It turned into a long day, but by about 2:00 AM or so, the t-case brakes & drivelines were removed, the Axletechs were out, & the new hybrid axles were bolted in,
While I am swapping in the new axles, I am also upgrading all for the link mounting hardware from grade 8 bolt, to L9 fasteners,
With the new axles in place it was time to start sorting out all the needed changes, the biggest ones being brakes & drivelines,
If you go way back in the build, you can see I had both rotors & calipers for the brakes mounted at the t-case/drop box, while I still feel this was a clean setup, it actually made it a PIA to do some some things, like t-case or transmission removal, combine that with the fact the MTRA rule book states at least one brake has to be mounted at the axle, I opted to move both brakes to the pinions,
In some way this was going to be very simple, like plumbing, I had already run all stainless #3 lines down the link bars for actuating the Axletech air lockers, there are no air lockers in my now 21-145 diffs, so all of that plumbing can be repurposed.
The rotors & hats were designed to work with the rockwell style 4 bolt flange, which is what I bought for the 21-145 pinions, so it took very little machine work to move them from the t-case flange right over to the pinion flange,
And then the pinion in the 21-145 had a bolt on bearing assembly, similar to a ord 9" or a 14 bolt. so building a bolt on caliper mount was the cleanest easiest option,
I believe I had mentioned last week, while the rear 3rd/chunk was apart, I got precise measurements & drew up a very nice DXF pic/file of this pinion carrier/bearing assembly, & since I already had the DXF of the t-case caliper mount, I was able to merge the two & draw up a new caliper mount patter that should work perfect using all the parts I already had, (rotors, & calipers) I just needed to fab the mount,
My original plan was to plasma-cam a blank out of 1/2 plate, then set it up in the Bridgeport to drill all the mounting holes in the proper location, then for the caliper mounting bosses, I would drill/ream a "precision" .750 hole each, that way I could build standoffs out of something like 1.25" round stock, & machine a press fit register on the end to fit the .750 locating hole, I could adjust the length of those standoffs to position the depth of the caliper before pressing them into the 1/2" mounting plate, & TIG welding the front & back,
Really strait forward & pretty simple,,,,,,
Then I decided to build them out of billet aluminum instead.
Luckily My Dad had a couple 6"x 6" blocks of 1.5" thick 6061 aluminum he had for another project, so I grabbed those up & figured I'd see what this Shapeoko router table would do.
I actually spent a good bit of the day drawing this part up, creating the 2D DXF in plasma-cam was simple, but getting it into a 3D tool path was a bit more work,
I ended up drawing different stages of the part in Plasma Cam (I'm just more comfortable operating that program) then importing those files into Carbide Create (design software for the Shapeoko)
In short, I drew & imported the files in layers, each layer being a tool path with it's own depth of cut,
I could have fabbed the steel mounts in less time than I had creating the CC tool/cut file.
But eventually I got a block of aluminum on the machine & started making chips.
It takes a while to do this much cutting, but once you have everything working right, & if you can pull yourself away from just watching the machine, a guy can go do other things & just let this machine make a mess.
The first mount took a while mostly cause I I wash machining the part out one path or layer at a time, watching & making sure I had the tool file correct, (even a little CNC machine don't care, if you tell it to do something, it does it, right wrong, & if it's wrong, it's bad!
I only had two minor "crashes" both were cause by me messing with **** I should have left alone,
Even on the first part, during long duration tool paths, I would work on other stuff, like the rotor adapters that needed minor machine work to fit the pinion flanges,
Once the first one was done & fitment confirmed, the second block was setup on the table, & the machine pretty much turned loose to do it's thing, the only time I messed with it was when it stopped running for a tool change,
With a finished part in hand I was able to get to work on the rear brakes.
Pulling the pinion carrier/bearing assembly last week to get exsact measurements paid off big for this part of the project.
With the caliper mount bolted in place, the pinion flange, rotor, & rotor adapter could be installed, & the caliper bolted on.
The router table took about 4 hours to cut out each bracket, so even after getting the first setup installed, I was still waiting for the second part, But with a pinion flange installed I could get to work on drive lines.
The drive lines out for the truck were 1550 series attaching to the t-case using the 4 bolt Rockwell style flange, that will remain the same, however, at the Axletech end, they were built using the 8.5c winged style U-jount that bolts directly to the Axletech pinion. So I needed to change out the 8.5c fixed yoke, for a 1550 series one.
I knew this was going to be the case, so a couple months ago I bought a pair of Spicer 1550 weld yokes that would fit the current drive line tube size,
what I didn't know for sure was if the original drive lines were going to be long enough to just change out the weld yokes, or if I was going to have to re-tube them, so I bought a stick of 3.5"x.134 wall drivelines tube as well.
Lucky for me, the amount of tube cut to remove the 8.5c yoke, plus about a 1/2" was perfect to install the 1550 yoke & end up with the proper length,
By the time the second caliper mount was done, so was the rear drive line,
I finished up Thursday & headed home for a nap a little after 3:00 AM (Friday!)
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