As you guys know I’m about to dive into a gear swap. I have been planning to swap the entire axles in but at this point for sake of time and being I have professional mechanics by my side I’m going to do just the internals. My question is that I’m not 100% sure that the axles I got are 3:54 ratio. They came out of a 98.5 5 speed. Did they ever put 4:10s in a 5 speed? Also I’m concerned that the 3:54s are not LS differentials and is they’re a way to convert it to LSD without need for a 600$ locker? Can you just buy a used 3:54 carrier? 

16 hours ago, Dieselfuture said:

My instant mpg meter on qwad just drops like a rock if I'm above 70 and it's very accurate now that I got it dialed in. It seems im constantly trying to build boost even going slight down hill. It could still be in my tuning, but don't think so. I'm close to 20 timing at 70mph summer was closer to 22 and I played with it too to see if there is much change, not really, which is wired. I need to drive it more and play with settings,  I had it working good right before it cooled off and now chasing ghost. I'm not too worried as I know it'll come around. I didn't just gave up my 285s to have crappier mpgs at 75 with 265 so I'm determined to figure it out, just taking my time. 

Just running a Comp on mine so i dont get to mess with the timing and such. My truck seems to get good mileage at 70 to 75. Thats 2000 to 2200 rpm. Maybe just its sweet spot. Let me get over 75 and it starts falling off. Also this is on a pure interstate run. No mixed driving at all. I also never got this mileage on the stock injectors. It started after running RV 275s and the current DAP 50s that are in it now.

3 hours ago, Blueox01 said:

True but Marcus2000Monster was replacing (from my understanding)a complete Differential from 4.10 to 3.54, that was supposed a swap, so it was out of the truck, my comment was why open differential to count teeth vs rotating pinion.

Did you replace the whole diff? or just the ring/pinion?

All the guts.

One issue I’ve ran into since the swap is my brake pedal will intermittently get hard upon applying the brakes. 

On 12/20/2018 at 8:31 AM, Mopar1973Man said:

 

Don't turn tight! It puts a huge amount of stress on the 4WD and breaks stuff. 4WD is meant to be used while traveling straight mostly or slick conditions where the tires can slip. When locked in 4WD and on hard pack is really rough on the transfer case. 

 

I learned that my front and rear axles even when the trucks up in the air doesn't lock front to back. Rears were on the ground in 4wd and the fronts still spun?

 

On 12/20/2018 at 8:55 AM, Marcus2000monster said:

Eventually id like to install the CAD switch. 

 

I wish I kept the CAD switch. I like the pull cable, but its a real peace of work to get it into 4WD, usually involves putting the truck R-N-D-N-R something like that.

 

1 hour ago, pepsi71ocean said:

I wish I kept the CAD switch. I like the pull cable, but its a real peace of work to get it into 4WD, usually involves putting the truck R-N-D-N-R something like that.

 

This is why I didn't use a cable to control the CAD.  Instead, I picked up a GM HVAC vacuum control unit from a wrecking yard for two dollars.  I figured out which ports would work and I plugged the rest and I use that vacuum switch to lock just the front axle. 

 

Just rotate the knob one click and start moving the truck and the CAD locks in - reverse the procedure and the CAD unlocks.  No fuss, and It's been operating that way since the truck was new.

 

- John