need Pro's and Con's for gear upsize (1 Viewer)

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Friends and members need some input on diff gear ratio, currently OEM set of 1986 model HJ60 which i suppose runs on 3.78:1 correct me if i'm wrong have installed 35" maxxis tires on 15" rims. I'm not into hardcore off-roading and will use the truck as a expedition vehicle with some camping gears and which will involve hill drives also planing a trip to Leh and Laddakh northern part of India which is one of the highest drive-able mountain peak which stands at 13000 ft from sea level. now want help in deciding differential gear size.
1) do i need to upgrade?
2) if yes what would be the ideal upgrade?
please explain in lay man terms as my IQ is bit low:bang::bang::steer::steer:
 
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What engine is in your HJ60?

It sounds like you are trying to relate the tire size (height) and diff gears to the optimal 'cruising' rpms for you engine.

So if you know the RPM for your engine that gives you peak torque/power, then you can calculate the gearing and tire size so that you fit within that RPM range...

This fellow was hunting after the same thing...might send him a PM to see how he finally got where he wanted to be:

https://forum.ih8mud.com/threads/hj...-too-much-info-out-there.802686/#post-9159304
 
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Do you have a turbo on this engine? If not, you are going to be underpowered. 5 Spd transmission?
You would be better served to run 33" tires. So I would recommend either a turbo or 4:11 gears, or better yet, both.

BTW, I was there 2 yrs ago, and flew survey over Leh / Manali and Khardungla Pass. I am in the process of planning to
return and do this same drive, continuing up to Srinagar, then back to Gurgoan with a friend.
 
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Cruiserpilot yes I have installed CT26 turbo with inter cooler setup, already bought 35" so can i say that i'm safe to pull on such heights? let me know when you plan for the Leh trip see if i can join also.
 
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I have 12ht, and run 3.70 gears on 34" ( 285/75R17 ) tires. I call it compromise to highway driving and fuel economy.
Proper trail gears would be 4:11, or in between with 4:56 gears. But if I remember, average speed is less than 80 kph
my opinion is you'll be ok.
I looked and didn't even see a Land Cruiser the whole time in India. Quite rare there unfortunately. Could you post a pic?
 

Tapage

Club 4X4 Panamá
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a plain CT26 ( there are 3 versions ) coming from 1HD-T will be to big for your 2H .. therefore .. will not make low end boost to compensate taller gears ( or bigger tires ) so ..

35" with plain 2H = 4.56

35" with healthy 2H + turbo = 4.11

trust me on this .. I've been all over gears and tires combinations ..
 
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I agree with Tapage. Either 4.11 or 4.56 are going to be your best option. On top of what Tapage said if most of the trip is up and down a lot of hills then I would lean towards the 4.56's and if it is mostly flat highway driving then the 4.11's.
 
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Picture 030.jpg
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The first pict is how i acquired her and after a year this how she stands today, full ironman kit, turbo intercooler setup, complete body work and mechanical s completed pending to start of with painting.
 

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