Going For The 4•5•6 - Gears In

So lets take a look at some pictures first. Here is the rear axle with the cover off and the gears+locker in. You can see the Auburn Ected electronic locker installed with its wiring leads.

Ryan and his team, the great mechanics and fabricators over at National 4WD, said that the parts went into the housing with no significant problems or modifications. This goes for the front housing as well (see earlier post pictures of the tiny housing). The only thing he had to do was to hammer the axles in a bit more than usual so that they would reach the locker's splines.

Unfortunately I don't have any pictures of open front housing. And even though the 7.2 parts went in relatively without a hitch, I have to warn any potential gear swappers, that changing gears in the front housing is a very complicated, time consuming, and potentially expensive endeavour!

Here's a direct quote from Ryan:
What a job to get the front diff out I don't want to have to do it any time soon again!!!!!

The situation is that to swap the gears, you have to remove the housing. To remove the housing you have to drop the oil pan. To drop the oil pan, you have to remove the steering rack, the anti-sway bar, etc.

Just so everybody knows, the GM labor guide to drop and re-install the oil pan is listed at 10 hours!

Again, the good part is that the Yukon Gear parts and install kit all fit nicely into the housing. One exception is the side seals that come with the kit, they don't work with our unit so you have to get the GM seals instead.

But at the end of the day, all the 4.56 parts were correct and fit into the housings properly.

So for the record, a 2003 front housing (which I got from the auto yard) successfully bolted up to my 2006 Trailblazer. The rear housing has a little story to it.