshift would be a failure to hit 5th - unlikely - or the torque converter unlocking. I don't know these trannies well enough to know how unusual that is, but it doesn't seem right.
The WA580 transmissions only have 5 forward speeds. Post up if it does it again. The only things I can think of that would cause the engine to rev on a 4>5 upshift would be a failure to hit 5th - unlikely - or the torque converter unlocking. I don't know these trannies well enough to know how unusual that is, but it doesn't seem right.
So a friend of mine was telling me this normal. The same friend stated that when this happens and you let off the gas that it should shift. I actually changed the tire via my procal to 34 from 33.75 and it helped a little. I wanted verify how much it shifted the shift points. It is definitely different but does happen from time to time.
Dropped my 2dr auto off at the shop this morning to get 4.88s installed. I just didn't like the 4.10s with the 315s at all. I drive mostly rural and suburbs and going up hills and such was not to much fun.
How fast are you going when this happens? As I mentioned in your other thread (that was you, right?), your setup translates to 80-100mph at 4-5krpm in 4th gear. Assuming you're not going that fast your torque converter is unlocked, and making heat, or you're not really in 4th gear.
I am going in between 50 to 65. Usually happens before getting to 70mph cruising range. But if I take my foot off the gas when it happens then it all goes back to normal and the jeep continues to accelerate normally.
Some good info here. I'm looking at 37s. I have a 2014 jku rubicon x with 4.10 gears. I have 3.5" lift to go on it. Should I go with 4.88s or 5.13s? Also it's a dd.
In your other thread on this, you were going to verify:
1) Your gear ratio is entered correctly with the ProCal
2) The weighted rolling diameter you entered for tire size
3) Whether your speedometer matches an external (not the one in the radio) GPS
Using the AEV procal i verified the gear ratio is set correctly.
Tire is set to 33.75
I checked on my GPS on myphone and the phone is stating 1mph slower than the speedometer.
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