Determining Rear End Ratio - L-112

on't have to pull the cover and drain the oil, the tooth count is on the head of the pinion, when the r&p are mated, the tooth count is etched into the pinion, along with some other numbers.

On the fords as well? I didn’t notice that on mine.

I never saw any numbers on the head of the pinion of my Ford 8.8, only on the tag attached to the cover.

Ok, I guess it is a bigger truck thing, I have seen it on various makes and models so thought it was more or less universal. I stand corrected. Sorry for any confusion.

Thank you everybody for your inputs.

I happened to have the cover on the rear end off - so I counted the teeth. Pinion Gear = 10, and Ring Gear = 41.
That gives me a 4.1:1 gear ratio - same ratio as when I counted the tire versus input shaft rotations.

VWJake: Thanks for returning me to my original plan of - get it driving, get a feel for it, and then make changes as required. A brake update is a "must do" in my book before I get it rolling down the road. The 8.8 already has discs (need refresh), and I already visited TSM for a front disc brake conversion kit (30 min drive from my house) - so, I'll have discs all the way around. I just need to work out what master to use with the original pedals.

Thanks again for everyone's input - appreciate your help!
Heinz

your 4 speed should be a 1.0 on the fourth gear. here is a rpm calculator http://spicerparts.com/calculators/tran ... calculator input your info to get you close to the rpms you want on the highway. summit racing has numerous ratios for the ford 8.8. I have 3.73 in mine with a turbo'd bd240, t98 and 31" tires and I'm gonna re-gear to 3.08 or 3.25 to drive the freeways here. I'm not gonna be pulling or hauling, so take that into account when figuring what you plan to achieve.