Determining Gear Ratio?

[Nate C]

Anyone know which of these I'm supposed to count to figure out my gear ratio?

This truck was originally a 2.5 manual 4 speed. I've heard these were 3.55's but I'd

like to verify. What do I do (math wise) when I have my counts?

 

[Eagle]

The part on the left (in the photo) is the ring gear. The smaller gears (in the photo) are the spider gears. They don't count. In front of them (hidden in the photo) is the pinion gear. You count the teeth on the ring rear and the pinion gear, then divide the ring gear by the pinion gear.

 

If you rotate the ring gear, you should see numbers stamped in the edge. Those are the tooth numbers, and if you perform the above exercise in arithmetic you'll have the ratio.

[glundblad]

The part on the left (in the photo) is the ring gear. The smaller gears (in the photo) are the spider gears. They don't count. In front of them (hidden in the photo) is the pinion gear. You count the teeth on the ring rear and the pinion gear, then divide the ring gear by the pinion gear.

 

If you rotate the ring gear, you should see numbers stamped in the edge. Those are the tooth numbers, and if you perform the above exercise in arithmetic you'll have the ratio.

 

Eagle,

 

You really rock. The info here and what you gave me in a previous post??? For your own sake, I hope you look this stuff up in an old book somewhere and that you don't keep this stuff stored in your head? :brows: Why don't you stop by my house sometime and swap out my 3.08 hears in my D44. It would be a great time. I will even buy you lunch. :yes:

[Sir Sam]

[jtdesigns]

:agree:

Divide the large number by the small number.. or spin the pinion and count how many times it turns a complete round and mark a line on the ring somewhere and make the ring turn once around... If it (the pinion) turns three times around then a lil past a half turn then its 3.55,, If it spins around a tad past 4 turns its a 4.10,, if it turns 3 times and 3/4 turns its a 3.73,, so on so forth...