Harrops at both ends with Nitro 488 gears for Stu's 1997 LX450
(48 BIG pics loading)
JULY 5 2019

This is Stu's 1997 LX450. 488 gears and Harrops at both ends will be a BIG jump in performance.

Basic mods are the front bumper and a 2.5" lift.

A heavy box with Stu's rear 3rd in it has arrived.

The 3rd is mounted in the fixture. JustDifferentials.com sent this "gear package kit" to me in 4 days time.
It conveniently contains everything to do the front and rear gear installs....
both ring/pinions...both bearing kits....both solid collars....and the larger 29 spline pinion flange for the front.....

And, last but not least, the rear Harrop elocker sent directly to me from Australia.
I can't believe I get these things in only 3 days time to my doorstep!
God bless DHL.

All the good stuff is layed out for the rear install.

Both surfaces are checked with a coarse file and all checks out fine.

Ring went on perfect....not too tight and definitely not too loose. All 12 ring bolts were dropped in place
and everything was in perfect rotational alignment. I have a good eye for lining up the holes from years of practice.

Red loctite and 81 ft/lb.

Tapping the carrier bearings on......

This portion is now complete.

Took my best guess and will use .056" pinion shim for the 1st try.

Old races welded together works well for me. I see I scribed on it 12-29-13....almost 6 years ago.

Now onto the pinion end of things. Pressing the pinion out.

New inner race......

....100% tapped in all the way.

New smaller outer race also tapped in.

The pinion is now mounted and the nut tightened up just enough to offer about 10~15 inch/pounds of preload.

Install the diff carrier and tighten the wheel adjusters to get some bearing preload while watching the backlash.

Tooth is painted and the result is a very nice drive side pattern.....looks super.

Coast looks ok.

And the comet tail on the pinion tooth confirms that I do not want to go any deeper....to leave it alone.

Says here if I go any deeper then I will be in a "too deep" condition.


Just got lucky on the pinion shim so now can install the solid collar.
Many times, the collar plus shim tend to be very close to 2.135".

Got lucky again using .0455" as the shim. Hit it right on the money.

Now the Marlin seal designed for the 27 spline flanges can be tapped in.

The Marlin seal rides in a new virgin region about .200" below the usual groove on the flange.

Anti-seize reduces the friction......now I can tighten the nut with less of a hernia chance.

A smooth 10 inch/pounds of PPL. Of course, lots of fresh oil on both bearings and the seal was well oiled too.


Stu has not sent me the front 8" high pinion yet.....but when he does, I'll have the rest of his product ready
but I digress.

So, the pinion end is complete....I also drilled the 29/64" hole for the rubber grommet.
And now to put the diff carrier in.

I made sure that the stop tab freeplay on the Harrop tabs was 2 mm. Backlash was set to .007" minimum.
The preload of the carrier bearings was set to a solid 5 inch/pounds.

The resistance of the magnetic coil checked in at the usual 3.8 ohms.

RTV on the rubber plug helps seal and lubricate for the push-thru.


Now the 12 volt test.

12v is applied to the magnetic coil wires. It draws less than 4 amps.

With 12 volts applied the grey electro-magnetic ring on the right attracts and bonds the ramp ring to the left of it.

Now turn the pinion which turns the ring gear(and left case portion)
and the 3 pins are forced to move into the case as shown. Pass 12volt test.

Data is inscribed.

A snapshot of the assembly notes.