Tire Size and Gear Ratio

[ajordan1975]

Do the gears. Buy 35's. Sell 33's to recoup some of the cost of said 35's

 

[ajordan1975]

35s and 488 is great. 37s and 537 is supreme on and offroad.

i'm over-geared w/ 5.29's and 37's

 

[Broski]

Just go 5.29s so you can run 37s it's the natural progression
Don’t waste time and money on 35

 

[Rudster]

Stock gears 35 and at 7000lbs Ill go up any US interstate hill at 65. Flame On!

I run the same setup with the same success.

 

[SNLC]

Stock gears 35 and at 7000lbs Ill go up any US interstate hill at 65. Flame On!

Same but mine will do better than that, I just got to hold 2nd and 4k rpms.



Cheers

 

[baldilocks]

no. I have 4.88 and underdrive TC high range, i think that puts me close to 5.37?

I think it’s actually more like 5.15:1.

 

[Squeegee]

I run the same setup with the same success.

Mmmm you must not travel in Montanawhen I had that set up, I’d have to go up some hills going 45 screaming in 2nd.

 

[baldilocks]

I have 1991 HDJ 4.2 12V turbo with 35" tire and 3.727 ratio. I tought it is 4.10. But axle code K305 said it is 3.727. With 5 speed manual H151F. Now I am thinking add ARB front&rear air lockers RD132 and RD142 and pair it with Yukon 4.88. I am not sure is it good idea and is it even physically possible to connect those two. Or I should regear to 4.56... dilema... I would like to gain torque but not add to much rpm. I am not into top speed... It is not my dd, I use it for trips. In my country is a lot of hills and ups and downs

View attachment 3292870

You will probably find more pertinent information over in the diesel section. Your engine power curve and rpm for efficiency is different than the gassers especially the 1fz.

 

[Darije]

You will probably find more pertinent information over in the diesel section. Your engine power curve and rpm for efficiency is different than the gassers especially the 1fz.

Oh, thanks. I will take a look. If you have more info fell free to let me know.

 

[baldilocks]

Oh, thanks. I will take a look. If you have more info fell free to let me know.

According to the tag in the door jam, what was the original tire size?

 

[Darije]

According to the tag in the door jam, what was the original tire size?

265/75/16. I have to check door tag one more time

 

[baldilocks]

265/75/16. I have to check door tag one more time

A 35” tire is only 13% taller than the stock tires. That means that, mathematically, you need 4.21:1 gear ratio. 4.30:1 would be the closest possible ratio that Toyota used. I wouldn’t go lower than 4.56:1 due to the 1hd-t torque peaking at 1400 rpm and HP peaking at 3600 rpm. You could easily end up outside that engines power curve. Your 1hd-t powered Cruiser got 3.73 gears instead of 4.10’s for this reason. I base my recommendation of 4.30-4.56 gears on the fact that you said you do drive improved roads in your country therefor I assume your intention is to restore stock like drive ability.

 

[Marco Lau]

38 and 39s are the new 37s and 42s are the new 40s.....V8 swap is inevitable.

Mmmm you must not travel in Montanawhen I had that set up, I’d have to go up some hills going 45 screaming in 2nd.

Altitude plays a big role too, what's the elevation up in Montana?

 

[Darije]

A 35” tire is only 13% taller than the stock tires. That means that, mathematically, you need 4.21:1 gear ratio. 4.30:1 would be the closest possible ratio that Toyota used. I wouldn’t go lower than 4.56:1 due to the 1hd-t torque peaking at 1400 rpm and HP peaking at 3600 rpm. You could easily end up outside that engines power curve. Your 1hd-t powered Cruiser got 3.73 gears instead of 4.10’s for this reason. I base my recommendation of 4.30-4.56 gears on the fact that you said you do drive improved roads in your country therefor I assume your intention is to restore stock like drive ability.

Thanks for reply. Yes, I would like to restore oem performance. With this tire/gear set I don't have power, from dead stop, to start moving the car in steep hill/road in 1st gear High. Even in some steep car garages. If I have small momentum of moving and turbo kick than it is ok. Otherwise I have to put in Low gears. I didn't have that kind of 'problem' before 35"

 

[baldilocks]

Thanks for reply. Yes, I would like to restore oem performance. With this tire/gear set I don't have power, from dead stop, to start moving the car in steep hill/road in 1st gear High. Even in some steep car garages. If I have small momentum of moving and turbo kick than it is ok. Otherwise I have to put in Low gears. I didn't have that kind of 'problem' before 35"

View attachment 3296049

Having problems to get rolling in a parking garage with stock tires could indicate an issue with the tuning of your engine.

 

[Darije]

Having problems to get rolling in a parking garage with stock tires could indicate an issue with the tuning of your engine.

I didn't have that problem with stock tire size. I got it after I put 35".

 

[Broski]

Really nice Rig !!!

 

[Marco Lau]

I didn't have that problem with stock tire size. I got it after I put 35".

That makes absolutely zero sense....

 

[Squeegee]

38 and 39s are the new 37s and 42s are the new 40s.....V8 swap is inevitable.

Altitude plays a big role too, what's the elevation up in Montana?

Tall

 

[Darije]

That makes absolutely zero sense....

Probably, but it is my reality... And I don't like it. What else can be an issue? Car drives good at road, engine and turbo are fine. I ordered new clutch. I've been waiting for install