3.73 limited slip axle ratio

[mcompton1973]

ok, I looked up the codes, and I found that this is my axle ratio. Now what I can not remember is if a biger number means better take off power, or lower engine revs at highway speed and therefore better mpg. that is the main difference in the ratios corect?

 

[Blockay Sockay]

The higher the number, the lower the gear; therefore, you'd get better take off power then mileage.

 

[CDW6212R]

3.73 means 3.73:1 ratio. A 4.11:1 ratio is a larger ratio than a 3.55:1 ratio.

These are the ratio of input RPM's to output RPM's. The 3.73 is an excellent ratio for the heavy Explorers. A lot of the later SOHC V6's have 4.11's.

The later 2002+ V8 Explorers have an extra gear, a "lower" first gear. That 5R55W has a higher ratio first gear(3.22:1) than the 302 Explorer trans' first gear, which is 2.84:1.
I don't know what rearend ratio they have, but their second gear is about the same as our 302's first gear. We could achieve the same acceleration in the 1-4 gears, if we had the 5R55W and a 3.08:1 rearend ratio.

The lower ratios like 3.27's or 3.55's, will lower RPM's at speed, compared to higher ratios like 3.73's, or 4.10's.

Notice I used the accurate term ratio, not gear. Anyone can understand ratios because it is basic math. Talking about gears is not talking about ratios, that is, it's 1940's based terminology. It doesn't make sense, it is about what gear you are in, low gear versus high gear.
Regards,
Don W

 

[unclemeat]

Axle ratio is defined as the number of revolutions the driveshaft (pinion gear) has to complete for one revolution of the axle (ring gear) or tire to complete. The mechanical advantage means that the more revolutions the drive shaft spins for one revolution of the axle the greater the torque. More driveshaft revolutions (higher ratio, lower gear) means more engine RPMs.

 

[AspenX]

My 91 4dr had a 3.73 and my 96 sport has a 3.27. The 3.73 was quicker off the line even with a bigger heavier truck. It also got 2 mpg better on the highway.

 

[lowflyingbird]

I have the 373 set in my 99 2wd. Previously I had an Aerostar 4.0 witha 8.8 which had 355. I have to say that the 355 ratio was more friendly on the highway,OBVEOUSLY DUHHH, I know. I find that my 99Explorer with the same 4.0 OHV just needs to be pushed on the pedal too much @ 65-70 mph, @ 2400rpm. I plan on swaping out the 373 to the 355. NOT TO WORRY, its soon (spring) to get a blower. So I'm not really worried about off the line performance.
Keith

 

[LC1500MB]

Where can I find what the codes mean?..mine reads D4 for the axle...

 

[CDW6212R]

It's easier if you crawl under the truck and read the actual tag, ratio. I believe the "D" means it has a traction lock. It's probably a 3.73 though.
If you look at the tag, the ratio is right next to the bolt head, it will likely read "3L73".
LOL
Don

 

[03ExplorerSPT]

Where can I find what the codes mean?..mine reads D4 for the axle...

That means you have the 3.73 limited-slip.

 

[mcompton1973]

Yeah, D4 is what mine said also. Limited slip 3.73

 

[LC1500MB]

3.73 limited slip is what I figured but wasn't sure... Thanks for the info...

 

[V8Exploder]

that is the good one, keep it maintained well with Ford friction modifier and the proper fluid. The tag on the axle should even tell you the fluid weight to use, go by that tag. I've used redline synthetic with the ford friction modifier and mine still works well..... usually