re-gearing to 4.88's question

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Dec 4, 2016
on the road again....
I'm about to do lockers so now is really the time I should decide whether to re-gear.

I'm not going over 34" tires or messing with the KDSS. Will most likely end up around 33.5 with STT Pros.

Is the general consensus when I get into mountains and hills and away from flatland the tranny will do a lot of searching for gears??

I'm getting pretty good gas mileage here in flatlandville even though I drive fast and punch it a lot.
15-ish in mixed freeway and city streets and 19-20 on the highway usually @ 70-80.
That is pretty much the same as all the 4wd V8 trucks I've had....or actually a bit better with the cruiser in mixed driving.

I guess 4.88's will drop my mileage a bit on the highway here...and then probably help in the mountains?
Has that been peoples experience???

I'm doing aluminum skids to cut back on weight and also removing the 2nd row seat. When I build a storage compartment to fill in from my front seats to my Arb drawers I'll keep it lightweight also.

Kinda talked myself into doing 4.88's already I guess... :)

What RPM's will I see around 75mph?
No way would I spend the money to re-gear on basically stock size tires. I run BFG KO2s in 286/6518, which is about a 32.5 inch tire. Feels like a Ferrari compared to my 80 series that runs on 35s with stock gears.
I regeared with 33s and am glad I did. I have a heavy truck, though.
Geez it is hard to know the real diameter of what a tire will really be. They may list it at 34.35 and it may end up being 34 or 33.80.
Really need to buy from someone that will mount one and see if it rubs and where when you are really cutting it close like I am.
Could hit a UCA or could be something I can trim.
I'm doing SPC UCA's....and that is most likely going to be my rub point from what I have seen and read here.
Ahhh good to know Cooper is listing accurately. Wish I had 17" wheels.
I'm starting to feel like I'm throwing around thousand dollar bills like chewing gum wrappers.
Trying to just be content with my stock 18's. :)
Gears are pretty optional if you stay close to 33" and in TX.... at 35" and in CO I was hating it.... very glad I did the 4:88's.....

but under that you likely could be happy...

I agree it really can be frustrating figuring out what tires will measure once actually mounted. For example... My 35x12.5x17 are almost exactly 34...aired up and off the truck. So basically like @TonyP ’s Coopers...but wider.

But there it is...a “35” that is 34” tall.
Makes calculation gears and tire revolutions feel uncertain for sure.

As for me...I unquestionably want/need a gear swap. Like Cole said though (and others like Taco), an fully built and armoured 200 really does benefit even with 33’s due to weight & drag...not to mention larger tires. -Just a question of funds for me. Definitely going 4.88 here.

PS. And ya...Taco has convinced me about the heat/torque converter issue.
Would rather keep heat & wear down, and take full advantage of my top gear when possible.
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well if your Nittos are rubbing and are actually 34. I better go a little under 34. I remember your story about getting the tires and rubbing a lot on your way over to Slees :)

I can already see I'm going to re-gear for multiple reasons.
So I view gears a little differently than some. All I care about is keeping the torque converter locked on the highway. While the 5.7 has a ton of power, it doesn’t have enough at 1600 rpm to keep a modified 200 going down the highway with some small hills.

Living in West Texas, with just a winch bar and a lift, still stock street tires, the loss of aerodynamics alone made staying locked in 6th kind of annoying.

Once my STT Pro 295/70r17s (33.5”) tires went on, forget about it. 6th was a distant memory. As tested from El Paso to LA then Denver and finally Savannah.

I went down to 10 mpg highway. Then I added 4.88s and came back up to 13 mpg.

So for me and my attention to when the T/C unlocks and build heat like crazy makes me feel that gears are pretty important. But that’s me, we all have what we want out of our trucks, I just really hate excess wear on components, especially drivetrain, since when something goes wrong, it’s me fixing it.
yup..with ya on that Taco. Been thinking about drivetrain stress also. Crazy not to re-gear when I have it torn apart for lockers.
I'm not aiming for tall tires....just as much as I can get without a hassle. With the STT Pros and my 18" wheels looks like 33.31's which is cool with me. There are more size choices if I went with Toyo open country or something else but I've had Coopers before and liked them.

I'm foreseeing a lot of mountain time in my future so the re-gear makes even more sense.....and meeting you guys on some outings for some mischief, beer and laughs will be a riot too.

I'm taking my rig to TT (Jason) the end of Jan. for bumpers and a winch. I suspect when I pick it up since I am way up there I'll do some exploring and see some places I haven't been before I head back down here to the equator and deal with the bills for all this obsession. :)
well if your Nittos are rubbing and are actually 34. I better go a little under 34. I remember your story about getting the tires and rubbing a lot on your way over to Slees :)

I can already see I'm going to re-gear for multiple reasons.

My Nittos are 12.5" wide though... That's quite a bit wider than a typical 285/75/17 that is 34" tall. So ya, mine were rubbing like crazy while turning through those few miles to Slee from the tire shop, but only because I still had the tupperware bumpers on, and hadn't yet moves things around via alignment fiddling, etc. :) All good now. If I turn full lock, it barely touches the sway, but nothing I worry about. Really very happy with the size. My only complaint is I want slightly larger voids on my next tire...but that's another matter.
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well...flatland, stock vehicle. Haven't destroyed the aerodynamics yet with a lift or bumpers. But now I am about to.:)
Several people have reported 19-22 @ highway speed with 200's. I try to keep the rpm at 2000 or less. Speed limits here are 75 on many highways and if you drive 75 many people pass you. :))
I've had a surburban and several chevy 4wd trucks that would get 20 - 22 @ 70. All mine have for 30 years actually and my Dads.
I had a Dodge truck with a 5.7 hemi that was almost as good. But it was an 8 spd.
On the down side my Turbo 911Porsche with AWD gets about 10 mpg when I ride around punching the go pedal....and it is hard not to.
But it will get 25 on the hiway if I act civilized. :)
Most of these idea wars are fought in our heads not in the truck. You can just run the transmission in manual mode, limit top gear, ensure that it locks the converter and motor will laugh at you for worrying about wear and tear. After dark around the campfire it is a different story. In 40 years of land cruisers almost all the things I modified look pretty silly in hindsight. At the time it was clearly life or death. Of course, that is just my version of the story.
Hmm. I see 4.88 tea leaves. The 200 is a giant compromise. But a very thoughtfully executed compromise. The driver is the key. The ultimate mod. I sought to be the devil's advocate and point our that there are many ways to skin a cat. I have re-geared in the past and there are many pluses. Especially if you live above 8,000 feet of elevation.
I think the real question is how in the hell are you getting 19-20mpg going 70-80mph?????
When my 200 was stock, I got 19 mpg at 82 mpg all day. Rolling hills and all. But modified, never see that economy again.
Couple years ago I averaged 18.5 n my drive from San Diego, CA to Wisconsin and back, and that was with sliders and 33's, dual battery, my 250lb uncle and my trucked LOADED to the ceiling. Same average to Texas and back.

When it was fully stock, I got just over 19 highway.

Now? Built heavy and bumpy...highway I might get 14+ highway depending on how I drive.
Around town...I'm lucky to get 11.

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