gears.

[jarfly]

Okey simple qustion. My ring gears had 4:11 stamped on it. I wish I could go by the codes on this but my sticker was gone when I got the truck.

 

[4.0B2]

what's the question?

 

[jarfly]

opps. lol long night, What does the 4:11 mean? Is that my gear ratio?

 

[4.0B2]

Yeah should be.. I can't say for sure. But Idk why else it would say it on the ring gear

 

[scotts90ranger]

that's probably a time stamp, if you spin the ring gear around you will see several things stamped on it. Of the things on there are two numbers separated by a space those are the tooth count for the ring and pinion, divide the big by the small and you get the ratio. The ratio itself is not stamped on the ring, pulling the pinion out of my D35 I've found it engraved on the pinion shaft but that's hard to see from the outside

For the record the available stock gear ratio's are:

for the 7.5" axle:
3.08, 3.45, 3.73, 4.10

For the 8.8" axle:
3.27, 3.55, 3.73, 4.10

 

[4.0B2]

Ive never gone by stamps on one so idk. I've always counted. If in doubt.

 

[jarfly]

Yea I did't think ford had a 4:11 gear. It has been a wile since I pulled the stump out. Looks like i'll pull the place off the rear to see what it is. NO WAY am i goin thro the trouble of pullin the frount stump to see what gears it has.

 

[scotts90ranger]

I believe it's 4.11 in the 9" and D44.

The tooth count should be printed on the ring gear, you should be able to see it if you take the cover off. If you can't find the count printed count the teeth on the ring and pinion.

 

[4x4junkie]

IIRC, Ford stamps the actual ratio itself on the gears ("3.73", etc.).

Dana I know uses the tooth-count numbers ("41-11", etc.).

 

[scotts90ranger]

just checked a D35 and 8.8 ring gear I have in the garage and they're both tooth counts, 36 11 on the 8.8 (3.27:1) and 39 11 on the D35 (3.55:1) but there's a whole bunch of numbers punched on them, the 8.8 was right beside the Ford emblem, D35 was at the start of the numbers

 

[Hagan]

You don't need to pull the diff cover off to know what ratio you have. Just turn the tire and count the turns of how many times the tire goes around to one rotation of the driveshaft. Easier than pulling the diff cover unless you just like to be difficult?

 

[scotts90ranger]

there's a few other ways too, turning the tire isn't quite as reliable since the side gears and spider gears have different tooth counts.

 

[4x4junkie]

Side/spider gear tooth counts shouldn't matter.

Unless there's an actual mechanical-locking diff in there (would be a non-stock item if so), all you need to do is jack ONE tire up and then give that tire exactly TWO complete rotations while carefully counting the driveshaft rotations (marking the yoke or flange makes this easier).
3½ rotations = 3.45 or 3.55 (depending if 7.5" or 8.8"), 3¾ turns = 3.73, 4.1 turns = 4.10 and so on.