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USMC-SSGT
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- #32
Owner of the shop just emailed me after I placed the order for 4.56.
“ I’d definitely go with 4.88 gears; that 8 speed transmission loves it, and will get you into 8th at a comfortable RPM on the highway. And you are right on the 37s, you’d still be good with 4.88s and 37s, and lots of times we go to 5.13 on 37s.”
This makes things interesting. Besides all my research telling me 4.56 will accomplish exactly what I’m looking to do…4.88 is still recommended. Shops ALWAYS seem to say 4.88. Now I can’t decide if I’m more confused than a fart in a fan shop or a chameleon in a bowl of skittles.
Plus side when you’ve neared the end of your research- both options are so appropriate that you can’t actually be “wrong.”
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Wheelin98TJ
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- 2021 Jeep Gladiator
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4.88 cause you’re still good on the highway. No benefit with 4.56.
Owner of the shop just emailed me after I placed the order for 4.56.
“ I’d definitely go with 4.88 gears; that 8 speed transmission loves it, and will get you into 8th at a comfortable RPM on the highway. And you are right on the 37s, you’d still be good with 4.88s and 37s, and lots of times we go to 5.13 on 37s.”
This makes things interesting. Besides all my research telling me 4.56 will accomplish exactly what I’m looking to do…4.88 is still recommended. Shops ALWAYS seem to say 4.88. Now I can’t decide if I’m more confused than a fart in a fan shop or a chameleon in a bowl of skittles.
Plus side when you’ve neared the end of your research- both options are so appropriate that you can’t actually be “wrong.”
OP
OP
USMC-SSGT
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- #35
Honestly this is the kind of stuff I live for anyway. I get more enjoyment out of the research and the build than the finished product. Once the project is “done” or run its course im ready for the next one.
The minute my truck goes in the shop for gears I’ll be starting a thread on the next thing. Maybe Borla vs AWE…….
The minute my truck goes in the shop for gears I’ll be starting a thread on the next thing. Maybe Borla vs AWE…….
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JerseyMark
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I vote 4.88s over 4.56 gears
My brother has a 2021 JT Sport w/ 8spd auto, he has 315/70R17 KO2s on it(so small and light “35s”). He had originally planned to go 37s, so he regeared to 4.88s. He ended up staying with the 35s. I have driven it a bunch of times and I think it drives perfectly. Excellent performance, big improvement in city driving mpg and highway mpg is still good. Basically, he noticed no real downside with 4.88s and is glad he did not do 4.56 gears.
My brother has a 2021 JT Sport w/ 8spd auto, he has 315/70R17 KO2s on it(so small and light “35s”). He had originally planned to go 37s, so he regeared to 4.88s. He ended up staying with the 35s. I have driven it a bunch of times and I think it drives perfectly. Excellent performance, big improvement in city driving mpg and highway mpg is still good. Basically, he noticed no real downside with 4.88s and is glad he did not do 4.56 gears.
OP
OP
USMC-SSGT
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- #37
That’s helpful thank you. Always good to hear the real world experiences. Conclusion seems to be that:
1: 4.56 is a great choice and would work out well.
2: 4.56 would also work out well with 37’s. But about as well as 4.10 gears and 35’s. Perfectly fine…but not ideal.
3: 4.88 checks all the boxes, and is no noticeable difference between them and 4.56. A better choice for 37’s, towing, if the Jeep gains weight.
Seems like after already buying 4.56 13 hours ago… I’ll go with 4.88 as I cant go wrong. Now, if someone was like “that’ll easily cost you 1-2 mpg more” I may reconsider. I only drive maybe 800-1000 max miles a month. Of that it’s maybe 300 highway.
Tufelhundin
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Hey Devildog I went through this exact ordeal and like you the research was probably the funnest part, lol.
I run 315/70-17 Copper STT Pros and ended up going with 4.56. I truly believe you will be fine with the 4.88's. I dont tow much other than a pipe 16' tandem with a UTV or a zero turn...or both.
With stock 3.73 and these tires I stayed in 6th gear at speed 55mph+, with the 4.56 it will go in 8th jut after 45mph. It stays at right at 2k rpm at 65mph and I have the speedometer corrected to with-in .5mph
I have numerous post on these gearing threads concerning my setup, I have zero remorse with my choice of gearing, however I know for a fact 37's are NOT in my future and I really dont see me towing much more than an aluminum bass boat in the distant future after I retire
I run 315/70-17 Copper STT Pros and ended up going with 4.56. I truly believe you will be fine with the 4.88's. I dont tow much other than a pipe 16' tandem with a UTV or a zero turn...or both.
With stock 3.73 and these tires I stayed in 6th gear at speed 55mph+, with the 4.56 it will go in 8th jut after 45mph. It stays at right at 2k rpm at 65mph and I have the speedometer corrected to with-in .5mph
I have numerous post on these gearing threads concerning my setup, I have zero remorse with my choice of gearing, however I know for a fact 37's are NOT in my future and I really dont see me towing much more than an aluminum bass boat in the distant future after I retire
OP
OP
USMC-SSGT
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- #39
More real world input, thanks war dog. I think you’re right and I tow even less than you. The only wild card now is if someone stole my wheels in da hood- I’d likely order 37s as replacements. I have zero plans to go 37, and “wont” (unless I do) just replace my killer Baja boss set. That being said…when they do get replaced I’ll be researching stepping up to 37s (to look cool) as much as I’ve researched this. Mostly because with my lift the 35’s ALMOST look a bit small.
Tufelhundin
Well-Known Member
Here is my RPM’s at 70mph
I just took this picture not 30 min ago heading into town
I just took this picture not 30 min ago heading into town
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Deleted member 22728
4.88 gas, 4.56 diesel or Hemi. Ask the man who builds them.
OP
OP
USMC-SSGT
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Are you the guy that builds them @1979WagoneerLTD? Where were you by post number 2?! Could have saved some back and forth.
Deleted member 22728
Because Maker's Mark and diet coke sometimes make violent lovers.
Seriously, tho, with any incarnation of the 3.6 or 2.0, 4.88 when combined with 37 or 38", reliably restores "factory" drivability. Eco and big fat hemi, 4.56 is more than sat with the rig.
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