|Jason's 1987 SAS'd truck gets Nitro 529 gears/Harrop in a Marlin HP Diff Housing|
|(72 BIG pics loading)|
|AUGUST 19 2018|
|Jason's lives up in Oregon where they have a lot of the white stuff in the winter time.|
|It was time to upgrade the front to a bare High pinion 8" from Marlincrawler.com and install a set of Nitro 529 gears and Harrop electric locker.|
|Empty Marlin housing on the left...the Nitro V6 master kit.....the Harrop Elocker....529 Nitro gears and the solid collar/dual drilled flange.|
|They chamferred the circumference of the V6 wheel adjusters which was much needed.|
|Parts are unpacked and layed out. All looks to be here.|
|The big inner pinion race is tapped in.....360 degree support, of course.|
|Same with the small outer race.|
|Will start with a .076" pinion shim.|
|The pinion loading station.|
| Tighten the pinion nut til the estimated preload is somewheres in the neighborhood of 10~20 ft/lb.|
This is only a pattern check so it's not critical.
| Now onto the other end. A quick check of the coil resistance of the electro-magnet.|
Measuring about 4 ohms.
|Surfaces were checked with a file and all was just fine.|
|75 ft/lb and blue loctite.|
|The new Koyo carrier bearings were a very nice tight fit onto the journals.|
|The top bearing cap has to slide on horizontally first and then the 2 long bolts go in.|
| Line the threads up...tighten the 2 bolts....and then thread the large wheel adjuster in.|
Then dial in some bearing preload and backlash.
|First paint check and way too deep. This is the drive side.|
|Teardown and now trying a much thinner .034"|
|Drive.....much better but over-shot just a little. This is slightly shallow now.|
| I did notice that the 529 ring gear was so thick that the teeth were almost hitting the tunnel groove |
so did some clearancing with the flapper wheel.
|Took about 20 seconds.....|
|A final look at the pinion paint shows that the comet tail is too deep into the root and that means to add more pinion shim.|
|So now to increase the thickness by .004" Now trying .038".|
|Coast....very nice indeed.|
|Final confirmation....pinion tooth....comet tail is starting to feather out to the center. That means to leave it alone and button it up :)|
|Now to set the solid collar in place....took about 7 tries on this Hi-pinion to get it right.|
|3 adjustments on pinion depth......|
|7 on the solid collar.|
| The 27 spline fanblade slinger will fit with a slight enlargement of the center hole.|
A Makita 1/4" die grinder and 3 minutes did the trick.
|Grease on the garter spring prevents the spring from popping off during the install process.|
|The Yukon brand seal appears to be a quality seal.|
|The new flange is next.|
|Anti-seize on the flat surface...not shown but also applied to the pinion threads.|
|All that anti-seize really helps in dialing in the pinion preload.|
|This side goes together like usual.|
|This side requires a little order of assembly as mentioned earlier.|
| The 2 long bolts are tightened and the wheel adjuster freely threads in.|
A quick final check of the locktab freeplay shows 1 mm.
|The wheel adjuster threads in smoothly.|
|Now the 4 bolts are torqued to the 70 ft/lb spec.|
| Bearing preload is set/measured at 6 in/lb (as measured from the pinion flange end). |
Backlash is recorded on every other tooth for 20 measurements.
|A small amount of rtv is applied to the rubber grommet.|
|The rubber grommet now pushes thru about 3 times easier ;)|
|10 inch/pounds with Loctite|
| 3.9 ohms of resistance. There is no Harrop spec on this but it seems to be a very common number.|
Ohms Law says that with 16 volts and 4 ohms that the amperage will be 4 amps.
So, the reality is, the Harrop only draws about 3.5 amps on a good day.
|This is my Sealed Lead Acid battery that has served me well for a number of years.|
|12 volts is applied to the 2 wires....no particular polarity.|
|The locker is not "active" until the 3 pins start to recess into the holes....the driveshaft has to turn a small amount.|
|The ring gear has to turn a small amount..... causing the pins to recess in as shown.|
|Locker fully engaged.|
|Additional turning of the ring gear causes the grey ramp ring to move with the pin.|
|Now remove the 12 volts.............|
| ...and the ramp ring snaps back into place due to the strong internal spring on the other side of the pin. |
Locker is now unlocked.
|Basic specs are inscribed.|
|This is the harness.|
|The recorded notes.|
|Sure is a pretty High pinion 529 Harrop 3rd|