Just completed 5200 miles round trip in two 100 series Land Cruisers from Florida to Montana and back. What an adventure to “The Big Thing” at X Overland Ranch. Our two rigs have 2” Iron Man suspension lift with 32” General ATX tires. Built out inside with Goose Gear….. we had a bit of a challenge on the long grades uphill. Sometimes having to drop into 2nd to keep pulling, 4000 + rpm. No fun to say the least. It was suggested that regearing should be considered. Questions. Who has done it? In the USA, who is the best. Ill drive there. No matter where. Which ratio gear did you get? What is your rpm at 75 mph? Any other issues, suggestions or ideas. Thank you much. Dan. Family X Overland.
Regearing 100 series. Thanks
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family: it would help us understand if you put rig specifics (year, etc) in your signature. are we talking 4 or 5sp tranny, newer motor, etc.
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My apologies. We have a 1998 Land Cruiser and a 2001. 4 speed with OD
It helps a little. I have 4.88 gears in a 99 and still have to use 2nd to get up the hills in Colorado.
hoser
SILVER Star
The only difference gear ratio available without some extra work is 4.88. IMO, it would be geared too low for 32’s for cross country travel. RPM’s would be 4.88/4.3=1.135…. Multiply that by your cruising speed RPM.
However, there is a 10% underdrive high range transfer case gear that would be more appropriate. Can also swap the LOW range gear if desired.
However, there is a 10% underdrive high range transfer case gear that would be more appropriate. Can also swap the LOW range gear if desired.
I did the 10% underdrive on my 2002 and it made all the difference in the world driving in mountains, in the east anyway. RPM`s increased by only 400 and no change in fuel milage. My loaded weight is 7600 lbs.
Now I can make it up about 3/4 of the grades without a downshift. It will still kick down on the sreepest grades though but previous to the gear change I couldn't even use cruise control effectively in Florida, it would kick down on the slightest incline.
FYI, the transfer case weighs 105 lbs, so a proper jack adapter is required.
Now I can make it up about 3/4 of the grades without a downshift. It will still kick down on the sreepest grades though but previous to the gear change I couldn't even use cruise control effectively in Florida, it would kick down on the slightest incline.
FYI, the transfer case weighs 105 lbs, so a proper jack adapter is required.
As hoser said, there is no 4.56 gear set available for the 100 series, which is where you would want to be with 32s. 4.88 would definitely be too low.
Assuming you are already using the PWR setting to adjust the shift points, the next step would be adding an under drive.
Assuming you are already using the PWR setting to adjust the shift points, the next step would be adding an under drive.
hmm, in my '04, never really noticed hill struggles. that includes "loaded for bear" trips to co from ca. I usually cruise at 65/70.
I'm about to go on a massive hwy based trip around the west. I'll pay more attention and report back.
I'm about to go on a massive hwy based trip around the west. I'll pay more attention and report back.
What year is your truck / do you have the 4 or 5 speed transmission.....In my opinion this truck is not meant to blast up mountain passes at 75mph with ease like the modern vehicles can, you will certainly be running higher rpms like you mentioned....This doesn't mean you need /should re-gear, just means when you're out west trying to climb the passes, don't let the pickup trucks and big diesel rigs blasting by doing 80mph bother you, just slow it down and cruise..
hoser
SILVER Star
The difference with gearing will be noticeable but not drastic. If you are willing to spend the coin, an Elate supercharger would make a bigger improvement.
just lucky it's not a 60....I 70 heading east from I15...30mph in 2nd with semi's passing me 
This was my experience going through mountain passes i15 South heading back to Vegas from Salt Lake City UT where hiway speed limits was 80mph. On stock gears 06vvti with 5-speed, loaded with around 300lbs of gear, 35x12.5 tires, front bumper, lights and winch, temperatures gotup real fast. Depends on the grade rating %, I drop a gear down to 4th, maintain the speed 65mph and AT Torque Converter temperature goes down to 175°F (from 200°F), coolant temp goes down to 194°F (from 198°F). And this was the truck running lean with intermittent P0171 dtc. Regearing will definitely help keep these temps down.
When cruiser outfitters built my diffs with lockers they put 4.30 gears in them. I have a 07 with 32.8” tires so the stock gear ratio is 4.10
4.30 would bring the driving characteristic closer to factory. 4.88 is overkill unless you’re going to like a 34-35”+ tire.
4.30 would bring the driving characteristic closer to factory. 4.88 is overkill unless you’re going to like a 34-35”+ tire.
Exiled
SILVER Star
I've spent a ridiculous amount of time researching gearing, primarily comparing the benefits of regearing the diffs vs. regearing the transfer case. For background, mine is a '99 which has stock 4.30 gears in the differentials and came with the weaker 2-pinion front diff and the factory rear locker.
Here's what I decided to do. After grenading the front diff on a trail in Moab, I bought a newer front diff with the 4 pinions and will be adding an Eaton locker to further reinforce, keeping the stock 4.30 ratio. I'm going to add a 10% underdrive to compensate for the 35's I'm running, and then add the Sumo 3:1 low gear from Cruiser Outfitters. Also going to part-time 4WD while I'm out there, in case I grenade another front diff. The main reason to focus on the transfer case vs. the differentials is that I wanted the lower crawl gear and if I was going to be cracking the t-case open, might as well add the underdrive. Not saying this is better than just re-gearing both diffs, just that it seems like the best solution for me.
Here's what I decided to do. After grenading the front diff on a trail in Moab, I bought a newer front diff with the 4 pinions and will be adding an Eaton locker to further reinforce, keeping the stock 4.30 ratio. I'm going to add a 10% underdrive to compensate for the 35's I'm running, and then add the Sumo 3:1 low gear from Cruiser Outfitters. Also going to part-time 4WD while I'm out there, in case I grenade another front diff. The main reason to focus on the transfer case vs. the differentials is that I wanted the lower crawl gear and if I was going to be cracking the t-case open, might as well add the underdrive. Not saying this is better than just re-gearing both diffs, just that it seems like the best solution for me.
hoser
SILVER Star
This is the route I sometimes think I should have gone. The part-time kit is great and I like the driving characteristics. The only downside is when I'm driving from the Denver area heading west into the mountains. It will be clear and then get nasty real quick. I have managed quite well so far, but I have had a few white knuckle moments.
I have only locked the front hubs while out at Moab. Been unlocked since late last winter.
Essentially the same path I've taken, except I installed the 4-pinion before our March Moab trip and blew it up at Moab Rim (rated 7).
I'm building a spare set of front and rear diffs with ARB lockers and adding 4.88's to the equation. So now, with the 10% UD I'll be 5.35
I can say that the 3.1:1 low range is hit or miss. The 4 speed shifts very hard I need to rev it out during a climb. I find myself staying in high range most of the time now. The 4.88's plus the 10% UD will allow me to use high range for a lot of trail use, and use low on really steep slow grinds.
hoser
SILVER Star
Unless you are going to 37's, I'd reconsider that 23.5% underdrive.
