I was wandering about axles in my 83 Ford f150.. The truck I know does not have a 9" rear end in I believe it has an 8.8 with 3.08 gears.... My question is I wanna put in a 9" axle from my 82.. Is the front the same as the 3.08 rear.. Or similar..

 

The front is a Dana 44TTB, but yes, the gear ratios will be the same (or possibly off a point or two). You can't use 4WD without BIG problems if the ratios don't match.

 

Here are the two ratios offered in a 83 f150 front axle according to car-part.

3.07 ratio
3.54 ratio

Here are the listed ratios in a 82 f150 rearend.

(removable carrier, 9" ring gear), 2.47 ratio
(removable carrier, 9" ring gear), 2.75 ratio
(removable carrier, 9" ring gear), 3.00 ratio
(removable carrier, 9" ring gear), 3.25 ratio
(removable carrier, 9" ring gear), 3.50 ratio
(removable carrier, 9" ring gear), 4.11 ratio

 

You can determine your rear axle ratios, both years, by using the certification label decoder on my web site: Certification Label - Gary's Garagemahal. Find the code on your label under "Axle", as shown on that page, and then click on the blue box and you will be taken to the Axle page (Axle Ratios - Gary's Garagemahal) where you can find the code and associated ratio.

 

Car part doesn't agree with Dana.

 

The front gears would be 3.07. You're out of luck finding a 9" ratio at 3.08. The next closest thing would be 3.54 fronts with 3.55 rears, which they make for the 9". I actually have an extra set of new ones here. You have to stay I think within 10% of ratios to work correctly, but I wouldn't run on dry roads with ratios that far apart. The front should be slightly taller so it has a "pulling" effect.

The 8.8 IS a good rear, you just have to know what needs to be done to them. The only things I don't like is the outer wheel bearings riding right on the axle shaft and no rear support on the pinion. But, with the 8.8, the pinion bearings are much farther apart than the 9", which is probably why they got away from the rear support bearing.

 

You need to have them a lot closer than 10%! Being 10% off of 3.55 would mean anywhere from 3.20 to 3.90. That ain't gonna fly. Generally you want them to match, but when you can't get an exact match it's not going to be noticeable if you're only off by 0.01 or 0.02. And you can almost always get that close.

As far as front being taller, that's not a bad thing because the front tires need to go farther around corners. Ideally you would have the front ratio taller in corner, but ideally you'd have them the same in a straight line. So having the front gears shorter than the rear would be less than ideal in all situations.