4.56 gears and 35" tires will perform exactly the same as stock gears with stock tires as far as load on gears tranny motor (whole drivetrain actually) even your speedo will work right again... thats what I have and I have great power...my mpg is only like 13mpg right now but I have 35" mudders and its cold here...that will effect things no matter what gears you have.. If you do in fact have 3.55 with 33 inch tires I imagine it will perform similiar to 33" and 4.10....4.10 are great for sizes up to 33.
35" 4.56 will perform the same as 4.10 and 33" tires..I dont know why so many people have issues grasping this as it comes up nearly every day. (I'm not talking about you since your new here)... If you search it you will find a nice chart here showing whats best with what to get closest to stock mpg and performance...

 

i'm answering this based on what i know about the chrysler 9.25, so if that doesn't apply to your dana 60, then ignore me. if you have an open diff, and all you need is a new set of side and spider gears, then replacing those is easy as pie. just slide the axles out, replace those gears, and put it back together again.

you don't have to remove the ring or pinion or bearings or spend any serious money at all. i'm not sure where you'd get the spiders and sides for cheap, but even new shouldn't be overly expensive. try Randy's or the other online diff sites.

edit... here you go. $115 for spider and side gears. you have to specify the spline count for the sides.
http://www.ringpinion.com/PartsList....fID=20&CatID=4

 

Ok I really don't have the money for one...but has anyone ever used those locking diffs that lock on demand by electromagnets or air power? I was reading up on them and I'm weighing my options. BTW, I've pretty much decided on going with the 4.56's. It was a very big reason why I bought the truck (because I was told it already had 4.56's)...so I figured I may as well make it right. I'm a little worried about going with an LSD compared to a locker. I like the fact that lockers are *******ly open during city driving, and only come into play when you really need them. BUT, it seem's like LSD's would be less prone to failure. So since I'm kind of going all out and doing new gears front and rear, I want to make sure I do it right with a good quality LSD or locker in the rear. I'm about to check out that Auburn LSD that 95RAM360 suggested. Thanks everyone. Oh, and by the way, who makes a good set of gears? There's this place called Drive Train Specialists that's really close to my house, and I've heard nothing but good about them. But, any other suggestions?

 

You do know you are looking at 800 for a arb a full time locker will set you back less. I just found out there is metal in my lsd so I'm getting 4.56 sooner than I wanted.

 

somebody on here had and OX locker in the front and the rear and thought a lot of it. its cable driven so its simple.

the Air locker is a little complicated and i think? it requires a constant air source to stay locked, which would really suck if you had a stick kick up and break an air line at an important moment.

i'm sure someone makes an electric but i don't know who.

yukon, richmond, precision, motive all seem well regarded. you likely get what you pay for, so don't scrimp on the parts and don't buy any cheap chinese junk for the rear end, since it cost so much to install it.

ask your installer for their recomendations. they're your experts.

 

I'll be doing the install myself, so I'm only looking at parts prices and maybe a case of beer to my fellow mechanics for some guidance (I'm a lead mechanic at a Mazda dealership...but most Mazda's don't have differentials like the one on my truck). A couple of guys on the ford side of our dealer should be able to lead me in the right direction and give me some pointers if I get lost during the installation. I found something called a Detroit Trac-loc (or something like that)...and I'm really interested in going that route. Now, the carrier alone is over 600, and I still need to buy rings and pinions front and rear, plus all the related hardware and crap. So I know I'm looking at a big chunk of change, but...this trac-loc system doesn't have clutches that wear out, and the reviews I've been reading sound pretty good. I'm going to call that Drive Train Specialists tomorrow and get a full quote on everything. I still need to make that damn tool to replace my axle seals, haha. I didn't know dodge didn't put dust seals near the ends of the axles...or my truck just has them missing? Is there any aftermarket dust seals available to help keep dirt and crap out the axle tubes? (front axle)

 

The true track is like a locker but its also like and lsd. Hard to explain. I guess you could say its a heavy duty lsd.

 

check riversidegear.com for outer "slinger".

 

Oh, my mistake. The rear diff I'm looking at is called a TrueTrac, not a trac-loc, sorry.

 

the true trac is known to many as a locker, but it is an LSD... i am putting front and rear True tracs on my D60s when i regear....

as for hte gears, just be glad we are helping you and go with the 4.56 gears, you will love your truck more when its done... as it is, i am going to be regearing my axles here in a few months because i am running 4.10's on 37's! great highway, but 0-60 in about 5- 6 mins.... and i get really bad milage around town cause the truck is working so hard.... but yea, do yoru 4.56 and then in my opinion, do the truetracs... they help in off highway stuff...

by the way, i am going to be regearing mine to either 5.13 or 5.38's cause im going from 37's to 42" boggers here soon..