Rear and front diff change???

[hoodup]

I have a 3/4ton SWB with I believe to be 4:10 gears. I'm thinking about changing to 3:73 Has this been done by anyone on the site? Is it really involved?

Truck as 35''x12.5''x16.5'' wheel tire set up and a 4 speed muncie

[Mudder]

With 35's I myself would rather have the 4.10's. You would have to change the carrier and it is quiet envolved. If it's not done right you can destroy them real fast. You will need some measuring tools. I have replaced things in mine but have never "set gears up". I have seen it done and that's why I have never done it.

If you wanna try it there are a lot of guys here that can and have done it that maybe can get ya through it.

[LONGHAIR]

I agree with Mudder 100%. This is very involved....and you already have the more appropriate gear anyway.

[special-K]

What rear do you have?14-bolt?Most guys just buy used rears for what the parts to change would cost...done deal.What trans?4spd or auto?A manual would be ok with a taller gear.I`ve run 3.08s with 33s and a 4spd.It was fine and there`s always granny.With an auto you may use more fuel.Figure you have right about 3.73 right now with 35s on 4.10 axles.

[Mudder]

I have ran 35's for close to 30 years with 3.08's, 3.73's and now 4.10's. Always auto. It was a slug with the 3.08's, period. The 3.73's were a big improvement but not as satifying as the 4.10's. If you are going to do any off roading at all I think you will want to stay with the lower gears. If you are just going to be doing hwy you may be able to get by with the 3.73's.

[b454rat]

My old truck had 4.10s with 35s and a 4-speed, was the perfect all around gear. Could still fly down the highway, great around town, 1 st gear and t-case in low made for good wheeling....

[hoodup]

It’s funny, after I posted this I got to thinking about my question. This truck is for pulling pushing and climbing. It’s an everyday driver as well as a hunting and fishing set up. Around town its great and I can get down the interstate doing 65 at 2500 rpm. And I never thought about the ratio with the rear end and the tires making it a little taller gear. You guys gave excellent feedback, and there are no plans for the change in gears. I would hate my self for doing it. If it isn’t broke don’t fix it.

It is a 14 bolt rear with Dana 44 front and I think Dana 60 in the rear (not sure yet) with a four speed manual setup. I only need to use 1st gear in the mountains.

So with the 35'' tires what is the gearing with 4:10? And how can I tell how fast am I really going? Am I about 10mph faster?

[LONGHAIR]

It depends upon what tire size your speedometer was calibrated to in the first place. The easiest way to figure your speed to to drive next to a "known correct" car and see where your speedometer reads.

[hoodup]

Thanks! I see you have a link to the rules page, Did I miss post something??? Or is that on all of your replies?

[jason65]

It's a signature. Like what you have.
Nice truck dude. Thats how I'm planning my 64 to look, stance wise.

[hoodup]

Thanks Jason! Yeah its a fun truck, It looks a little different than the pic. Need to post some new pics of the in undder and outer.