I'm up to 186k miles now, which means I've put 5000 miles on in a month of owning the car. I guess I really like driving it or something, eh?
Most recently I took it down of my favorite roads, and it was fun to push the car a bit. The only downside was that I cooked the already warped rotors some more, oops.
The next day, I ordered some brake parts and replaced the front rotors, pads, and wear sensor (Zimmerman coated rotors, ATE pads, OEM sensor). The drilled rotors might have looked cool, but they were not straight at all, and caused a fair bit of shaking upon braking (control arm bushings have been done, so definitely a brake shake). I generally don't run drilled rotors for this reason, they don't really do much for performance and have a higher chance of warping/cracking when pushed hard.
After that, I bled the brakes at all four corners, and to say the fluid that came out looked bad would be an understatement...
I don't think the fluid has ever been flushed on this car, yikes. The bleeders were quite stuck too, which supports that theory. After 3 rounds of bleeding with my pressure bleeder, the fluid coming out still looked black, but at least now it was free of air and was marginally... better? I'll probably order some new lines and do a proper flush of the braking system in the future, but for now, this will do.
While the car was up on the lift, I also changed the oil. It was a bit early since I had receipts in the glovebox showing the oil being changed around 181k, but I wanted to put in a heavier weight since the receipts showed it being 5W30. Somehow the oil that came out looked pretty bad too, hm.
I put Castrol Edge 5W40 in, that seems to work nicely in the M54's in the hot Arizona climate. The oil filter was replaced with a Hengst one, I prefer those to the Mann ones because of the plastic end caps that don't seem to fall apart.
After thoroughly bedding in the brakes, I can confirm that they work great now. I can slam the brake pedal at 100+ and the car slows down in a smooth, predictable manner. The pedal seems to feel a bit better too, so bleeding the brakes seems to have helped.
Earlier today, my diff bushing tools came in from GST, so of course I immediately got to work.
I've been meaning to replace my CSB and flex disc for a while, so it made sense to do it at the same time as doing diff bushings. The exhaust came off with very little drama, followed by the heat shields. Looking at the CSB, you can tell it's completely shot:
I don't think you should be able to see through it...
Looking at the flex disc, it didn't look too awful, but it was starting to crack and random fibers were starting to come off of it, so I figured it would be good to take care of it before it became a problem.
With the exhaust and driveshaft removed, it was really easy to pull the diff. I also removed the rear sway bar so I wouldn't have to fight it while pulling the diff.
You can see the diff bushing cracking apart, this one was replaced in 2010 but was already going bad. It wasn't quite as torn up as some of the really bad ones I've replaced, but it was still enough to cause an occasional thump when shifting and going on/off throttle in certain gears.
The new tools made this job an absolute breeze. For the rear bushing I went with Meyle HD as I've had good experiences with this part on customer cars over the years. For the fronts I put in Lemforder bushings.
One thing I noticed as I was reinstalling the diff was the label on top— apparently this is a 3.38 diff, not the stock 3.07. That explains why the gearing feels a bit short. It's interesting finding all these little mods/changes throughout the car.
Moving onto the driveshaft, the CSB bracket fell right off as soon as I split the driveshaft, so I had to get a little creative to get the remnants of the CSB off. It ain't dumb if it works!
The new CSB was tapped on and the driveshaft was reassembled. I marked both halves before taking it apart, so there shouldn't be any balance issues.
Of course I couldn't help but replace a few more things while the driveshaft was out... so I replaced the rear shifter carrier bushing, as well as the round white shifter bushing. The front carrier bushings and selector rod joint looked to be in okay shape so I left them alone. In addition, I also replaced the transmission mounts. The old ones weren't too bad, but they were starting to crack from age so might as well swap em out, especially with Corteco mounts being less than $10 each.
Putting everything back together, I also replaced the exhaust gaskets since the old ones looked crusty. Otherwise, nothing notable to say about the reassembly process other than me being hungry as it was dinner time and I had to put the car back together to go home.
Oh and at some point in the day, I also replaced the passenger front seat control panel, as the seat back adjustment wasn't working at all. The new panel seems to have fixed it, so now my passengers can enjoy the ultimate luxury of a fully functioning seat.
That's about it for this update. It's still hot as heck in Phoenix (my shop doesn't have AC, just a swamp cooler that does nothing when it's humid like it has been lately) and I need to actually go do customer work so I can buy more parts for my car.