I want to run the biggest tire possible with out swapping the axles. I have an 89 f250 5.8w 3.55 gears d50 in the front and 10.25 in the rear. Can I up grade the gears without switching the entire axle?

 

Not a problem. Your front axle is pretty solid up to 36's or so without a locker in it and rear axle is solid up to 38's or so with a locker. You can also go as low as 5.38 in either axle. Below is a link for a tire size/axle ratio calculator if you do not have one.

Click Here

 

So if I wanted 4.56 or 4.88 I would't have to swith the entire axle? If not what excatly would I have to buy and where is a good place to get it? Thanks for the quick reply

 

Correct, you can keep current axles. Here is a few links for parts

Click Here

or

Click Here

 

Well that sure makes it seem alot easier. So all I have to buy is a Ring and Pinion kit for the ratio I want? Is the easy to install?

 

if you take your time and do it right and dont cut cornors yes. if you have no experiance with work like this at all it really isnt recomended. you need special tools to set it up right. im sure someone else will check in with better info on it.

 

I don't know what the carrier split is for these axles since I don't work with the 10.25 or the D50 but investigate that too. Most axles will have 2 carrier options and you can only change your gear ratio so far without having to change carriers too. If you do need to it's no big deal, an open carrier is pretty cheap. The 10.25 will handle pretty much any tire you'd want to throw at it but that D50 is pretty delicate. Be careful how big you go. I'd say SnoMan's advice of keeping it limited to 36" is dead on. Too big and you'll start snapping axle shafts left and right.

Setting up gears isn't really "hard" but it can be tedious and must be precise or you'll burn them up. You need calipers, a dial indicator, inch/lb torque wrench, sometimes a case spreader and special bearing tools. Because of this it's a job that most people will prefer to take it to a shop for.

 

the ford axles dont have a case split any gear will work on the carrier you have now. for the dana 50 it is 4.10 and numerically lower.

 

The only reason a D50 does not have a case split is because it only supports from a 3.54 to a 5.38 unlike the D44 which supports from a 3.07 to a 5.89 "Ford D44's and D60's have case splits (except for reverse rotation 44 which uses basically the same gear as a D50 does)

 

Thanks again for the quick replys. I'll probally stick with 36's. If I wanted to go bigger. How much do you think an avarage shop would charge to change the gears?

 

that thing will be a dog with 36s and 3.55s. im running 3.50s and 32s and hate it. i have no acceleration off the line. with the big tires and high gears your truck will feel gutless. i think what The SnoMan was refering to was the strength of the axle. for the 36 you would really want a gear change to atleast 4.11 probalby 4.56.

 

Expect to pay $300-$500 per axle for the labor on a gear change. This is not including the cost of the gears or bearings if needed.

 

Dam that is more then I expected. I'll probally get a book, so I can do it my self. I've done very little axle work. I'm not good with spefic names of parts but here is a picture I found on the net. http://www.industryfigure.com/berkeley/Jeep/wrenching/dana35cclip3.jpg I replaced the four small gears inside that box shape thing. Basically what I'm asking is how hard is it actually to do this.

 

Those are usually referred to as spider gears (yeah, real technical name ). They are easy to replace. The ring and pinion is a whole 'nother story not so much in the fact that it's difficult but in the fact that you have to set it to exact tolerances. Off by a few thousandths and you can destroy a ring gear in no time. As I mentioned earlier, it's not really "hard" so to speak, you just have to know what you're doing, have the right tools and know how to read them. A first timer can get it done if they have a lot of patience and the proper tools. Remember, shop fees are by the hour. The figures I gave you are indicative of the amount of time it takes an experienced mechanic to disassemble the axle, set up the gears and then reassemble. Figure at least double the time for someone who hasn't done it before.

FWIW I was going to take my axles to a shop to have them done and decided I'd be better to invest in the tools and learn it myself. Now I'm quite comfortable with it and wouldn't hesitate at regearing an axle but it took me a while to get it all figured out. I would snap pictures of my gear patterns and send them to a friend for review to double check my work. Once I got that out of the way there was nothing on the truck that I couldn't tackle myself. It's nice not to have to pay a shop to do these things.