I’ve just learned a pretty shitty thing about my Miata. So the previous owner purchased an LS trim Miata with a Limited Slip Differential in 2001. As the original owner, he fastidiously kept track of all maintenance and had a shop do every repair. Well part of that maintenance included replacing the differential in 2016, which would have put the mileage on the car just north of 200,000 at the time.
So this receipt I recalled questioning before purchasing the car. The description of “used diff” is relatively nondescript and I wondered if an open diff could have inadvertently been used. The price seemed kind of cheap for a torsen but $650 isnt totally out of reason for junk yard/salvage parts. So I figured maybe it had high mileage on it and the shop sourced it on the cheap. Fast forward from my purchase in April of 2019 to now in August and I had to have the diff serviced to solve a leaking differential case. I didn’t want to do it myself since it was leaking bad enough that I wouldn’t be able to make it to where I work on the car without running out of fluid.
Well the shop took the diff out of the car to reseal it. I was more concerned at the time that the previous owner had used a 4.1 diff instead of a 4.3 (mazdaspeed diff that nobody likes and is slower) since that would be also useless to me. But to my surprise the shop let’s me know I have an open differential! What that means is that I paid a solid $1k too much for the car since LSD is the number one selling point on these cars.
Now I’m just pissed because I’m not going to be able to sell the LSD from my other car and I have to redo the work the shop did anyways to swap it in. I just hate feeling ripped off though since everything else has gone so well with this car relatively. I have a few issues to solve but all of them are track reliability of a 250k mile car.