4:56's or 4:88's with 315's ?? (1 Viewer)

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Dec 26, 2008
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Anybody have experience with 4:56's or 4:88's and running 315's? I'd like to be similar to the stock tire size with the factory 4:11's. I think there are ratio calculators out there - 265's and 4:11's is the same as 315's and xxx ?? I still need to do 70 mph but want it to accelerate and crawl better than it does with the 4:11's. Thanks, Ben.
 

jfz80

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Agree with retro but to answer your question 4.56 on 315 should bring back to close to stock. I would opt 4.88 as well
 
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yup, assumed this was the case. Would hate to get the 4.56's in there and always wish I'd gone 4.88. Just don't want it to run at 3,500 down the highway at 70 mph.
 

Joe Link

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I have no experience personally, but did recently regear to 4.88's (haven't driven it yet). I was debating 4.88's vs 5.29's and during my research noted the same thing @retrofive said, lots of people who went with 4.56's and wished they had gone 4.88. It's a huge expense, so you definitely don't want to do it again.
 
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Go with the 4.88. You will regret going with 4.56s. You will barely notice a difference.

Better....get 5.29s and be ready for 37s. You may not know it yet, but that itch to move to 37s will hit you at some point.

I have 37s and 5.29 and I love it. the truck feels prefect with it.
 
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Reading here over the years I generally (not all) think the guys the that went 4.56 were underwhelmed and wished they had gone 4.88. That was my plan before I sold the 80.

totally disagree. i've been running 4.56s for years with 35s and love it. basically takes it back to stock gearing and speedo is close to perfect (285/75-18). i run Marlin TC gears for wheeling and a SC for highway power. gearing is close to perfect for highway and for wheeling. never had wish to go lower and never underwhelmed.
 

Bludozer

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totally disagree. i've been running 4.56s for years with 35s and love it. basically takes it back to stock gearing and speedo is close to perfect (285/75-18). i run Marlin TC gears for wheeling and a SC for highway power. gearing is close to perfect for highway and for wheeling. never had wish to go lower and never underwhelmed.
A 285/75-18 tire is a 33, not a 35. Totally different ball game.
 
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I have 4.88 and 315 works well for me. If I had to say one negative thing about it, it definitely enhances the “Jake brake” effect of the 80 series at highway speeds.

By that I mean, when you let off the gas all that awd powertrain spinning around drags the speed down quick.

It’s just something I noticed not really a problem.
 
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A 285/75-18 tire is a 33, not a 35. Totally different ball game.

huh...?
a 285/75-18 is a 35" tire. the duratracs i'm running are actually a little taller than 35", even more so than the 35.1" specification.


duratrac.jpg
 

lumbee1

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I had all the same questions you did and through research and suggestions of fellow LC club members, I went with 4.88's and think it is the perfect combination. I was nervous about cruising down the highway at high rpms but it's not a real issue. My fuel economy (corrected) has actually gone up since regearing. I would much rather have the engine in the power band rather than struggling with 4.10's with large tires and heavy armor.

Others will disagree but I think 4.88's have been the most impactful change to the Cruiser on and off road.
 
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San Antonio, Texas
Thanks for the question Ben. As a newbie to the forum and LC culture, I’m surprised and pleased at the responses to what I thought might be considered a mundane question. I’m in the same boat with considerations for upgrades this year to my new 80. Questions I would add to this thread for input of this experienced group:

1. WHen I regear, any reason NOT to convert to part time to help reduce the Jake brake effect, among other things?

2. When I change to H151F 5 speed, how much impact will that have on my regearing considerations (will 4.88’s still be the ticket)??
 
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Thanks for the question Ben. As a newbie to the forum and LC culture, I’m surprised and pleased at the responses to what I thought might be considered a mundane question. I’m in the same boat with considerations for upgrades this year to my new 80. Questions I would add to this thread for input of this experienced group:

1. WHen I regear, any reason NOT to convert to part time to help reduce the Jake brake effect, among other things?

2. When I change to H151F 5 speed, how much impact will that have on my regearing considerations (will 4.88’s still be the ticket)??

Just one inexperienced guy's opinion:

1) I don't think the regear would really factor into question #1. Part time is really just a matter of preference, and to be completely candid, I'd suspect most people do it because they can't sort out their driveline vibrations after a 3"+ lift than any other practical reason. Might get a half of an MPG out of it, or your butt-dyno might detect an additional 4 horsepower. Both effects are pretty close to negligible. I like the AWD system for it's idiot-proof-ness in changing Colorado weather. I actually like that my truck slows itself when I let off the gas. I DD an electric car with regenerative braking, so it feels quite natural to me. If you're on the fence, lock the center diff and pull your front shaft and drive around for a week.

2) I personally would do the transmission swap before regearing. See how you like it and then decide. I had a couple stick shift 4-runners with large tires and stock gears and didn't see any need to regear. The manual transmission will give you more options and you may find just leaving it in 3rd or 4th when heading up a grade is a more practical solution than regearing.
 
Joined
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this is awesome. Thanks guys. Some of you existing 4.88 and 315 guys, can you post your 70 mph rpm's ??
 

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