What gear ratio.

[ThatOneGuy]

Im getting ready to pull the rear axle from donor explorer, and noticed its got 3.55 gear ratio, ive also got 3.73. Which would you run for a in town chore truck, with some highway, heavy snow, occasional easy trail runns.

 

[Dirtman]

4.10... or the lowest gear you have available.

3.55 is junk for anything but highway mileage unless you're running go kart tires. 3.73 probably wouldn't be horrible if you keep the tires stock size.

 

[Curious Hound]

Yup. What he^^^ said.

 

[racsan]

I highly recommend 4.10’s I originally had 3.45’s on my current ranger and 4.10’s made a huge difference.

 

[ThatOneGuy]

I was actually wrong on what the other axles are on my other parts rig its got 3.27 so i think thats what ill use i like bigger tires. This is kinda a pain though since i have an 8.8 ls disk 3.73 off a 98 i was hopeing to use its been in my shed for 10 years lol. But i guess that just means itl be easyer to put a locker into lol. How straight forward is it to disk swap a drum axle.

 

[Dirtman]

Using 3.27 ratio you better have friends to help you push start the truck and always drive down hill...

 

[ThatOneGuy]

Id love to have 4.10s but ive never seen them in a parts yards around here. At this point in time i cant budget that. Gotta use what i have.

 

[ThatOneGuy]

Using 3.27 ratio you better have friends to help you push start the truck and always drive down hill...

Can you explain i dont know eveything lol

 

[Dirtman]

Can you explain i dont know eveything lol

The lower the numerical value of the gear ratio the less low end torque you get. I.e a 3.27 ratio has less take off power than a 3.73 ratio. The higher the number the more power you have but loose highway speed/mileage.

Tire size effects this as well, the larger the tires you use the higher "numerical" ratio you need to compensate.

For say 31" tires...
3.27 sucks
3.55 sucks
3.73 is "OK-ish"
4.10 is good
4.56 would be beastly


If you run large off-road tires you even want to consider 4.56 to 5.13

 

[ThatOneGuy]

The 93 sport i drive also has 3.27s ive never had problems. It does well off road i.e. sand mud gravel, running 235-75-15s. Id like to jump to 265-75-15

 

[don4331]

Drum to disc swap is super easy - use an Explorer axle; use F-150 lowering brackets to change from spring under to spring over.

On a more serious note - swapping Mustang rear discs isn't that difficult but here are the cavaets:

Mustang discs are better than not functional drum brakes (and about 90% of drums I see haven't been maintained and are effectively non-functional).​

Mustang discs are slight better than 9" drum brake when both are working good​

Mustang discs are WAY worse than 10" drums when both are working as designed. Exception: the ebrake application of Mustang calipers is WAY better.​

Explorer disc don't mount on Ranger axles but are about the same improvement as 10" drums are over 9" ones.​

​

If you install rear discs you MUST change the residual pressure valve - drum brakes require 10psi, discs only 2. If you don't change them, you will go through rear pads like you owned shares in the company.​

​

Lastly, the Mustang rear brake's ratchet mechanism for the ebrake, requires they work when by applied by a 90lb weakling using arm strength. When applied by 300lb lineman (aka my son in his Mustang) or foot pedal (aka my daughter in her Ranger); they won't release properly. So, for 1st few miles, you will be wearing off pad.​

​

But they do add bling over drums.​

 

[Dirtman]

A manual helps some, as does putting the transfer case in low. But 31" tires with 3.27 gears is just mind boggling bad.

 

[ThatOneGuy]

Ok so for my build would you guys recommend that i hold off swapping the d35 and 8.8 into my 83 with d28 , 7.5 with 3.73s. Untill i acquired better gears, like i said this isnt a monster off roader but i do like to play some. Or would the 3.55s be suitable for awhile till i could swap gears. As far as the disk swap my plan was an explorer axle pehaps ill just keep my 3.73 d28, and use my 8.8 l.s. disk rear, already have new mounts for it. Than switch the d28 out when i find gears for the d35

 

[don4331]

235/75R15s are trace under 29"; 265/75R15s are about 30-5/8". 3.55s with the 265s would be more/less equal to your 3.27s with 235s.

But my son's 2wd runs 3.55s with a 4.0 and 225/70R15s - a little under 27-1/2" and I figure it would be nicely picked up with the 3.73 axle I pulled when I installed the 4.10 one in my Ranger (to run 31x10.5R15s - same size as 265/75R15s).

 

[Dirtman]

I have 225/75/15's (roughly a 27" tire) with 4.10's and wouldn't dream of putting a larger tire on until I get 4.56 gears in it. Mine is auto, if it was manual I would probably be happy to go larger without the need for 4.56.