Installed a Yukon DuraGrip with 4.10's to replace the open diff and 3.42's. Getting the proper carrier preload and backlash I pulled and reinstalled the carrier eight times. I was just within specs at .010 backlash (.006 to .010) but wanted it a bit tighter. The next try was a little tight at .004 then the last test fit came to .008 backlash exactly what I wanted.

The pattern looked good with a .034 pinion shim (oem shim was .033) so I didn't have to re-shim the pinion and start over. The crush sleeve eliminator kit took three tries .027 shim no pinion preload, .024 shim to much preload, and last the .025 shim came out to 18 in/lbs preload at the tight end of the 14 to 19 spec.

Hooked up HP Tuners and changed the settings in the Tire/Gear Wizard to adjust the speedo for the new gear ratio and to automatically scale the transmission parameters. During the test drive I heard no gear noise and noticed the truck pulled the hills on the road effortlessly where with the 3.42's I'd have to open the throttle more to keep the same highway speed. The camshaft is closer to the RPM range, you know the sound and feel where she wants to pull really hard! I wanted to get a little rowdy but I'm just starting the 500 mile gear break in and you're supposed to stay under 60 mph the first 100 miles.






Pressing on carrier bearings plus installing the ring gear and torquing the bolts



Backlash .008



Drive side pattern



Coast side pattern



The factory grease used to install the yoke had turned to glue after 19 years and was tough to drive off the pinion splines. I soaked it overnight in lacquer thinner to remove.

I've felt a little uncomfortable not doing the trunion upgrade during the build. Now I can sleep easier not having nightmares of needle bearings dancing around in the oil pan. I went with the brass bushings after researching and finding out the Comp, BTR and all of the caged needle kits have abnormal wear patterns on the bottom of the trunions.

Abnormal trunion wear.



I went with the Smith Brothers kit. It's packaged very well and came with two extra snap rings. Not a bad deal for $140 shipped (ebay). I ordered on a Wednesday and it was delivered the next day with standard shipping!



Tear down happy to see no stray needles





The 20 Ton Harbor Freight easily dismantled the old trunions. I used just my thumb in the bottle jack to lessen the power and to have a better tactile feel.



Pressing the bushings in the rockers.



I had to bust out my lighted magnifying glass to better see the clips and the tiny holes for the snap ring pliers. Getting old has a few draw backs... like seeing small objects... it's better than NOT getting old!



First two!



All pressed in ready to reassemble!



Installed and torqued to 22 ft/lbs



Valve covers back on and plugs & wires back in.



All finished