gearing and 255/85 tires

[mvbeggs]

Mvbeggs,
I spend half the year or more traveling, mostly the western states. I'm familiar with virtually all the rocky mountain grades. My trailer weighs 2350 on the axle with 225 on the tongue for a combined truck load of around 600 pounds with gear. I have the 4.56 gears with 235/85-16 E rated tires (approx 32"). My unloaded truck weight is 5350 with a full tank, me and 2 dogs. I also towed this combination with stock gears prior to the switch. At 65 I'm turning 2550 RPM in high gear (manual 6 spd). With the 255s you would need the 4.88 gears to approximately match what I have....<snip>

Hope that helps....

That is EXACTLY the kind of information I need. Thank you for the in depth, response. Your entire response really gives me something to sink my teeth into.

....At 65 I'm turning 2550 RPM in high gear (manual 6 spd). With the 255s you would need the 4.88 gears to approximately match what I have....

I may have to live with some downshifting on the steep grades. (After gearing and tires, it looks like 4th gear in the auto, 1.00 tranny gear ratio, would put me at about 62mph at 2550 rpm.) I'm concerned the 4.56 or 4.88 gearing would kill me, and the gas mileage, coming across the flats of Kansas and Colorado at 80mph. What kind of gas mileage are you getting in your access cab? One of my main goals for a Tacoma build is to increase my range over the Jeep's.

....There is one issue though that is probably not common knowledge. The weak link in the towing ability of the 4.0s is the rear diff. Both the 8" and the so called "8.4" measure 8". That is a really marginal gear size for the power of the 4.0 under high loads. When I swapped gears after just 20K of combined towing my carrier bearings were already showing evidence of spinning....

Good to know. I wouldn't have thought that about the rear diff. Too bad they don't build the Tacoma as stout as they build the Tundra. Great intel on the operating temps in the rear diff. So, am I correct in guessing, you wouldn't recomend supercharging the 4.0 in fear of totally annihilating the rear diff? :ylsmoke:

 

[downhill]

I may have to live with some downshifting on the steep grades. (After gearing and tires, it looks like 4th gear in the auto, 1.00 tranny gear ratio, would put me at about 62mph at 2550 rpm.) I'm concerned the 4.56 or 4.88 gearing would kill me, and the gas mileage, coming across the flats of Kansas and Colorado at 80mph. What kind of gas mileage are you getting in your access cab? One of my main goals for a Tacoma build is to increase my range over the Jeep's.



Good to know. I wouldn't have thought that about the rear diff. Too bad they don't build the Tacoma as stout as they build the Tundra. Great intel on the operating temps in the rear diff. So, am I correct in guessing, you wouldn't recomend supercharging the 4.0 in fear of totally annihilating the rear diff? :ylsmoke:

My stock gas mileage was 18 MPG. That was stock gears and close to the stock 4,000 weight. Now I'm getting 16 running empty with 1,000lbs additional weight. Add the trailer and gear and I'm down to about 13 in the mountains, 14 over rolling terrain. I very rarely ever see flat land, so I don't have good numbers for that.

Most manufactures size the diff according to power output and expected load. Toyota got it right for the smaller engines, but when they went to the 4.0 they did not upgrade the diff along with it. IMO that was a big mistake given the substantial increase in power. I think partly it was because they targeted this truck for urban use and figured they could get away with it. They were also trying to run up the MPG numbers for sales reasons. That's why they hobbled it with 3.73 gears too. That's all my conjecture of course, but I'll bet it's close. I've heard of these diffs being burned up with supercharged 3.4 engines towing on grades. If I saw the need to supercharge mine, I would include the cost of a Dana 60. Honestly though, I think the 4.0 is a fabulous engine for these trucks. If I really needed more I would probably just buy a bigger truck. The 8.0/8.4 rear end has proven surprisingly durable, I have to say. Understanding it's limitations and using a little care should help it live a long life. To be fair we are loading these trucks pretty good with all the armor and equipment.

 

[mvbeggs]

My stock gas mileage was 18 MPG. That was stock gears and close to the stock 4,000 weight. Now I'm getting 16 running empty with 1,000lbs additional weight. Add the trailer and gear and I'm down to about 13 in the mountains, 14 over rolling terrain. ...

Most manufactures size the diff according to power output and expected load. Toyota got it right for the smaller engines, but when they went to the 4.0 they did not upgrade the diff along with it. ....

....I've heard of these diffs being burned up with supercharged 3.4 engines towing on grades. If I saw the need to supercharge mine, I would include the cost of a Dana 60. Honestly though, I think the 4.0 is a fabulous engine for these trucks. If I really needed more I would probably just buy a bigger truck....

Downhill,

Thanks so much for the straight forward answers. Your response has given me reason to pause. (manual-4.56 gears-armored-and skinny tires yields 13-14mpg pullng the trailer in the mountains...16mpg running empty) Maybe your suggestion of a larger vehicle should be considered...

When I started building the Jeep, I knew nothing of overlanding. I only knew that I was going to be in the back country, and on my own. I didn't want to be stranded, so I built a Jeep that is capable of going over very difficult obstacles without breaking anything. Well, mission accomplished...the only problem is that I have a very capable, 6,000+ lb, 11mpg, Jeep with about a 200 mile range. Too bad I didn't give more thought to range and gas mileage during that build. If realistically, a Taco build is to going to improve gas mileage from my current 11mpg to the 13-14mpg range, I probably need to keep looking for a setup that will get me into the 15-16mpg range.

Thanks for your unbiased, straight forward, comments. You gotta love the portal!

Hope to see you on the trail. A cold beer is in my cooler wating for you!:beer: Thanks again.

 

[steve103]

mvbeggs thanks i think i would like to look at the 410s any good starting point?

 

[steve103]

mvbeggs thanks i think i would like to look at the 410s any good starting point?

 

[downhill]

Downhill,

Thanks so much for the straight forward answers. Your response has given me reason to pause. (manual-4.56 gears-armored-and skinny tires yields 13-14mpg pullng the trailer in the mountains...16mpg running empty) Maybe your suggestion of a larger vehicle should be considered...

When I started building the Jeep, I knew nothing of overlanding. I only knew that I was going to be in the back country, and on my own. I didn't want to be stranded, so I built a Jeep that is capable of going over very difficult obstacles without breaking anything. Well, mission accomplished...the only problem is that I have a very capable, 6,000+ lb, 11mpg, Jeep with about a 200 mile range. Too bad I didn't give more thought to range and gas mileage during that build. If realistically, a Taco build is to going to improve gas mileage from my current 11mpg to the 13-14mpg range, I probably need to keep looking for a setup that will get me into the 15-16mpg range.

Thanks for your unbiased, straight forward, comments. You gotta love the portal!

Hope to see you on the trail. A cold beer is in my cooler wating for you!:beer: Thanks again.

No problem, glad I could help!

 

[mvbeggs]

Sourcing- Tacoma 4.10 Gears

mvbeggs thanks i think i would like to look at the 410s any good starting point?

Here's where I saw them:

http://www.nitro-gear.com/ring-pinions/

There are several parts that look like they will work:
TV6-411-NG TOY V6 4.11 R&P ALSO TACOMA & 4RUNNER W/LOCKER
T8S-410R-OE TOYOTA 8" CLAMSHELL 4.10 (OEM)(05+ TACO, FJC)


also saw this 4.30
TV6-430-NG TOY V6 4.30 R&P ALSO TACOMA & 4RUNNER W/LOCKER

Let us know if your verify that these WILL work in the '05 and newer Tacos.

 

[downhill]

You need to email them. The website is deceptive. I'm pretty sure they only offer those gears for the rear and not the front, making them unusable in 4x4 applications.

 

[mvbeggs]

Here's where I saw them: (Tacoma 4.10 R&P)

http://www.nitro-gear.com/ring-pinions/

There are several parts that look like they will work:
TV6-411-NG TOY V6 4.11 R&P ALSO TACOMA & 4RUNNER W/LOCKER
T8S-410R-OE TOYOTA 8" CLAMSHELL 4.10 (OEM)(05+ TACO, FJC)
.....

You need to email them. The website is deceptive. I'm pretty sure they only offer those gears for the rear and not the front, making them unusable in 4x4 applications.

Thanks Downhill. The link was from another discussion I was following. The extent of my due diligence was to click on the provided link to see the 4.10 listed. I didn't go any further with it.

Steve103, Please let us know if you verify the existence of the elusive Tacoma 4.10, front AND rear, ring and pinion sets.

 

[steve103]

thanks every one for all your imput. new to all this so all the information is almost overwhelming. i will up date as time goes by. still need to get tires and see what happens. the 410 approach sound like what i would be looking for, 456 might be to much. we will see.

 

[mvbeggs]

Pulled the trigger-

After giving it some thought, and more research, I traded the 08 Tundra (2wd) in on a 2012 Taco. (white, double cab, V6, TRD Off Road package) It should be in my hands this week.

The goal is to build a rig that will get 15-16mpg and able to tackle moderate trails. The approach will be to build in phases, and evaluate the gas mileage and performance after each mod. Planned mods: fiberglass bed topper, aluminum front bumper, winch, steel or aluminum rear bumper, sliders, suspension and tires (re-gearing if required).

Keep the posts flowing. I'm looking forward to learning more from everyone's mods and ideas.

Thanks for all the great input.

 

[1911]

thanks every one for all your imput. new to all this so all the information is almost overwhelming. i will up date as time goes by. still need to get tires and see what happens. the 410 approach sound like what i would be looking for, 456 might be to much. we will see.

From my experience (with other trucks, including the FJC but NOT the Tacoma), going from 3.73 to 4.10 is barely noticeable, only a 10-11% difference. A lot of money to re-gear, for that little of difference IMO.

 

[downhill]

After giving it some thought, and more research, I traded the 08 Tundra (2wd) in on a 2012 Taco. (white, double cab, V6, TRD Off Road package) It should be in my hands this week.

The goal is to build a rig that will get 15-16mpg and able to tackle moderate trails. The approach will be to build in phases, and evaluate the gas mileage and performance after each mod. Planned mods: fiberglass bed topper, aluminum front bumper, winch, steel or aluminum rear bumper, sliders, suspension and tires (re-gearing if required).

Keep the posts flowing. I'm looking forward to learning more from everyone's mods and ideas.

Thanks for all the great input.

Hey congratulations! stick or auto? My advice would be to keep it light. Aluminum everything. Skids expecially can add a ton of weight and steel isn't needed for what you're doing. I have a lear fiberglass topper on my truck. Very solid unit but heavy! Mine is around 300 pounds. It came on the truck but at some point I'll probably trade it out for aluminum. All that heavy stuff adds up FAST. Time to start a build thread.

 

[mvbeggs]

Hey congratulations! stick or auto? My advice would be to keep it light. Aluminum everything. Skids expecially can add a ton of weight and steel isn't needed for what you're doing. I have a lear fiberglass topper on my truck. Very solid unit but heavy! Mine is around 300 pounds. It came on the truck but at some point I'll probably trade it out for aluminum. All that heavy stuff adds up FAST. Time to start a build thread.

It's an auto. Manuals are slim to non-existent around here.

Know what you mean about the skids. The LoD slider's on the Jeep are heavy, but durable. I'm anticipating the biggest decisions on this build is going to be the weight vs strength issue. I'll be tracking the weight coming off vs what is going back on as well as the influence of the weight change on gas mileage.

I'm looking forward to the build.

Thanks again for the help.

 

[Andy@AAV]

The goal is to build a rig that will get 15-16mpg and able to tackle moderate trails.

This weekend I went to Mohave area with some friends. I only got 15.5 on the way out there, mostly uphill from San Clemente. After a day of wheeling on old mining roads, running the truck this morning for some heat, and 60 highway miles I was still in the mid 15's at the next fill up. After that, all highway on the 15 back home I'm just under 17. YMMV, but that's what this thread is about, right?