Removing Miata Rear Differential

If I remove the rear diff from the Miata, do I need to pull the axles out or can I just disconnect at the diff flange? I am reluctant to turn this parts car into a stationary pile, and for the $100 offered for the diff, I would pass if this is going to be an ordeal.

The other question is the PPF that joins the diff to the gearbox. There seems to be a trick to getting the front bolt out. The lower sleeve I get. The top one seems to be more elusive as to how to remove it. Any first hand experience would help.

Thanks

You can just unbolt them. Popping them out is not a big deal, but then the diff will want to leak.

There's a sleeve inside that front bolt that's been pushed up. Easy option: thread the bolt in partway and whack it with a hammer. That'll pop the pressed-in threaded insert out of the top of the PPF and you can disassemble from there. Alternately, remove the spacer from the bottom of the diff and then push the PPF up.

Thanks Keith. I guess it will all make sense when I get under.

As to the other question, how much dis assembly of the uprights or hubs needs to happen to get the diff out?

It depends a bit on the year. 1.6 Miatas have a different diff than the 1.8s do.

Removing the PPF from the diff is basically the same regardless of year.

If you have two-piece halfshafts (1995 or older), then you don't need to pull halfshaft out of the uprights to get the diff out. I'm not sure what your end goal is here so I can't give better info.

Someone wants the diff for $100. If it is going to require pulling the axles, it might not be worth the effort to sell it until later in the project when it has to all come apart (months from now) I do not know about the miata axles, but most that I have messed with require serious hydraulic presses to pull apart.

Would a sawzall cut through the axles I wonder?

It would but there isn't any point. If it's a 1.8 with the pressed in axles they will pop out pretty easily using a flat head screwdriver on either side of the axle and tapping them in until the spring clip inside the diff clears its detent point. $100 for a diff is pretty cheap, if the axles are still good you can sell them as well, no point destroying money.

So much easier to pop the axles out than destroy them! Note that the 1.6 VLSD axles are different than the 1.6 open axles, so your customer might need them.

What's the future plan for the rear end?

This is a 1991 non VLSD car. So the diff is not that valuable.

The plan here is to liberate the rear clip from a Miata and slide it under a Volvo. So, while I do not need the differential in place, I do need the rear suspension to be assembled with wheels and tires on the chassis jig.

If pulling the rear end out is going to take me half a day, and another half a day to cobble the rear suspension back into rolling status, then $100 is not worth it; I will wait until I am ready to blow the rear end apart and install the Boss Frog rear diff kit for the 8.8.

It shouldn't take you half a day. Unbolt those flanges on the halfshafts, undo the plates holding the diff in place and lower it out. Since you're extending the wheelbase, you either already have the PPF undone at one end or you need the PPF undone at one end.

No reassembly needed to use the rear for mockup, you can let the outer part of the halfshafts flop around. Or you can remove the wheels, take off the hub bolt and remove the outer part - which you'll have to do anyhow. Then you put the wheels back on. This is all work you'll have to do at some point and you'll get $100 out of the deal.