Gear Swap
#1
Gear Swap
Interested in swapping from my 4.56 gears to something larger. I'm running 32" tires on a 3zve with an AT in a 1994 pickup, so under-performing is an under-statement. It is brutal on the mpg's. With the stock 225 75/R15's, it runs great and gets over 16 mpg and the speedometer is dead on with the gps speed. As is, no power and gets about 8 mpg. The theoretical gear size that would provide the same performance as stock with the 32" tires would be a 5.16, which obviously is not available.
2 Questions for those knowledgeable on the subject: 1. Which gear would be best for this setup, the 4.88 or 5.29? (5.16 is about right in the middle of the two gears) I do about 50/50 highway and offroad based on running time, so more highway mileage than offroad; and 2. This is probably outside of my experience level and time availability, so what could I expect to pay a shop for this swap?
Thanks,
2 Questions for those knowledgeable on the subject: 1. Which gear would be best for this setup, the 4.88 or 5.29? (5.16 is about right in the middle of the two gears) I do about 50/50 highway and offroad based on running time, so more highway mileage than offroad; and 2. This is probably outside of my experience level and time availability, so what could I expect to pay a shop for this swap?
Thanks,
#2
Registered User
If a shop provides all the parts and R&Rs the 3rds as well as does the gear setting, I'd think you are looking at $2000 give or take a few hundred.
I'm so glad that I can do this kind of work myself.
As to the best gear ratio, I don't know. Hard to believe that mileage could go from 16 to 8 with just that tire change. Pretty extreme.
I run 4.56s on very near a 32 inch tire on my manual tranny 3vz Runner and I get 17mpg under the worst conditions and near 20mpg highway if I hold to 60mph.
I'm so glad that I can do this kind of work myself.
As to the best gear ratio, I don't know. Hard to believe that mileage could go from 16 to 8 with just that tire change. Pretty extreme.
I run 4.56s on very near a 32 inch tire on my manual tranny 3vz Runner and I get 17mpg under the worst conditions and near 20mpg highway if I hold to 60mph.
Last edited by millball; 09-25-2018 at 06:45 AM.
#3
If a shop provides all the parts and R&Rs the 3rds as well as does the gear setting, I'd think you are looking at $2000 give or take a couple hundred.
I'm so glad that I can do this kind of work myself.
As to the best gear ratio, I don't know. Hard to believe that mileage could go from 16 to 8 with just that tire change. Pretty extreme.
I run 4.56s on very near a 32 inch tire on my manual tranny 3vz Runner and I get 17mpg under the worst conditions and near 20mpg highway if I hold to 60mph.
I'm so glad that I can do this kind of work myself.
As to the best gear ratio, I don't know. Hard to believe that mileage could go from 16 to 8 with just that tire change. Pretty extreme.
I run 4.56s on very near a 32 inch tire on my manual tranny 3vz Runner and I get 17mpg under the worst conditions and near 20mpg highway if I hold to 60mph.
I don't know, maybe I should just sell the truck to someone interested in keeping the stock size tires, and buy myself one with the manual tranny. Other than this problem, the truck is in great shape (not the body necessarily, but who cares about that). The engine was completely rebuilt, bearings, steering, suspension all tight, awesome ac, even the dang cruise control and power windows still work.
#4
Registered User
I thought that most automatic V6 4Runners came with 4.88s from factory, maybe I'm wrong there. Can you tell us your axle code just to verify? G144 is 4.88, I don't know what 4.56 is but google can tell us. I'd get at least 4.88s if you don't already have them.
#5
Form the door, the axle code is G254, Transmission code is A340H
#6
Registered User
Ok, G254 is 4.56 according to google, so I guess your truck came that way. Your factory tire size is roughly 28" tire, other reading I did suggest that trucks with 31" tires, automatic, V6, and possibly tow package got the 4.88s. One option you have is to find factory 4.88s from junkyard and swap those complete 3rds in, that would be probably the cheapest option, however 4.88 thirds would be used, of questionable condition, and are unique ring gears with an offset in the housing that cannot be re-geared if that matters to you. If you are going to have someone set you up with different gears, check ZUK at www.gearinstalls.com, he is the best.
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elaketiger (09-25-2018)
#7
seems to me that you have another issue that you need to look into besides gears.
I am getting 14-15 combined MPG with 35's and 5.29 gears, seems hard to believe that 32" tires would have impacted your mpg that much.
are you measuring your distance traveled with a GPS so you know for sure that you are calculating gas mileage correctly?
I am getting 14-15 combined MPG with 35's and 5.29 gears, seems hard to believe that 32" tires would have impacted your mpg that much.
are you measuring your distance traveled with a GPS so you know for sure that you are calculating gas mileage correctly?
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#8
seems to me that you have another issue that you need to look into besides gears.
I am getting 14-15 combined MPG with 35's and 5.29 gears, seems hard to believe that 32" tires would have impacted your mpg that much.
are you measuring your distance traveled with a GPS so you know for sure that you are calculating gas mileage correctly?
I am getting 14-15 combined MPG with 35's and 5.29 gears, seems hard to believe that 32" tires would have impacted your mpg that much.
are you measuring your distance traveled with a GPS so you know for sure that you are calculating gas mileage correctly?
#10
I have 4.56 gears and been thinking to swap them for 4.88 or larger as well. But after some research and labor quotes, I'm considering that the cost is not much cheaper than installing a MC dual transfer case. Wouldn't that give way more lower gearing options with 4.56 than swapping the actual gears?
#11
Registered User
I have 4.56 gears and been thinking to swap them for 4.88 or larger as well. But after some research and labor quotes, I'm considering that the cost is not much cheaper than installing a MC dual transfer case. Wouldn't that give way more lower gearing options with 4.56 than swapping the actual gears?
#12
True. I'm after more low end torque. In Hi-2wd only way to change rpm would be larger gears.
OP, 32" with 4.56 gears should only affect rpm by -3% . If you are trying to fix the low mpg, I don't think that's where the problem is. Something else is quite off in the engine.
https://www.roundforge.com/articles/...t-your-toyota/
OP, 32" with 4.56 gears should only affect rpm by -3% . If you are trying to fix the low mpg, I don't think that's where the problem is. Something else is quite off in the engine.
https://www.roundforge.com/articles/...t-your-toyota/
#15
Registered User
i had an 88 runner for several years with 4.30 gears and 35s and although it was way underpowered i got much better mileage than you.. id say you have another issue as well. i had the 3.0 with automatic as well. i did have some lce headers on it but that wouldn't make the changes your noticing.
#17
i had an 88 runner for several years with 4.30 gears and 35s and although it was way underpowered i got much better mileage than you.. id say you have another issue as well. i had the 3.0 with automatic as well. i did have some lce headers on it but that wouldn't make the changes your noticing.
#20
Registered User
iTrader: (1)
You have pulled them or are just looking for the engine light? Often the ECU will store a code but you wont get a flash.
If you tried to pull them and they aren't any then I would start looking for vacuum leaks. Carb cleaner or starter fluid sprayed around vacuum lines while running. If the engine races at all you found one.
What is your timing set at?
Take a noid light and make sure all injectors are firing. Pull plug wires one at a time while running and see if you get one that does not affect it running.
What about fuel filter?
What do your plugs look like? Post pictures.
If you tried to pull them and they aren't any then I would start looking for vacuum leaks. Carb cleaner or starter fluid sprayed around vacuum lines while running. If the engine races at all you found one.
What is your timing set at?
Take a noid light and make sure all injectors are firing. Pull plug wires one at a time while running and see if you get one that does not affect it running.
What about fuel filter?
What do your plugs look like? Post pictures.