4.56 and 33" Tires?

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NMC_EXP

NMC_EXP

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Feb 4, 2006
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Location
Raton, New Mexico
I have an '85 FJ60, 2F engine w/good compression, 4 spd, desmogged, engine runs very well. The 60 has all the add-ons: suspension, front bumper w/winch, rear bumper with swingouts, full size Wilderness roof rack. Tires are 33x10.5R15. The PO swapped factory gears for 4.10s which get it close to factory gearing.

With the add-ons and the gear I normally carry the 60 weighs 5,320 LB. That is no people and no camping gear, and no food & water.

Driving style is laid back, as in "go as slow as you can and as fast as you must". No rock crawling.

I'm in Colorado. To me it seems like lower gears would help. I'm thinking 4.56. I plan to stay with 33" tires

Any of you running a 2F with 33" tires and 4.46 gears in the mountains? Tell me the good and bad of that setup.

Thanks

Jim
 
33s with 4:56 is the same as running 27" tires with the stock 3:70 gears. Fine in the hills and off road, not fun over 60 mph. Stock tires were 28".

Reference rpms below are at 65 mph.
image.webp
 
I just got a set of 4:56 gears, haven't installed them yet but plan to do it soon. Will let you know if I like them. We don't have any big mountains here in North Alabama, but we do have some pretty good hills and the 33x12.50X15 tires I have are too much for the 3:73s in the hills.

I use mine at the off road parks around here for some moderate trails and am happy to go 60 or 65 mph for a few hundred miles or so to get to the parks and other places we ride. My goal was to have something pretty low geared but still be able to drive to the trails and back and not get the bird too many times. If had to do longer trips I probably would want a little higher gear.
 
I used to have Tencha back in the day wtih 4.56 and 33" tires .. with a 4speed that's not a combo that I would like .. given your conditions I would do only if you see a H55F in your north ..
 
The chart has good info - thanks.

With the current setup, I rarely run over 60 mph anyway.
 
Tapage said:
I used to have Tencha back in the day wtih 4.56 and 33" tires .. with a 4speed that's not a combo that I would like .. given your conditions I would do only if you see a H55F in your north ..
Click to expand...

Is the H55 1st gear lower than 1st in the 4 spd?
 
Output Shaft said:
Yes. Here's a chart

Transmission Ratio Information
Click to expand...

Thanks for the chart. Some of the info does not agree with what I thought I knew, and that ain't saying much:

FJ40 - 6 CYL PETROL (2F) - 4 SPEED H42 TRANSMISSION -16T SPLINE ONE PIECE TRANSFER CASE - 1st gear = 3.555:1
FJ60 - 6 CYL PETROL (2F) - 4 SPEED H42 TRANSMISSION - 19T SPLINE TWO PIECE TRANSFER CASE - 1st gear = 4.843:1
FJ60 - 6 CYL PETROL (3F) - 5 SPEED H55F TRANSMISSION -19T SPLINE TWO PIECE TRANSFER CASE - 1st gear = 4.843:1

1) It shows the H42 in a 40 has a higher 1st gear than the H42 in the 60.

2) There are both 16T and 19T version of the H42 transmission.

3) The 1st gear ratio for the FJ60 H42 and the FJ60 H55F are the same.

Is that info accurate?
 
No. That one has errors in it.
The one at SOR looks right.
Transmission Gear Ratio FAQ

There are lots of references if you google it.

I used to have a link somewhere of a good table of all the transmissions. Musta deleted it.

Bottom line:
The 5 speed with 31" tires in first gear feels like the H42 with 225/75R15 stock tires. 2nd gear is low enough to roll through stop signs very slowly without shifting into 1st with 31" tires. 3rd gear is million miles away from 2nd and the gap is too far which really sucks. 3rd to 4th is fine. The H55 really needed 6 gears.

You'll either be over revving in 2nd or lugging in 3rd if you're going a certain speed.

The H55F is better off road because of the lower 2 gears, Though I often still tool around in 2wd low. The H42 was more fun to drive around town with stock tires. The H55F is quieter than the 4 speed.

Having the H55F now in my cruiser for 26 years and counting, I'd never go back to the 4 speed.
 
Output Shaft

Thanks for the revised info. This stuff is a big help.

What got me thinking about gearing are the facts that on trails I often use low range not because of the slope but to keep the speed low enough the Cruiser and me don't get shook to pieces but keep RPMs in a good zone. That plus just pulling into my slightly uphill driveway in 1st gear it takes a lot of throttle to keep it from lugging - that or milk the clutch. The driveway is short, it is gravel and I have to get get real close to the wifes car.
 
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