atcfixer

iTrader: (1)

For the transmission reference, Marlin Crawler is pretty good resource.

https://www.marlincrawler.com/transm...complete/r150f

Scroll down to the Toyota TransmissionApplication Table

The "old style" is 88-95 pickup (pre tacoma)/T100/4Runner, and the "newer style" is 95-05 tacoma/t100/4runner

I don't know what 2006 and newer transmission is, I suspect that's when they switched from the 5VZ to the 4.0L.

As for the bigger tires/off roading, I'd suggest have a truck for off roading, and a truck for mpg, on road hauling etc.

space-junk

iTrader: (1)

a dual trans setup isnt much longer than a dual case setup FWIW.

skullhead690

this is a really good idea, and certainly easier than doing what im thinking about. But I don't like the output ratios of the r156/larger tires. That would slow things down off the line. And I like the way it feels right now. As well as the intent is to not be stuck with one or the other option. I would like the choice and versatility. I understand the concept of choice does come with its challenges. And that's why I came here, I want to hash out those challenges. If I need to mold and cast a new gear set maybe I should do some research on how much that would cost. Ill think about producing a prototype to bench test. Keep in mind guys, im not expecting any of this to be easy. And for those of you that think im trying to reinvent the wheel, we wouldnt have vehicles the way they are today if someone didn't try and reinvent the wheel.

atcfixer

iTrader: (1)

I suspect creating your own gear set might be fairly expensive... HOWEVER... there are aftermarket companies already making aftermarket gears. Contacting them might be the best option to see if they would be willing to work with you and see how much the production costs would be. You might have to do a group buy to meet some minimum quantity. Just guessing, but I'd think $5-10k would be the price range you'd have to spend to get a set made with or without "extras" to sell I'm unsure. Tooling up is the most expensive part, making more after being tooled up is just material cost and machining costs.

Just to compare, look at how much an aftermarket cam is vs a custom (say reverse grind) cam is. That's kind of a one off production, but they are tooled up for accepting requests like that.

dropzone

iTrader: (6)

it seems to me that if it were a technically viable, marketable option a company like Marlin, Advance Adapters, Trail Gear etc would have already tried it since it would be an awesome, deal. Re-gear one thing (the T/C) versus re-gearing two differentials

millball

For sure.

Several folks pointed this out on page one of this thread.

Yotard

At the end of the day what kind of mileage would you actually get? A lot of your mileage is the fact that your truck is as aerodynamic as a brick and it gets exponentially harder to push air the faster you go. You lug you lose efficiency and if you are over Reving you are losing efficiency. If you have a stock truck with stock gear ratio chances are you aren't going to improve the efficiency. The Japanese engineers were pretty good at optimizing for efficiency. If you change tire size or engine then gear ratio comes back into play otherwise I bet you can spend a couple thousand dollars and get next to no change in mpg.

skullhead690

Thanks for your input guys, and like I had said previously if its not viable I can totally stomach that. Im fairly technically proficient so just hearing its not possible, "because I said so" doesn't work for me. Thanks to those who have given me facts and technical answers I agree that its not a viable option.

[QUOTE=millball;52351812
I think if it was possible to provide overdrive by regearing a t-case, someone would offer kits for sale.
[/QUOTE]

This doesn't tell me why its not possible, just that its not. I was looking for why.

Thanks to rattlewagon for showing me that the gearing and shafts are fused. if I would've known that sooner than I would've understood. I wasn't here to know who is smarter, I wanted to find out why it was/wasn't possible, and thankfully I had some people that could deal with this in a mature fashion and give me fact as opposed to conjecture.

Also thanks to atcfixer for humoring my brainstorming. but sadly after doing some research on fairy/toro overdrive units iv found that the compact design of gearing just isn't sturdy enough to handle the torque, like you had mentioned. The gearing seemed to be a very big weakness in those units and also why they stopped production. So like I had said previously ill probably begin some research into dual transmission to see what I can find.

atcfixer

iTrader: (1)

Driving habits are one of the largest factors for MPG, but if he did regear higher there should be an MPG increase up to some point that the engine is lugging and MPG drops off the charts. Toyota engineered a truck for work, so they are geared lower than "ideal" for MPG. Their engines/transmissions etc is quite efficient, so they get pretty good mpg vs some other pickup makers.

I have a 86 22r pickup that has gotten 30mpg driving it easy, but it's high geared, 3.58:1 and I put oversized tires on it ~7% larger. Carb float is too high (floods at low throttle) and one caliper is hanging after braking, so I know it could get better. I'm a pretty efficient driver though MPG wise. My truck is 2wd, so a little less drag, it is lower to the ground with helps areo a lot, and the truck is quite light vs a 4wd which helps takeoff efficiency which can be countered with efficient braking (aka ecomodder coined it driving without brakes, you coast down enough to not need brakes to corner etc).

skullhead690

Like I had said previously I drive extremely MPG conscious. I usually shift earlier than necessary and I barely use my brakes. My other commuter is a motorcycle and downshifting is recommended as opposed to braking on two wheels and iv adapted this to my automobile driving as well. Aero is another reason I don't want to make my tires any bigger. My truck has a body lift plus larger tires so its already fairly tall. Any taller and I would lose even more MPG, kind of counter productive.

atcfixer

iTrader: (1)

Most efficient coast down is actually engine off neutral costing (super extreme), next is neutral with engine idling, then after that it's engine braking in gear with fuel injector cut off feature of modern machines (this is best if you need to slow down faster than neutral costing like a light turned red and neutral costing would let you travel too far).

Engine off is a touchy subject, wheel lock, vacuum assist braking, no power steering all are lost to some extent, it's not really advisable for most people and some states it might be illegal. The injector cut off feature is basically the same as leaving the truck in gear (manual) and turning the key off with the exception of possible steering wheel lock (the Toyota's I've worked with requires key removed before wheel will lock), of course it's an automated feature.

There are some cars that will turn the engine off when you stop and restart automatically when you give it gas purely to save the fuel used to idle.

Here is a good collection ecomodder has on tips to save fuel. Some are simple that everyone should do, while others are more on the extreme side of things like engine off coasting.

http://ecomodder.com/forum/EM-hyperm...ecodriving.php

Co_94_PU

iTrader: (-1)

yes, reversing these will give it a big overdrive. There a problem however. If you put number four on the bottom it's not going to fit in the case. The forward gear is smaller so you will need two sets of the first gear set to fit the case dimensions. That will get passed the first interference.

Second interference will be the central housing, some of the stiffener ribs might need milled down.

looks like a third with the idler shaft bearing, which needs recessed more.

skullhead690

I think the intent has been lost along the way. These would be beneficial in a scenario where i would be stopping. My intent was for this to be useful during highway driving. When the vehicle will be in constant velocity. and to answer some previously mentioned questions my vehicle did start with the smaller tire set. Here is the door side sticker to verify this.

atcfixer

iTrader: (1)

It has been proven that the door sticker isn't as accurate as you'd like it to be. A vin check for the towing package and what gear ratio the axle is would be much more accurate. G294 axle code suggests (not 100% accurate either) that it has 8in ring gear (V6 3rd member), 4.10:1 gear ratio with 4 pinion (also V6 typically). You can also climb under and look at the ribs along the side of the 3rd member. If I remember correctly 4 ribs = V6 housing while the 22re would have the 3 ribbed in most cases except 1 tons and the turbo trucks.

Constant speed mpg tips would be the ones relating to hills (slow down going up, speed up going down which lets gravity recoup some of the cost of going up), and high speed (say 55mph+) areo is HUGE and gearing is pretty big too. Slowing down from 70mph to 60mph can save you 5-10% in fuel. There is also a term they coined with a new style of cruise control (or manually) that's called driving under load from memory. The idea is to keep a steady gas peddle and let your speed go up/down with the terrain.

If you really want good mpg, I'd say to put on a belly pan on the 4 runner to smooth the underbelly areo, remove roof racks if you have them and never use them (seal the bolt holes if needed), you could do some front end mods, but generally it makes the machine look ugly. It's function over looks when it goes to the extremes.

This is more or less the most ideal areo car (there are better shapes, but this one takes an existing shape and deals with it's flaws areo wise). http://www.aerocivic.com/

Some fun specs out of their little 4 cyl (lean burn) engine. Also shows the areo effect fairly well, faster = costs more fuel. For the "general" car/truck, the point where it starts to scale up fast is much lower speeds.

• 95 mpg (US) at 65 mph
  (2.5 L/100 km at 105 km/h ... 40.4 km/L ... 114 mpg (Imp.))
• 85 mpg (US) at 70 mph
  (2.8 L/100 km at 113 km/h ... 36.1 km/L ... 102.1 mpg (Imp.))
• 65 mpg (US) at 80 mph
  (3.6 L/100 km at 129 km/h ... 27.6 km/L ... 78.1 mpg (Imp.))
• 50 mpg (US) at 90 mph
  (4.7 L/100 km at 145 km/h ... 21.3 km/L ... 60.1 mpg (Imp.))

skullhead690

I know, im asking for a lot of help but im stumped on this one. Im interested in the dual tranny set up since i seem to be debunked on the t-case idea. i went on pirate4x4 since that seems to be the only place with any info in it and found a member who seems to be the most recent with the ability/desire to make an adapter. only problem is when i try and make an account to communicate with this member the site crashes and wont let me register. Anybody able to get me in contact with the member freeclimber00? or in contact with someone so i can get registered?

space-junk

iTrader: (1)

Contact an administrator over there. Just be aware, those guys aren't always kind to people asking questions they deem frivolous.
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