Best gear ratio for 4 speed, highyway and pulling..

[6.9poweredscout]

i'm on the lookout for a rear dana 60, i have the front, i think it's a 4.10. should i keep it at 4.10 or go to mabe 3.73? i would like to be able to cruise 65 and not have the rpm's maxed out, and i plan on taking it to the truck pulls to see what my little binder's got!

-Jon

 

[The Warden]

IMHO 3.73 is the best "compromise" gear ratio...4.10's are great for pulling, but especially with a 4 speed, aren't the best choice for empty freeway cruising. 3.54's are great for empty freeway cruising, but aren't the best for pulling. IMHO if you can't get a 5 speed and/or an OD unit, I'd go with 3.73's.

If 3.73's aren't an option, I would be asking myself which purpose I plan to use my truck for primarily...if cruising and fuel economy are the most important, I'd go with 3.54's, but if pulling is more important, I'd go with the 4.10's.

BTW, with a T-19 and 4.10's, my engine would hit the governor at between 75 and 80 mph, and sounded like a 2-stroke Detroit at 65 (even before the turbo and the disappearance of the exhaust system ). I averaged 14 with the T-19, and I average 16 to 17 with the ZF (and I've broken 20 on a couple of occasions). I was seriously contemplating switching to 3.54's, but decided that a ZF and an OD unit would make the truck more versatile. YMMV...

Just my $.02

 

[hesutton]

The 3.73 will be a good compromise between the 4.10's and the 3.55's commonly found on Ford IDI's. I have a T19 and 3.55's riding on 37 inch tires. I cruise at 70 right at 2250 or 2300 RPM. Don't tow a bunch but I had right at 4000lbs in the bed last saturday and I didn't really notice it with the 3.55's. But, if you are going to tow heavy, the lower the gearing the better.

Heath

 

[gsgIDI]

Hi,
I have a 4.10 in my diesel and at 65 mph and 1950 rpm I get to watch the fuel gauge really move possibly 10 or 12 mph. I topped back tank today and got mileage I only used 6 gallons in 64 miles. 10 miles to the gallon, if my math is right. When I bought the truck it had 4:10 gears in it, maybe later I'll switch to another gear ratio for economy, I do not have anything to pull that is heavy. I have a F-150 6cly gasser with 3.73 gears I might be getting 14 or 15 mpg thats all. I bought the truck with the 3:73 gears already in it, I barely can get it to move itself much less pull anything. gsgIDI

 

[david85]

My fuel economy was 9-13 MPG with 4.10 gears and C6 transmission.

 

[6.9poweredscout]

the D44's have 3.54's but i think the 6.9 will make quick work of em... i was thinking 3.73's too, i think that'll be the best bet for what i'm going for, i mean it is under a scout so i'm not going to haul equipment or anything really heavy, mabe just my green scout. the guy on the binder bulletin with a 6.9 scout and 3.54's said it'll carry it's self away at 115mph and keep going! i take a yearly "migration to the homeland" in southwest ohio for a International truck show which is roughly 1000 miles round trip. that's the main reason i want decent highway gearing. i'm also planning on going with some cable actuated OX lockers, but that's not immediately!

Thanks!
-Jon

 

[mankypro]

Weird my truck had 4.10's I swapped to 3.7's and tossed in a GV behind the t19 I get between 18-20mpg about 16 with 2 tons in the bed, now that I have a turbo I should see a couple more mpg.

I do about 2,300rpm at 70mph in 5th od

 

[david85]

the D44's have 3.54's but i think the 6.9 will make quick work of em... i was thinking 3.73's too, i think that'll be the best bet for what i'm going for, i mean it is under a scout so i'm not going to haul equipment or anything really heavy, mabe just my green scout. the guy on the binder bulletin with a 6.9 scout and 3.54's said it'll carry it's self away at 115mph and keep going! i take a yearly "migration to the homeland" in southwest ohio for a International truck show which is roughly 1000 miles round trip. that's the main reason i want decent highway gearing. i'm also planning on going with some cable actuated OX lockers, but that's not immediately!

Thanks!
-Jon

Not sure if you know this, but the dana 60 and 50 will go as high as 3.54 gears as well. The D44 will go as far as 3.07. Unfortunately for me, no 3.07 ratio for the high pinion dana 60 so my 4wd conversion remains half done....

 

[6.9poweredscout]

yea, i want it as low as possible but still comfortable on the highway.... i'll see how i like the 3.54's, i'll see if they hold up at the pulls, or even make it that far!

ALSO with the D60's the springs will be OVER the axle opposed to the stock under the axle, so i'll have to swap back to stock springs (has a 4" lift now) and i'll probably run in the 33-35" tire range (mabe a set of 33's for pulling and 35's for crusing... haha ).

thanks guys helpful ssooo far!

-Jon

 

[mankypro]

I was stuck with 3.73's they were the tallest gears available new from yukon or the other vendors.

 

[david85]

There is a 3.54 ratio for the D50 and D60 reverse cut front ends and they are available from factory. But as far as the aftermarket is concerned, theres no money in offering tall gears for what is usually used for agressive off roading, so instead they prefer to offer much lower gears like 4.10 and also much lower. This is why I will probably never go all the way to 4wd even though I have a working transfer case in my truck. There is no 3.07 ratio for the dana 60 and the dana 61 will not fit a ford without extensive modding.

 

[FordGuy100]

I like my 3.54's....its pulls well, probably not as nice as 4.10's but your ears wont be ringing as much . Seriously though....I wont even lie 3.54's in my truck are probably a better pulling gear than 4.10's. If I start to loose some momentum on a hill, just downshift into 3rd and I can stay at 55-60mph all day long. Maybe with 4.10's I could stay in 4th so I might be wrong there.

 

[Dirtleg]

I don't have a t19 but have pulled alot with 3.55 gears and 34" tires. My truck is NA. It's quite hilly around here and I have pulled as much as 15,000 lbs. Usually in the 8,000 - 10,000 range. Those are just the trailer weights. Without the OD on my gear ratio is 1:1 at the tranny so comparable to a t19 in 4th gear. I can pull most roads around here just fine. On some of the really steep sections I'll drop it down to 2nd but I've always been able to maintain 45-50 mph in these conditions.

I imagine with your lighter truck and turboed motor you'll be fine with the 3.54. I can get 20 mpg on occasion empty but I do have the overdrive to use when not pulling.

 

[david85]

When it comes to power, the only time you notice a difference between two different axle gear ratios is when you first start out. After that, you just stay in a lower gear for a longer time before upshifting as you accelerate. Keep it in the powerband.

Going from 4.10 to 3.08s sounds like a stretch, but in reality I can drop to second gear with 3.08s and a final drive ratio that is close to 4.10 gears and in top gear (when I had the C6 3 speed).

The truck should be geared for what you use it for most. If I never had to go above 40 MPH I would have left the C6 and 4.10 gears in there. But since I go above 80 on ocasion, I don't mind loosing a slight amount of neck snap under 10 MPH (when towing that is). For those situations where I am dealing with a really heavy load and a steep incline, well thats what the transfer case is for. More for fun than anything else.

 

[RKOCH]

Go with the 4.10's 65 or 70 is all you need and can pull a house with you.