Teeth on Rng Gear

[Navig8r]

OK, I'm tired of this 3.08 business! I see 3.73 ring and pinion sets on eBay going for around $100. This weekend I will be replacing the differential cover with a chrome one (fun, fun, fun when you inhabit a condo with no garage) and will be able to actually count the number of teeth on the ring gear.

The vehicle sticker says this old beast has a 3.08, per someone else's post a few months ago on the diff codes. But, I notice that the '93 XLT 2WD Auto and the '92 XLT 4WD Auto tend to display the same tachometer reading at identical speeds and on flat, dry roads...and on the same size tires (P235 Michelin).

It appears that the only way to KNOW is to count the ring gear teeth. My question is:

How many ring gear teeth SHOULD there be on a 3.08?

How many ring gear teeth SHOULD there be on a 3.73?

Inquiring mimes want to know...

 

[Campbell]

to figure out your ratio just divide the number of teeth on the ring by the number of teeth on the pinion. that is your ratio. Or you can do it the lazy mans way and do it by rotations. Lift the back of the explorer up and have someone turn the tire exactly once. If you mark the rear drive shaft, you can do a pretty good estimation of how many times the shaft will spin. It will either be 3.08 times (just bearly over 3 turns) or 3.73 times (almost 4 turns).