How do the final drive ratios of the G57 5-speed and G40 4-speed compare? I'm having trouble finding reliable info on this.

If a 5-speed can be sourced cheap, is it worth the trouble of swapping it into a pickup originally equipped with the G40? Are the physical dimensions of each transmission the same? Mounting points, etc? Would swapping trannies also require different brackets, driveshaft, etc?

 

5th gear is overdriven "overdrive"... meaning lower rpms on the highway.

All 4th gears are a 1:1.

A 5 speed swap is good if you drive over 55mph on a regular basis and want to save some gas.

If you get a 5speed from another truck with a 22r/e it should swap over just fine.

 

except toyota changed diffs for the 4 speeds so 4th is usually where 5th is on the 5 speeds overall. (same cruising RPM) So you end up with similar 1st and similar top gear, the 5 speeds just have an extra gear between.

The meat of the info I posted on ToyotaNation:

Things that WILL happen (I swapped a 3.07 8" rear end (std for 4 sp) into my 5 speed 91):
-your speedometer will be around 15-18% off unless you swap the speedo gears from your 4 speed to the 5 speed
-the truck will be even more slow. the 5 speed has slightly taller 1-3 4th is the same, and 5th is even higher, like 6th on a T56: absolutely no acceleration. If you line them up it's a little like this (if you factor in the different rear ends):
1.....2.....3.....4__________(stock 4 speed/3.07)
.1...2...3...4...5__________(stock 5 speed/3.58)
...1....2....3....4...5_______(5 speed w 3.07)
.....1...2...3...4....5......6__(LT1 T56/3.42)

I'm not saying don't, just saying what will happen so you can decide. I don't mind the ratios but I drive it like a granny (usually) anyway.

Manual transmissions: 4-speed vs 5-speed - Toyota Nation Forum : Toyota Car and Truck Forums

and to your question, yes the 5 speed was for closer ratios but the same overall spread for drivability/economy. using a OD transmission with the 4 speed 3.08 axle will decrease off-the-line acceleration (though once you're moving, the gears are slightly closer) but improve cruising mileage. unfortunately, the 22RE has barely enough oomph at that ratio (3.08/OD) stock so it's working really hard to move the truck so the mileage benefit isn't that great. I went from mid-20s peak highway mpg to mid-upper 20s. not enough to pay off before the truck rusts out. On the other hand, I do have an extra 7M that needs minor work that would have plenty of punch at that rpm.

 

Eh, it doesn't sound like swapping one for the other is worth the trouble, then. There's nothing mechanically wrong with my current 4-speed, so I suppose I'll just leave it be.

 

I see what you're saying...

I have a 4-speed rear end and a 5-speed. I know the 22r isn't made for power, so no disappointmen here.

I haven't experienced the 4-speed first hand, so I don't know, but I'm turning around 2500rpm at 70mph (gps). The speedo says I'm doing 60mph....

 

My truck came with a 4 speed and a 3.42 rear axle ratio. When I went to a w58 the cruising rpm dropped alot.

Granted my truck has a little more oomph than a stocker, it was a good thing to swap.

I'd suggest swapping in a 5 speed regardless. Iirc the w58s have a taller 5th gear than the w55-56 whatever truck 5 speeds.

 

I say if you plan on running a 5 speed swap out your third member from the 5 speed doner truck.It will be worth it.Here's how you identify the gear ratiohttp://www.brian894x4.com/Gearratiosanddiffs.html

 

Gearratiosanddiffs

 

A 5 speed swap is totally worth it. Very straightforward. When I got my 89 pickup I had no idea it was a 4 speed because the bottom end was wiped out due to the chain guide issue. After I rebuilt the engine and got it running, I went to put it in 5th and...brick wall. The only thing you need to get is a rear mount from a 5 speed truck. If I remember right the mount location for a 5 speed is shorter. The driveshafts are the same. Easy swap. Do it. I still have the factory 3.73 rear end in mine. I get about 24 mpg combined city/highway. That includes a lot of time spend in Atlanta metro area traffic