First post...question on axle ratios

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Nov 5, 2004 | 06:49 PM

#31

89ford73

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finally!!! someone with some sense!!! you should be running 2200 at 50-55 mph, thank you for clarifying that SLA. and yes, the 4.10 is rough around town, i just don't ever use first gear when in town. if you use first a lot, try not using it at all and skip a gear every once in a while. i like to skip 3rd myself. i just shift 2-4-5 hope to help you out a little

Nov 6, 2004 | 09:54 PM

#32

bowedup2003

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89Ford73,
Don't be so quick to cuss someone's statementjust because your truck does not perform the same. I have an IDI with ZF 5 speed and 4.10 gears and on the highway running empty I get 18-20 mpg consistently. The lowest MPG that I have ever gotten was pulling our 24' gooseneck with a F600 ford truck and a load of machine shop equipment was 12mpg. That was driving with my foot nearly flat on the floor. If your truck wasn't turned up so much your mileage would be better, or could it be because of other things, like driving habits...

Bowedup

Nov 6, 2004 | 10:04 PM

#33

89ford73

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well then ya'll's trucks must not run very good or somethin.i dunno, 18 mg is pretty good for any diesel, my granda said he got 18 when his 84 with a 6.9 and t-19 with 3.55's was brand new, but quickly dropped off after the first 2 years or so. but theres still the fact that 70 mph on the speedo does not come anywhere close to 2200 on the tach unless you got a 5-speed and 3.55's its just a fact, that im trying to prove. but

@#$@%$%#@!%$@!$!#$%#@%!@#% it makes me mad

when people

i should just forget it.

Nov 6, 2004 | 10:12 PM

#34

89ford73

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and i bet sla gets comments all the time like "man that thing runs GOOD for an old diesel!!". well thats cuz they have never rode in one that has 4.10's before mine runs great, get-up and go is real good, rebuilt and turned up i.p., new injectors and glowplugs. i spent a lot of money and a LOT of time on it just to get it running-starting good. its never acted up not one time since i got the "air in the fuel system" problem fixed and i am happy with it. the cold weather still gets to her, but a little ether fixes her right up in the cold mornings. what can you exect from a 330,000 mile engine? i get 12mpg pretty easy

Nov 8, 2004 | 08:12 AM

#35

ditch witch

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Joined: Apr 2003

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From: Kansas

Dave, I know we've gone thru this before, but I've got a 3.55 rear axle to replace a 4.10 in a '84 with a 4 speed (T-19) and 235x85x16 stock size tires.

What will the RPM difference be? Your opinion of not having pulling power with 3.55? I do pull a stock trailer 10% or less of time, and trailer with machinery some. I'm in flat lands of Kansas!

Another reason for the change: the 3.55 is LS to 4.10 is not. This long wheel base with 2 wheel dr. won't pull up a slight slope in morning dew!

Nov 8, 2004 | 10:24 AM

#36

bowedup2003

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89fORD73,

You need to ease up buddy, I have a full rebuild on mine as well, roughly 20,000 miles on fresh EVERYTHING. I have 4.10 gears and a ZF 5 speed and as stated earlier I do get very good fuel mileage (18-20). And I guarantee that my truck has seen way heavier loads than yours and has pulled very well every time. You need to ease off of the griping and consider that all of that black smoke coming out of your pipes is unburnt fuel and that is where you mileage is going.

Bowedup

Nov 8, 2004 | 06:45 PM

#37

Dave Sponaugle

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Joined: Nov 2003

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From: Nutter Fort, WV

ditch witch, in Kansas a 3.55 rear should work fine for you. I am in WV with not one flat spot more than 10 feet across for miles. I regularly pull equipment that puts my gross over 23,000 pounds for 60 to 100 miles one way with my 3.55's and 285/75-16 tires that are 33" tall tires. Me and my truck weigh 8060 pounds and I have about 1500 pounds of fuel tank, tamper, and other digging tools on it most of the time.

Using a 31" tire diameter I figure you are turning 2448 RPM at 55 MPH with your 4.10's.
Using a 31" tire diameter I figure you will be turning 2120 RPM's at 55 MPH with the 3.55's.

It is not gonna be a fast towing machine, but you should be able to save some dollars at the fuel pump when you are running around empty.

I pulled loads like I am pulling now when I had the 6.9 in my truck.
Several grades around here are over 12% and I went right up them dragging a 3,500 pound trailer with a 10,000 pound mini excavator on it. I was not moving fast, but I went up the hill.

How much weight are you going be pulling?

Nov 8, 2004 | 06:58 PM

#38

ditch witch

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Joined: Apr 2003

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From: Kansas

Dave, I appreciate the help. I have a trailer which weights about 1200# I'd guess and I sometimes have an R-40 trencher on it. Total of trailer and machine might be 7500# and if I use this truck to pull it I would only be going 25-30 miles or less. Since I almost never use 1st gear I figured the lower ratio would allow the use of the lower gear and better econony with 4th.

I've got everything lined up to make the switch, including help, but a friend told me it would be a dog, and I wouldn't be satisfied. But he drives everything hard and I'm quite the opposite. I think I'll do it tomorrow!! Thanks again.
len