My Axles Are Back!

Hallelujah! After two months of waiting, I finally have my middle and back axles back in my grubby little paws and can take them to R&W!

You’ll remember that in mid-August I took the two axles to Tucson Differential with a request that the center sections be swapped. This entailed a lot of steps:

  1. Disassemble both of the axles so that the center sections could be removed.
  2. Disassemble the low-pinion-and-“Magic Box” combination.
  3. Machine the front pinion support / housing on the high-pinion center section so it would accept the “Magic Box.”
  4. Drill new mounting holes in the “Magic Box” so that it could be clocked over to a more-horizontal orientation; in turn, this would mean that the upper end (with the input and output yokes) wouldn’t stick up as high as it might have otherwise and that it would be more in line with the transfer case yoke.
  5. Weld the original mounting holes to prevent leakage from the “Magic Box.”

When I took the axles to Bill, he told me that it would be about 2 1/2 weeks before he could work on them. I visited him after about 3 weeks and he had just disassembled them. We had originally thought that he could swap the pinion supports, but that turned out to be impossible as the high-pinion support has extra galleys inside to ensure that the bearings get oiled properly. Those galleys interfered with the ring gear in the low-pinion center section. Also, the low-pinion support didn’t have any corresponding oil galleys, and it wasn’t practical to reinvent them, so the result was that the high-pinion support was itself machined to provide a clean, smooth mounting surface for the “Magic Box.”

The back axle was ready in short order, as it only had to be disassembled and reassembled with the low-pinion center section. I opted not to take delivery of it, though, until the middle axle was ready. Because Tucson Differential doesn’t have the ability to machine or weld aluminum, that work had to be subcontracted – and then both Bill and I had to wait on the subcontractor’s schedule!

This week, it all finally came together. The subcontractor returned the modified “Magic Box” to Bill, Bill put everything together – again, and I collected them two days ago (Thursday, 10/8). Here are some photos I took.

Back axle - formerly high-pinion; now low-pinion.

Back axle – formerly high-pinion; now low-pinion.

Middle axle - "Magic Box" is higher off the ground and more horizontal than before.

Middle axle – “Magic Box” is higher off the ground and more horizontal than before.

Middle axle - before changes. "Magic Box" is more vertical and sits lower on the center section.

Middle axle – before changes. “Magic Box” is more vertical and sits lower on the center section.

You can see clearly here that the "Magic Box" no longer hangs below the axlehousing.

You can see clearly here that the “Magic Box” no longer hangs below the axlehousing. This is a good thing.

We ultimately couldn’t lay the “Magic Box” over as flat as we wanted to, because of interference issues between one of the center gear’s bearings in the Box and the bolts that hold the Box to the center section. But my guesstimate is that the Box is now at about a 25-to-30-degree angle instead of its former 45 degrees. And that’s going to be fine, not least because it now holds more oil.

There will probably have to be some changes made to the frame now, because the upper end of the Box is higher than it used to be. But that’s a small price to pay for the vulnerability reduction to the Box!

I’ll be taking the axles to R&W on Monday. Let’s hope this is the last change we need to make to the axles, and that the frame can be completed and the bodywork begun!

Side note: I am very pleased with the quality of the work done by Tucson Differential and recommend their services without reservation.

Categories: axle, drivetrain, JeepMonster, tandem axle | Tags: , , , , | Leave a comment

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