52" michelins.........hmmm......5.71 and leave it in low range permenantly
Tire sizes and gears.
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OK im jumpin in on this one cause i have 33's and 5.29 with the 22re/auto setup i never use overdrive except momentarily on the interstate goin down long hills.......so i usually run it in Drive on the highway i get 75 mph at about 5000rpm the truck loves this and the torque is right in the sweet spot(i can keep up with traffic!!).........my question is when i swap to the 5speed is first gear lower than in the auto and is 5th gear higher cause i would like to use all my gears
Your numerical data agrees with my experience: 28/29" tires + 4.10 axle OK; 31" tires + 4.10 axle lost power, 5th gear unusable, etc; 31" tires + 4.56 axle fine but actually geared slightly low, speedo reads about 8% higher than actual speed, but a little more "power" is nice.
52" michelins.........hmmm......5.71 and leave it in low range permenantly
Naa, all you have to do is this....
Toyota double d's ? (apperently the name for it)
Since 4th is a 1:1, ONLY running the back tranny in 4th would have NO effect on doubling/ reducing a ratio. That leaves 1-3 as a REduction, and 5th as an OD. Ratio x ratio, will give you the overall reduction.
you sure you got 5:29s?
Gear ratio:
(rpm x tire dia/ MPH x 336)
5,000 x 33 (165,000) / 75 x 336 (25,200)= 6,547 (6:54 gears)
MPH:
(RPM x tire dia / gear ratio x 336)
5,000 x 33 (165,000) / 5.29 x 336 (1,777.44) 92.83 MPH @ 5,000 rpms
RPM:
(MPH x ratio x 336 / tire dia)
75 x 5.29 x 336 (133,308) / 33 = 4,039 rpms @ 75mph
Tires, Gears, MPH and RPM Relationship Between
IF, my math is right....
I think there a 4:33s available to. That would get you back, closer to stock, but a darn expensive way to do it...and all for 31's
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Oh heck yeah...They often always are. That's why auto's have LOWER differential gears than MTs.
No, the RPM drop from 4th to 5th is 250rpms. On an AT, 3rd to OD is 500.
What you need (this is very unorthodox and JUST MO) is to convert the 2ndary hydro TC, to the gear driven one.
In an extreme lean the hydro will stop pulling (AryraAburmany(sp) has a video of it doing it.) And, since its hydro, it acts like a 2nd torque converter, and torque converters do what? Rob power...
If you wanted the AT, I'd go that route. But honestly, the 5 speed would prolly be cheaper and easier
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4.37's were available in earlier 4 speed 4wd trucks.
I did some searching on changing out the speedometer gear to correct the speedometer, and here is what I found.
There are 5 common gears. Almost all have 6 gears on the output shaft, and between 15-20 on the gear side (most are 18). When pulling out the speedometer gear, look at the bottom of the plastic gear to see which one you have.
6x16: Common in 2wd's
6x17: Harder to find in 2wd's
6x18: Common in 4wd's
6x19: Rare in 4wd's
6x20: Rare in 4wd's
The ratios are calculated very similar to a ring and pinion
6x16: 2.67:1
6x17: 2.83:1
6x18: 3:1
6x19: 3.167:1
6x20: 3.34:1
This means if you changed out you 6x18 gear for a 6x20 gear, your speedometer will spin 11% faster. (3.34/3=1.11). So if your speedometer reads 65mph when you are really traveling 72 or 73 mph, the 6x20 gear will fix the problem for you.
There are 5 common gears. Almost all have 6 gears on the output shaft, and between 15-20 on the gear side (most are 18). When pulling out the speedometer gear, look at the bottom of the plastic gear to see which one you have.
6x16: Common in 2wd's
6x17: Harder to find in 2wd's
6x18: Common in 4wd's
6x19: Rare in 4wd's
6x20: Rare in 4wd's
The ratios are calculated very similar to a ring and pinion
6x16: 2.67:1
6x17: 2.83:1
6x18: 3:1
6x19: 3.167:1
6x20: 3.34:1
This means if you changed out you 6x18 gear for a 6x20 gear, your speedometer will spin 11% faster. (3.34/3=1.11). So if your speedometer reads 65mph when you are really traveling 72 or 73 mph, the 6x20 gear will fix the problem for you.
I know 4:87's (factory in my T100) and the un-regearable 4:87's in the AT's are rare...
I'd start there...
Good stuff to know, GRM...
I'd start there...
Good stuff to know, GRM...
This is exactly the thread I have been hunting. I think my question is pretty much answered in the initial chart. But curious as to one thing. I have a 88 sr5 5 speed 4 runner that came stock with 225/75-15 ( 29ish) says the door sticker, and 4.10 gears ( spun the wheels and did the math) I had initially thought this was a larger tire offering for the year and model. A little research indicates only this factory option?
Because I scored donor rust bucket w a set of differentials that had 456 gears and an ARB rear locker already installed compressor switches and all, I went for it. So no need for ya shuuda run 5.71 done a straight axle swap and put on 37 Muds. It is what it is.
So as I want to reverse engineer looks like optimal the tire size ( for my needs ) is something 32 ish . This is also nice because its right about where I can keep the rig at stock ride height.
Jerod points out that stock tire size makes a difference and provides some math I'm not ready to do before coffee to compensate. What was different between two trucks with same gearing but factory different tire sizes? Just the speedometer gear?
I currently have some kevlar duratrac 265/75-16 (31.6 inch) seems like I'm in or near the sweet spot according to the chart, though I haven't done the math. In the rear they are a bit of a squeeze. I haven't run them aired down offroad but seem to not be any interference. They are on some newer stock alloy yota wheels that take away from its 80's charm.
My shift points seem awkward and it is a dog climbing at the rate of traffic from a slow down or stop. Does fine at freeway speeds otherwise.
Have a feeling those duratracs are heavy and wide and high rolling resistance for my near stock setup. Clutch doesn't seem happy in first from stop. for reverse I really have to keep rpms up ar it wants to stall. Once I do the math will probably switch to a skinnier all terrain of the "optimal size" Prob Bfg KO2 like there winter rating and have done me right on My 80 series.
I am very close to having this runner be where I want it a fun daily driver grocery getter that can get me to trials and be a very capable off road rig, Might do an OME 2" ifs lift one of these days.
There I go, I've been wordy. Any input appreciated.
The main question is the difference between two trucks (if any) with the same gearing but factory tire size difference Speedo "caibration" for sure. Something different about the trans?
Because I scored donor rust bucket w a set of differentials that had 456 gears and an ARB rear locker already installed compressor switches and all, I went for it. So no need for ya shuuda run 5.71 done a straight axle swap and put on 37 Muds. It is what it is.
So as I want to reverse engineer looks like optimal the tire size ( for my needs ) is something 32 ish . This is also nice because its right about where I can keep the rig at stock ride height.
Jerod points out that stock tire size makes a difference and provides some math I'm not ready to do before coffee to compensate. What was different between two trucks with same gearing but factory different tire sizes? Just the speedometer gear?
I currently have some kevlar duratrac 265/75-16 (31.6 inch) seems like I'm in or near the sweet spot according to the chart, though I haven't done the math. In the rear they are a bit of a squeeze. I haven't run them aired down offroad but seem to not be any interference. They are on some newer stock alloy yota wheels that take away from its 80's charm.
My shift points seem awkward and it is a dog climbing at the rate of traffic from a slow down or stop. Does fine at freeway speeds otherwise.
Have a feeling those duratracs are heavy and wide and high rolling resistance for my near stock setup. Clutch doesn't seem happy in first from stop. for reverse I really have to keep rpms up ar it wants to stall. Once I do the math will probably switch to a skinnier all terrain of the "optimal size" Prob Bfg KO2 like there winter rating and have done me right on My 80 series.
I am very close to having this runner be where I want it a fun daily driver grocery getter that can get me to trials and be a very capable off road rig, Might do an OME 2" ifs lift one of these days.
There I go, I've been wordy. Any input appreciated.
The main question is the difference between two trucks (if any) with the same gearing but factory tire size difference Speedo "caibration" for sure. Something different about the trans?
Looks like I have near factory 21.67 "travel" with my setup. Used the Waze app (likely more accurate than my stock speedo) and the speedo and gps readings were the same up to 65 MPH. didn't focus on rpms That'll be interesting. Little tuned 22re still not thrilled with the weight and rolling resistance of the more Mud than A/T Duratracs IMO. IH8MUD. Like the kevlar sidewalls and off road ability of them, but will probably go milder on this rig.
Ok, so here is the chart I made. As you can see the 28 inch tires with 4.10 gears have a travel of 21.67 inches per drive shaft rotation. You can cross reference tire size and gear ratio to see what your travel would be and then compare that travel to the stock figure. If it's more than stock you can be sure of less power on the road, if it's less than you'll have more power, but lower top speed.
If you want a figure of just how much difference there will be in a percent just divide the new travel by the stock 21.67. Say you want to get some 31 inch tires and stick with stock gears, you would divide 23.75 by 21.67 and get 1.095 so your speedometer and odometer will be over by just under 10% So 50 means 55, 100 is now 110 (That was a joke!)
***PLease note that tire size has little to do with the actual size of the tire once mounted on a rim, and that as a tire wears it gets shorter, so take that into consideration when reading this.***
So by the numbers the best gear tire set-ups close to stock for a truck that came with "28 inch" tires and 4.10 are:
Size/Gears
28-4.10
29-between 4.10 and 4.30
30-4.30
31-4.56
32-4.56
33-4.88
34-4.88
35-between 4.88 and 5.29
36-5.29
37-5.29
38-a little closer to 5.71 than 5.29
39-5.71
40-5.71
****If you have an auto tranny, or your truck came with a larger tire package, you will want to refigure your travel length by multiplying your tire height by 3.14159, and dividing that by your differential gear that came stock. Then you can compair your number to the chart.****
You will start to want lower than stock gearing with bigger heavier tires, but these combos are all within 3% of stock, so no exuses for speeding tickets!
Any more questions?
View attachment 162858
If i use 37' tires and 5.29 gears , is it possible to break other car components ? I mean , i know it is possible but if your setup is close to stock how possible is to break something? It should be harder to break something, right???
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Everything breaks. U-joints are designed to be the 'fuse' in a driveline because they are the cheapest/easiest part to replace. Hammer a couple of sockets and getting razzed by your trail buddies and you;ll be good to go in short order. I carry spares.
I know, im just asking if you are near to stock with that setup , then the possibilities to break something are the same as the possibilities to break something with 31x10.5 r15 and 4.11 gears , am i right?
2ndGenToyotaFan
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The taller the tire, the more leverage it has on the axle, diff, and drive-line. The more gearing you add to your truck (T-case and Diff gears) the more leverage it has on the tire. Regearing for the larger tire alone will not change the second part of that equation, but the larger tire will make it easier to break things. With that said, if you don't hammer on your truck it'll last a long time like that, lots of Toys running 37's. 
Ok, rebuilt/ desmogged 2f, Fj 60, H55H on BFG AT 33x10.5x15, and about a 4” lift, 38g tank. 6200 pounds full loaded. Currently getting between 12-14mpg on mostly flat highway driving.
No idea what gears I have in it as I’m the 3rd owner, but she’s a pig on those long up hill SOCAL highway climbs. Hell any hill for that matter. Was thinking of 4.56.
What if I put 35x16 on her?
Thanks
Chris
No idea what gears I have in it as I’m the 3rd owner, but she’s a pig on those long up hill SOCAL highway climbs. Hell any hill for that matter. Was thinking of 4.56.
What if I put 35x16 on her?
Thanks
Chris
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2ndGenToyotaFan
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First I would recommend finding out what you have in it now. Put a chalk mark on the tire and ground, and on the pinion flange and body of the differential. Jack up one tire and rotate the tire exactly 2 rotations and count the number of rotations you see at the pinion flange. It should be easy to tell between 3.7, 4.1, 4.56 etc. (If you do this on the rear axle, be sure to chock the front tires, and if you do it on the front be sure to set the parking brake and to lock the hubs or it wont work)
Gearing down is going to cut you're top speed, and eat up some of your mileage. With 33's I would recommend 4.88's personally.
Gearing down is going to cut you're top speed, and eat up some of your mileage. With 33's I would recommend 4.88's personally.
Um, I'm going to suggest posting this in the 60-section. A search over there should give you what it came with from the factory (4.11?). They can also give you more real world suggestions. I think 99% of your issue will be your KA smog junk. Don't be surprised if they suggest a V8.
That said ... I have a FJ40 which is much lighter. I run 4.11, H55F, 35"s, but have the Mark's TC gears with the 10% under drive. It's perfect. Oh, engine is a desmogged 3FE stroker (2FE), so I have a bit more engine.
That said ... I have a FJ40 which is much lighter. I run 4.11, H55F, 35"s, but have the Mark's TC gears with the 10% under drive. It's perfect. Oh, engine is a desmogged 3FE stroker (2FE), so I have a bit more engine.
Lots of guys with the manual 60's think 4.11's are fine for 33's, but as heavy as that truck is loaded-and man, that's a load-I would go 4.56. Maybe even 4.88 if you're thinking about 35's-which I wouldn't do. They'd likely rub, in addition to making it even more difficult to stop, more weight, more wear, etc.
