Axle code is 01 (3.73) and the window sticker says 3.73 but its apparently a 4.11. 70 mph I'm turning 23-2400. My 95 is 1950rpm at 70. I try to stay at 2 when running down the highway for mileage. I'm planning on having this thing a long time. Should I change it out to a 3.73? I rarely pull anything and what I do pull a 6 cylinder could pull easily.

 

With an AT, that's about right. Don't know about the "01" Axle Code:

 

I'm sorry C1

 

You would likely see an improvement in fuel mileage. Is there a consensus on this?

So over the long haul, the cost of the gears would pay off, but it will take some time to pay back, unless fuel prices go back up and/or you drive a lot.

Then there is less wear on the engine with about 18% lower rpm. It is amazing those school buses last so long running the high rpms and shifting up and down like they do with the frequent stops. So if you want long life, the gear change might be worth it to get 500K out of the engine rings and bearings! Also, lower rpm, means fewer injector operations as well. They don't give them away.

 

2000 rpms = about 62 mph with the 4.10 in this truck. IIRC 2000 rpms = about 72 mph in my old Ex with 3.73's.

I agree that you probably have a 4.10 ratio.

A big question for the cost of the swap: Is it a 4x4 truck?

There are plenty of times when I wish there was something to bridge the gap between 3.73 and 4.10 for the Dana 80.

 

I have a 4:10 and my RPMs are ~2100 @ 65 MPH. What is the overall size of the tires that you have on ? I am around 31 to 31.5 inches.

BBD

 

They are stock 235/85/16's which I believe translates to 31.5-31.7 inches in height when new.

 

My advice would be to find a trading partner. When I had my big GN horse trailer, I would have liked the 4:10's.

 

I'm at ~2000rpm at 70mph.

 

Sounds like 410 for sure

 

Actually there wouldn't be a cost, so to speak. I could swap the rear ends. My 95 has a 3.73 for sure. Its my work truck. Anytime I would go anywhere, road trip would be in the 01. As far as the 500K, my 95 has 406K and runs like a top. Prior to owning the 7.3 I had two 350's one had 312K and the other had 413K both still running good when I got rid of them. I see comments about "high mileage" 7.3's at 250 or so. Spot the shop truck went almost 800K and it was tortured.

 

USE CAUTION!

Though the axle tag is usually correct, who knows what "user mods for improvement" may have been done.

If this is a 4wd - best make dang sure the ratio is the same front and rear!

Ford at times (but not all the time) ran the front a tiny bit steeper on the front to maintain slightly better front end pull and steering. This is good.

Excessive difference between front and rear (oh, yeah - you will feel it) will DESTROY very expensive parts!!! (Ask me - never mind, I'll confess. Bought a 4x4 the PO switched rear end ratios - cost a good bit to set right).

Also, the 3.73 will deliver better fuel mileage. 4.10 better low end HP and torque. 3.73 to 1 compared to 4.10 to 1.

BTW - this is just one more reason I despise auto trannys. Gear ratio from a manual to differentials is fairly easy to determine - autos not so much! If the differential has been rebuilt with a different ratio the axle tag can lie ('cause some dang fool got lazy) and cause you to go crazy!

 

No its a 2 wheel drive. It was my brothers truck. Took me several years but caught him at the right time and he sold it. This mileage thing has me confused though. 2,3,400K seriously, this is a diesel 1 million. Gas will do the 3-400K all day long3.

 

The base engine long block is good for a lot more miles than all the EPA required mods allow. Thank your FedGov for neutering the most durable fuel efficient engines ever designed - big bore diesels.

 

Your 95 has either 3:54 or 4:10.