Moment of Truth

This project reached an important milestone yesterday. It was the time to see whether i'll have a functioning brand new LSD inside the RT182 Corona axle or just end up with US$1,000 worth of Cusco paper weight. Before we get to the main discussion, here's the latest situation under the hood.

That ugly strut bar you see there is custom made. I used 5mm iron strip plate and stacked two of them for the main bridge just to be sure on the strength. The strut mount uses only single layer. Cost me 10 bucks, not bad huh? Here's a view on the strut mount side.

Getting back to business, here's what kept me from doing the LSD conversion sooner.

It's unsurprisingly difficult finding LSD gear oil here in Lampung. I got those FK Pulse LSD Gear Oil in Jakarta. I'm pretty sure it's just that i haven't looked for it hard enough as with all those off road SUVs and 4-by-4s i see roaming everyday here, there's bound to be a local shop that sells LSD oils for those vehicles.

The Cusco LSD i have is the RS-type and set to 2-way although i can set it to 1.5-way whenever i feel like it later. Here's the 2-way cam ring gear profile, you can see the center pin here.

and here's the 1.5-way profile.

LSD conversion is not something to be done by many of us, me including. It's a long tedious process and could easily fill up the swear jar with 50 bucks worth of small changes if done by inexperienced individual. First you need to take off the drum brakes and pull both axles out which probably have locked themselves frozen to the center diff after years of no maintenance.

Then you unbolt the center diff from the axle housing, after you drain the oil.

With the pumpkin out and the ring gear disassembled, i can finally calculate my final gear ratio directly. Here i count 11 teeth pinion.

and here's a stamp on the ring gear telling me that it's 43 teeth.

So, my final gear is 43:11 = 3.909 after all. A bit disappointed that i was right and it wasn't at least 4.1 but 3.909 should do just fine.

Next, transfer the bearings to the new LSD piece and bolt up the ring gear. You should always use a cross-pattern when fastening the ring gear bolts. In fact, always use cross-pattern anytime you can. It's just good practice. Oh if you have the retained plates for the ring gear bolts from the old diff, you can throw them away as they can't be used on Cusco's LSD. Use some thread-locks just to be safe. Why didn't i change the bearings? Well, i should have honestly but the old ones should be good for another year at least.

The mechanic fastened the bolts to 9 kg/mm using this big-ass torque wrench.

After that comes the hard part of adjusting the bearings and lash so that the pinion sits perfectly to the ring gear, preventing that dreadful whining sound.

Obligatory baller pic.

Once done, reassemble everything back. Don't forget to fill up the oil. You'll be pouring at least 1.5 liters in before it overflows from the fill hole.

Don't get too excited yet and skid like there's no tomorrow when it's done. It's advised that you do the boring figure-8 break in procedure for at least 30 minutes. It's no fun, i can tell you that. What you do is basically you find an empty space like a parking lot and do a figure-8 a few times. You'll want to accelerate in first gear on the straight part and push the clutch down when you turn as narrow as possible. Below image from Kaaz website should be clear enough.

As i said, i was pretty relieved to see that everything went smooth on the conversion. All those hours spent researching on the internet has really paid off. Everything that could go wrong, didn't. As John "Hannibal" Smith would say, "I love it when a plan comes together!"