I have a 2wd 5spd and it has a axle gear ratio of 3.583 and i wanna swap those out and get a higher gear ratio for better gas milage any recommendations on a gear ratio? i was looking at 5:29s? does that sound good? I also have the w55 trans which is weird cuz i thought they didnt put them in the 89 and up models anymore?

 

no that will get ya worse gas mileage!

you want a 3.07 or a 3.90. a 3.583 is a lot better then the 4.10 that normall comes in the trucks, so count your blessings there. A tip to maybe help the gas mileage is putting taller tires on the truck. It will kill your acceleration, but on the freeway you will get better mileage if you keep your foot steady.

I switched from a 4.10 to a 3.07 and it was a huge difference in performance, and i got my mileage from 22ish to 30ish. I might swap in a 3.56 though cause the 3.07 puts a lot of strain on the transmission at freeway speeds.

hope all the info helps

 

yeah but i dont think mine are 3.583s then cuz it doesnt get great mileag. Igot it from a chart online but how can i truly tell what my gear ratio is?

 

if its the orignal axle in the truck you can go off the body sticker...
this page explains it http://www.brian894x4.com/Gearratiosanddiffs.html

if its been swapped out jack up one wheel in the back, put the trans in neutral, put a white mark on the tire and a white mark on the drive line, spin the wheel 2x around and count how many times the line goes around... it should go around 3.5ish times if you got a 3.56 axle. if ya got a 4.10 axle it will go around 4 and a little more times...get it?

 

Yeah i just did that like five mins ago and it looks like i got 3.58s so anybody know where i can get some 3.29s or the lowest possible thats still safe to use??

 

im useing a 3.07 and its safe... like i said though its really going to effect how your truck drives...

 

Are you using it in a 7.5" axle or 8?

I was really hoping to throw in some 3.29s or somethin close but i cant find anything!?

I can deal with losing a little acceleration if it makes up for it with mpg's

 

Are you running a 7.5" or an 8"? Is there a 3:07 for a 7.5? I'm running a 4:10.

 

I have a 7.5"

Im not too sure if there was a lower gear for it though, I was hoping you guys knew :/

 

Hmm, sure your truck isnt running in tip top shape?

What kind of mileage are you getting now? High 20's are very easy. Low 20's there is something wrong.

A good, fresh, crisp motor will get better mileage anyday over a so-so worn one.

I just think that you start at the basics, because changing gears isnt the easiest or cheapest things to do. And second, my rock stock 82 with a 3.42 (not very different than yours at all), and a four speed got over 30mpg consistantly.

Just trying to help.

Edit-One other thing, more gear does not always equal more mpg's. Motors need to run at near peak torque at cruise. So adding a tall 5th, getting the motor out of its "range" will burn more fuel because its being lugged.

The w58's tall 5th hurt mpgs when I was stock, for that very reason.

 

Raff - well its ok i was really just hoping for better i average 25-26 mpg i just want more ive done everything in maintenance already ex spark plugs, wires, oil, diff fliud, trans fluid, etc...

I also hate running at 3000 rpm barely going 70mph
Its very annoying and i dont like it cuz it wastes my gas

 

I agree, a 3:42 and my W50 will work just fine for me. Just gotta find a 3:42 diff and of course have the money for it
Right now on the freeway at 60 I'm running around 2900rpm in 5th. That could use some improvement. With a 3:42 it's more like 2400rpm. I usually pull pretty decent from just above 2000rpm, in fact I can take hills at 55 in 5th with no issue, so I could get away with the 3:42s.

if you've got 3:58s a 3:42 isn't gonna be a huge difference though. Maybe 100rpm? I'd tend to agree with Raff, you should go over your engine first.

 

Well ill admit I do have a lead foot and if i can get a hold of some 3.42s imma put em in

Honestly it gets good mpg but I live near sac and my parents live in so cal its about a 800 mile commute back and that i do about once a month and i really think itll be worth it to run at 2800 rpm for 700 of those miles then 3000 rpm for 700 miles

Heck id save myself about 140000 rpms on the trip!

 

those roads out there would be nice on a good sport bike. 45-60mpg. just sayin

 

He'll yes! I want one soooooo bad but if you see the way people drive over here you'll change your mind quick its like every other day i see an accident

 

W58 will make your cruise happy!

 

Yesss! i was looking at that but im pretty sure those are hard to come by

So i was thinking since theyre both a W series maybe i can swap the w58 5th into mine instead of the getting a new axle gear?

any info? what do you guys think?

 

You like take the trans apart and install the 5th gear?

I think would be easier, cheaper and smarter to just change the whole trans. Just my opinion though. Why would you open up the trans to add one more gear when you can just swap the entire thing. They might be hard to come by but would still be easier and cheaper i think.

Go look in the other thread how much the guys were saying it cost to repair their transmissions. I would assume to add another gear would be around the same price range.

 

i have the 3.73.... keeping it at a steady 60mph or less will get me far... lately ive been getting 22mpg

 

I got the 3.07 8" it's a dog off the line but MPG champ especially w HAC kit.
I'm trying to rig up the HAC to lean out the carb even more while at hwy speeds trying to touch the 30's
I know I get best mpgs at 62 mph or less - 26.5mpgs 90% hwy
yeah its slower than everyone else, but I get there, on time so don't worry bout how other people drive, I'm not a sheep to follow.
above 52 mph aerodynamic drag plays a big effect on ENGINE LOAD and mpgs tend to drop the higher the engine revs, torque peak be damnd. It says plain and simple in the originals owners manual that came in the truck - the faster you drive, the more fuel.