What is the highest (2.7x-3.08 exc) rearend that my little 2.3 can handle?

[chsw]

I have a decient sized tire, 2.3l 86 fordranger I swaped from a auto to a 4 speed I yanked from a 84 2.0. I can start in second gear all day long and was wondering how low (high?) I can go with my rearend. Right now it has a 3.73 but I want lower rpms when I take it on the interstate. I live in bumfu** egypt and will have a 30 min comute to my new job. Have the money to do it now so I need to do it before gas hits 4 bucks a gallon again. Thanks for any advice.

 

[Captain Ledd]

The 4 cylinder engines generally get a bit better mileage in the high RPM's.

I can only guess being a 4 speed, it does not have an overdrive.

I digress though, the lowest ratio for either the 8.8" or 7.5" is 2.73.

However, I would urge you to try a 3.08 or 3.27 (also common ratios), and are probably going to be easier to find in a Ranger axle already assembled. The 2.73's generally found their way into mustang rear ends believe it or not.

Save your original axle to swap back in just in case.

 

[chsw]

Right now at 70mph I am running about 3100 rpm, The calculator I was using claims a 3.08 will drop me to 2500 rpm, makes me think 600 rpm less will get me better mileage. I hope I am right with how much people want for these rears.

 

[Sunk]

That's not too high. My truck is just a little lower than that at 70. I'd try slightly larger tires on the rear first; that's both cheaper and easier to change if you don't like it.

 

[85_Ranger4x4]

That's not too high. My truck is just a little lower than that at 70. I'd try slightly larger tires on the rear first; that's both cheaper and easier to change if you don't like it.

With the price of tires anymore a 5 speed may be cheaper, and then you won't have a gutless turd at lower speeds.

 

[kryptonitecb]

Lower rpm's doesn't translate to better gas mileage. I would try to match the rpm's as close to stock as possible. Try using the gear calculator to find what gear ratio for the rear end puts you as close to stock as you can get. Over drive will make a huge difference at highway speeds also.

Sent from road while ignoring traffic

 

[Captain Ledd]

Right now at 70mph I am running about 3100 rpm, The calculator I was using claims a 3.08 will drop me to 2500 rpm, makes me think 600 rpm less will get me better mileage. I hope I am right with how much people want for these rears.

Actually yeah, that isn't bad at all. Some people have these thoughts (drug induced delusions) of running a 4 banger like a big V8, 1,500-1,800 rpm, and it doesn't really work out for them.

2,500 RPM is pretty good, you just might see some better mileage out of that. If you were towing a lot the higher RPM would be better.

for the rest of you, Non-overdrive transmissions generally have a much deeper starting gear (or at the least somewhat deeper). And without that extra cruising gear, you kinda just have to deal with the occasional shaky start depending on the load. And he's already said he can start in 2nd gear. It doesn't sound like he's running a particularly large tire either.

3.08 would be a good ratio for his application.

Just like how I'm going all the way to 4.56 with my 29" tall tires. Most would say I'm nuts for going that deep. However, my 5th gear is almost un-useable, basically 5th gear would now be equivalent to fourth gear and I get a bonus of easier starts.

It all depends on the application.

 

[85_Ranger4x4]

Actually yeah, that isn't bad at all. Some people have these thoughts (drug induced delusions) of running a 4 banger like a big V8, 1,500-1,800 rpm, and it doesn't really work out for them.

Even V8's don't like that around here...

 

[Hagan]

Why not just swap in a 5spd? You will get an overdrive ratio and that will lower your RPM's like you want. In my opinion its cheaper/easier to do that.

 

[4x4junkie]

A 5-speed trans swap gets my vote also.