Started this weekend with the front differential/axle unit. Removed the skid plates, lifted it up on jack stands in the front, removed the tires. Set a floor jack under each lower ball joint for peace of mind. Unbolted the front CV and drive shaft and used a transmission jack to lower the front drive unit down. It's a R200 that was used for decades as the rear differential in Z cars. The First Gen Xterras and pathfinders really have a super stout drive train. The transmission jack made it much easier to lower out of there. I cleaned up the outside to try to keep the threat of grit getting everywhere, and popped the cap and drained it, and moved it to my bench, where I removed the housing axles and bearing caps and pulled out the carrier.
I went ahead and put it in a vise and removed the old 4.6 ring and put on the 5.13 ring, though that required a trip to get some red threadlock, and some research to find the right bolt torque. The front drive doesn't get much use and the bearings feel perfectly smooth so I am going to keep the originals in place. I bagged that up for reinstall.
While I was under the X, I found a loose exhaust bolt at the header flange, and decided to drop out the exhaust section with the cat I had fabbed up a couple years ago to weld it properly. I had clamped it before but was never satisfied with the fit and it had some leaks, so I pulled that out and welded it all up and removed the clamps, then put it back. No more chugging.
I can also see I have a rear main seal leak, but dropping the transmission without a lift is probably beyond my abilities, so I will pay someone to do that at some point. Might tolerate it until the next clutch replacement.
Back to the front unit, I had to fab a tool to bolt to the pinion flange so I could loosen the pinion nut, and I ended up making a pretty nice little lever that should fit the rear flange also and between that and a 6 foot cheater pipe on my 1/2 wratchet, the pinion nut had no chance. I did have to make a trip to harbor freight for a 3 arm puller as the 2 arm one kept just going cockeyed, but I popped the flange off and decided I was done for the day.
Next up is pulling the pinion and removing the race and shim and swapping the new pinion in. I may use new bearings but the factory ones still seem pretty good as well. I'll finally get to use the 12ton press!
My biggest challenge is going to be setting the pinion depth right in as few tries as possible. I don't have any type of depth gauge, so I can only go off contact pattern, but that requires getting into ballpark range to start, so I am hoping the existing shims will be s tolerable starting point.
I went ahead and put it in a vise and removed the old 4.6 ring and put on the 5.13 ring, though that required a trip to get some red threadlock, and some research to find the right bolt torque. The front drive doesn't get much use and the bearings feel perfectly smooth so I am going to keep the originals in place. I bagged that up for reinstall.
While I was under the X, I found a loose exhaust bolt at the header flange, and decided to drop out the exhaust section with the cat I had fabbed up a couple years ago to weld it properly. I had clamped it before but was never satisfied with the fit and it had some leaks, so I pulled that out and welded it all up and removed the clamps, then put it back. No more chugging.
I can also see I have a rear main seal leak, but dropping the transmission without a lift is probably beyond my abilities, so I will pay someone to do that at some point. Might tolerate it until the next clutch replacement.
Back to the front unit, I had to fab a tool to bolt to the pinion flange so I could loosen the pinion nut, and I ended up making a pretty nice little lever that should fit the rear flange also and between that and a 6 foot cheater pipe on my 1/2 wratchet, the pinion nut had no chance. I did have to make a trip to harbor freight for a 3 arm puller as the 2 arm one kept just going cockeyed, but I popped the flange off and decided I was done for the day.
Next up is pulling the pinion and removing the race and shim and swapping the new pinion in. I may use new bearings but the factory ones still seem pretty good as well. I'll finally get to use the 12ton press!
My biggest challenge is going to be setting the pinion depth right in as few tries as possible. I don't have any type of depth gauge, so I can only go off contact pattern, but that requires getting into ballpark range to start, so I am hoping the existing shims will be s tolerable starting point.