crawl ratio

[camcruiser13]

I am very curious about the Orion. The PO of my 77 fj40 changed out the diffs for some 3.70's I think. It's great running around town but can't imagine trying to crawl with it. 4low is still pretty fast. Is the Orion an addition to my transfer case or a total replacement? Would it only affect 4 low? Not trying to hijack, just trying to understand the consequences of each choice. Thanks, Slow Poke

no it is a replacement tcase.

 

[Slow Poke]

Orion

OK, it's a complete swap out with my original. 2 Hi and 4 Hi are just like normal but 4 Low is geared much lower. Do I have that right? In my brief run through of the Orion sticky there seem to be some issues ( popping out of gear and excessive wear at break in..) Have these been solved? What other issues do the Orion have?

 

[Poser]

He is going to 35s .. it is a '78...

so to keep a stock ratio, if everything measured exact-

29/35 = 4.11/x

29x = 35*4.11

x = (35*4.11)/29

x = 4.96.. shoot he's taller than stock even

So I take it, you do not care about the “overdrive” that exists from installing 35” tires on the 4.11 gears?

 

[venpick]

He is going to 35s .. it is a '78...

so to keep a stock ratio, if everything measured exact-

29/35 = 4.11/x

29x = 35*4.11

x = (35*4.11)/29

x = 4.96.. shoot he's taller than stock even

wow nice algea braaa
so 4.88 is gonna be like stock. I didnt think the stock ratio was very good so thats why i did both the r and p and the transfer and tranny. hovever like i mentioned wait untill you can pay for the locker at the same time to prevent you from having to set up the differential 2x. also get longfields at the same time cuz with that size tire and any lower gear combo the birfields will pop x2 with a locker.

to quote randys ring and pinion

Here's 4 Reasons To Change Your Gear Ratio. (ring and pinion)

If you have larger than stock tires on your vehicle, the benefits of gearing CANNOT BE MATCHED BY ANY OTHER MODIFICATION TO THE VEHICLE!

By regearing it is guaranteed that:

1. TORQUE TO THE REAR AXLE WILL BE GREATLY IMPROVED
Even a simple change from a 31" diameter tire to a 33" diameter tire will affect the amount of available torque by 10%.

2. STRESS TO THE DRIVELINE WILL BE GREATLY LESSENED
Modern day transmissions cost $600 or more to perform a basic overhaul. Driving with even a 10% larger tire will result in the transmission being under the same load as always being driven on an incline. The transmission may not suddenly fail, but the life will definitely be reduced by thousands of miles.

3. ENGINE EFFICIENCY WILL BE REGAINED
RPM alone does not affect fuel mileage. An undergeared vehicle (as the result of oversized tires) will result in a substantial loss of fuel mileage. Also, just as with the transmission, your engine life will greatly be reduced.

4. SPEEDOMETER/ODOMETER ACCURACY WILL BE REGAINED
With kits in the $100+ range to calibrate speedometers after tire swaps, it seems pretty important to have an accurate speedometer, which can also be fixed with a simple gear change.

Don't put a bandage on a serious problem. By installing the proper gear ratio, easily determined with our gear calculators, you can save thousands of dollars and days of vehicle downtime, plus have a little fun to boot.