Magilla Gorilla: Full Body Workout

by in Magilla Gorilla, Steve

Because a video is worth a thousand pics:

I spent the better part of the day swapping my diffs – pumpkin for pumpkin. That is a BIG one man job! The JZX pumpkin makes the Nissan R200 housing seem like a tennis ball. Having now swapped both types solo…this was a BEAST! To jump to the punchline, it was a success. I emerged from under the car beating my chest yelling “I AM ALL THAT IS MAN!!!!!” Seriously, I was ecstatic to get the first front mount bolt started; at that point, I knew I had it. I got it in on the first try. All be it that try was a 30 minute wrestling match, but I never had to put the diff down to restart. PROUD.

I didn’t snap any pics of the removal or install since it is a well documented and incredibly straight forward process. Instead, after getting the old diff out, I spent a few minutes coming up with a possible fix for the rear diff’s nasty habit of puking gear oil out when it gets hot. My goal was threefold: help the breather breathe easier; keep the fluid in the diff; and keep outside contaminates out. Here’s what I came up with:

Diff breather mod - GO!

The damp oil is boil over residue on the old diff.

Pop the jiggle cap off and you're left with this open port.

Under the cap, you'll find a spring and solid rubber disk. I already cut the whole in it here.

The built up pressure pushes the solid rubber disk up over powering the spring pressure which then bleeds out from under the cap. My plan was to make a constant “bleed” by cutting a hole in the rubber disk. Pressure will constantly be bled at a slow rate. If more builds up, it will function as Toyota designed and lift the disk.

Cap reassembled (the spring is below the rubber disk in the cap).

Whole assembly back on the port.

Filed a bit off the bottom to help open the air way.

I filed off some of the lower edge of the cap to increase air flow and ease its exit route. Again, the whole idea is to be a preemptive strike to the relieve unavoidable pressure that builds up in the diff. (I then swapped this bleeder on to the new diff. I would have just called this practice had something gone awry.)

A side note, I noticed this two casting differences on the two diff covers. I don’t know if they mean anything, but I thought someone out there may know. My guess is it’s an indication of open or torsen differential since those are the two options. Or, it’s just a production run marker.

Old diff's cast number across the top of the rear cover.

New diff's cast number across the top of the rear cover.

I am sore, tired, and going to bed!