4.56 is the 37 equivalent for stock gears on 33’s. 4.88 is one step, 5.13 is 2. Its about 150rpm more at highway cruise on 5.13 vs 4.88.
imo listen to your shop. They know what they run in their jeeps and what people in your area have asked for and been happy or not with...and 4.88 is certainly well within Normal range for 37’s.I’m stuck with this same decision. I’ve had 37s on my automatic Overland with 3.73 gears for several months, and it’s killing me. My Jeep has forgotten it had an 8th gear.
There’s a very slight possibility I may upgrade to 38s down the road, but I will never go bigger than that. I’m at sea level and do mostly highway driving with some beach driving and plan to tow a small boat or jet ski this summer. My sister-in-law is in the mountains, and we visit her about twice a year. I have a 30-minute commute each morning, so I do care about mileage (as much as any Jeep owner could). My local off-road shop recommends 4.88, but I’m torn between 4.88 and 5.13.
I'll just drop this here. I created it using Grimm Jeeper's Gear Ratio site and specifically for the 8-speed 3.6L JL/JT as the other tables out there are for the JK and do not apply.I am out of time and need to make a decision, the more I read the more I succumb to analysis paralysis.
Running 37” ridge grapplers with 3.6 and auto trans. Currently about 1500’ above sea level with trips in the future to Colorado and utah hopefully. Very rare towing but occasionally my CJ7 on a car hauler. Not a daily driver but weekend toy and bug out vehicle only.
4.88 or 5.13 ???
Living in Alberta we’re in winter half the year and wet for another 3rd, lol. So I’m not as concerned about a smaller pinion gear than in a dry Ricky climate. Thanks for your input though.TR went down to 4.88 and said it was better.
i usually agree with “you cant go to low”, but decided after much deliberation and consideration of pinion head sizes to go with 4.88.
See now I’m in Edmonton, Alberta which is around 2,000 ft (600m) amd I often go towards the Rockies to go wheeling!Went with 4:88 at sea level...couldn’t be happier with the 37s it should come with these from the factory...I would recommend doing it even if your running 35s
Appreciate it, I’ve seen a few charts and eventually plan to go larger tires, so I’m happy with my decision to go 5.13, now I just need to get them installed. Being unemployed makes it difficult to allocate the fundsI'll just drop this here. I created it using Grimm Jeeper's Gear Ratio site and specifically for the 8-speed 3.6L JL/JT as the other tables out there are for the JK and do not apply.
No prob. Sorry to hear about being out of work; hopefully you'll find something soon. Sending good vibes to my Albertan neighbour!Appreciate it, I’ve seen a few charts and eventually plan to go larger tires, so I’m happy with my decision to go 5.13, now I just need to get them installed. Being unemployed makes it difficult to allocate the funds
Should be back to work in the next two weeks in FMac. So gears are in and I’m loving it in 8th gear all day! However, my lockers have malfunctioned and I’m going to be dropping my fluids and pulling the magnetic sensor out and cleaning it off as I’ve read that some magnetic particles can apparently interfere with the sensor. Will let you all know if that’s the problem.No prob. Sorry to hear about being out of work; hopefully you'll find something soon. Sending good vibes to my Albertan neighbour!