Need some gear ratio advice.

[bowtieboy77]

I have a mixed year ranger its a 86 chassis reg cab with a 88 2.3 carbureted and m5r1 5speed trans. The problem is its a screamer at about 45mph its reving about 2200rpm's in 5th. The chassis would have originally came with a 2.0 with a standard (not sure what trans as engine and trans were pulled). I am putting it back on the road and will be replacing all diff brgs and seals. The ratio that is in it is a 3:45. The low end gears in the trans seem to be quite close togeather so losing some take off torque to save high gear rpm's should'nt be a problem. I would like to drop about 500rpms in the top cog. From what I have seen available 3.08 are the next highest ratio available from a 3.45. So my question is would this ratio drop my rpms to were I want them? Or does anyone have a similar set up and have a opinion. I am just using the truck as a daily driver and going for decent milage. If I want to race I have my other truck for that. Any opinions is respected and appreciated.

 

[Mikel89us]

Most of us like 4.10s. The easier option is bigger tires.

 

[RonD]

M50DR1 should have 3.72 / 2.20 / 1.50 / 1.00 / 0.79 / Reverse = 3.40

This site can give you RPM vs speed, don't use comma in RPM, 2000 not 2,000
http://www.angelfire.com/fl/procrastination/rear.html

Measure how tall your tires are now, i.e. 25", 26", 27", ect....
Just change rear axle ratio to see what works best for you

 

[bowtieboy77]

I'm alittle confused by the 4.10 suggestion that would bring my rpm up even higher. It would turn it in to a stop light racer but even worse on highway then right now?

 

[4.0B2]

A higher (numerically lower) gear will not always give you better MPGs.

 

[bowtieboy77]

That is true if I loose to much torque and lug it my mpg's will suffer. The 3.45 do work well and it will pull most hills in 5th just wish I could get the rpm down about 500rpm at 45mph. It might not be possible I guess. Thats why I'm looking for opinions before I invest $150-200 on a 3.08 gear set. I am going to try out the web site Ron D suggested. Thanks for the suggestions this far.

 

[4.0B2]

Grim reaper jeeps has a nice gear calculator to.

3.21 not an option?

 

[bowtieboy77]

3.21 could be perfect I did a quick search on jegs and summit only found 3.08. But that would be a ratio between 3.45 and 3.08 might be worth a try. If I get them cheap enough I can switch back if I don't like it. I am a licensed tech so I won't be paying labour charge just cost of gear set. I'm going to my auto store tomorrow my friend runs it and he has a very impressive performing charger drag car (impressive for a mopar lol) I will see if that ratio is available and what his thought would be. Thanks 4.0B2

 

[4.0B2]

A lot of explorers came with 3.21's but that's 8.8.. I'd search junkyards for some stock gears and just swap the entire axle. Usually $100 or so for the complete axle at a u pull it lot.

 

[Sunk]

Bigger tires were suggested. I'd go that route, it's much easier to adjust by small amounts.

 

[XLTsplash]

The 2.3Ls like to be 2,000-3,000 RPM when driving along, I think you will end up lugging the engine if your driving along at 1,700 RPM.

 

[Kenneth S]

On my 86 with a Holley 350cfm carbed 2.3, M50D-R1 5 speed, 3.73 gears, and 215/65.16 tires. I get 22mpg city, 27mph hwy. My brothers 92 2.3, same transmission, 3.45 gear, with 205/70/15 tires, and it was a dog had to shift out of od to go up a hill. I put a set of 3.73's in it, now it can go up those same hills without having to shift out of od, and gets better gas mileage (plus it can spin the tires, it couldn't spin them with the 3.43's). If you go to 3.21's, or 3.08's it will be a really be a slug, and your gas mileage will be in the toilet.

 

[Mikel89us]

I said something about the 4.10s because they work great on these trucks. And as mist are saying, if you try to drop the rpm you will hurt fuel mileage and drivability. If you really want a 3.27, they were common in the 7.5 in the mustang and explorer 8.8.

 

[4b316]

You must have some small tires for it to be turning that many rpms in 5th,do you know it was 3.45,s or just what the tag says?I,d pull the cover to be sure.

 

[bowtieboy77]

Thanks for all the replies lots to think about. And yes the tires are only 14". I'm planning on keeping tire size the same.