K said last week it seems I only work on cars at this time of year. I guess she's right. I have no idea why that is. But alas, it was time to do more work on Maverick, our beloved Mazda 5. A while ago I noticed there was a lot of grease all around the bushing on the driver's side axle. So I ordered one and, last week, got to work. I should mention I've never come close before to replacing an axle on a vehicle.
Spoiler: it was a success.
I've come to realize working on cars basically involves three steps:
- Loosening some bolts
- Replacing a part
- Tightening some bolts
The bane of any auto repair however, IMO, is jacking up the vehicle. Once that's done, the fun can begin.
For this job of replacing the axle, that 'fun' required breaking loose the 34mm axle nut. It was torqued to about 200 foot-pounds. That's some good times right there. I wedged a big crow bar between the wheel studs to keep it from spinning (the other option would be to have someone press the brake pedal), got my 18" breaker bar and the steel extension pipe from my floor jack, and pulled up really, really hard.
It didn't budge.
Then I remembered the nut had a flange on it that was hammered to lock it in place. I had to punch out the notch. Once I did that, and with the same setup and brute force, the nut broke free. Yay! I honestly felt like that was the crux of the job.
Real quick, the tools I used for this included:
- 34mm socket for the axle nut (torque 200 ft-lbs)
- 14mm socket for the lower control arm ball joint pinch bolt (torque 39 ft lbs)
- Breaker bar (pretty much any job requires a breaker bar, which is a pretty fun tool to use I'm not gonna lie)
- Torque wrench (the click type, because I’m a stickler for torquing bolts to spec)
Speaking of the lower control arm, when I went to separate the ball joint from where it connected to the wheel hub in order to pull out the axle, I noticed a lot of grease coming from the joint. So I ordered a pair of lower control arms. I'd end up replacing the one on the driver's side as soon as I got the axle installed.
With the lower control arm separated from the hub, I was able to finagle out the axle.
It was then simply a matter of pulling the other end of the axle out of the transmission case.
Not unexpectedly, transmission fluid leaked out. Unexpectedly, kind of a lot of fluid leaked. I quickly grabbed some containers to catch it. Turns out:
If the "mechanic" has your car lifted on one end while the nose was higher than the rear, fluid would leak from the hole where the half shafts insert. If the car was not level, the fluid would over spill out the half shaft holes. This will lead to a lower fluid level. When the car is level, the half shaft hole is higher than the fluid level, thus no leaks.
Good to know. We don't happen to have a post lift in our garage so yes, the front end was up on jack stands. I'd deal with the lost gear oil once I finished installing everything.
Next up was installing the new axle. I aligned it in the transmission case and pushed without success. There's a spring clip that creates some resistance (shown on the left of each of the axles, the new one is on top in this photo):
I was wearing some nitrile gloves that were a little slippery, so I thought I'd put on a burlier pair of gloves. With those, it took one shove to get the new axle seated in the transmission. Boom and double boom.
Comparatively, it was simple to get the new axle inserted into the wheel hub.
Since I already knew I was going to replace the lower control arm, I just completely removed it from the frame. With the new axle in place, it was time to install it. First step, I took the bump guard off the old one and moved it to the new one.
Quickly, in addition to a breaker bar and a torque wrench, the tools I used for this included:
- 19mm socket for the bushing bolt (torque 110 ft-lbs)
- 17mm socket for the plate bolts (torque 75 ft-lbs)
- 14mm socket for the ball joint locking pinch bolt (torque 39 ft-lbs)
The catch I realized (after doing it wrong) was having to install each of the three attachment points in a certain order. First, the two 17mm plate bolts. It had two captive nuts that made finagling it just right a little finicky. Hence, it was critical to install those first.
Then, it was simpler aligning the bushing and installing the big ol' 19mm bolt. Simpler still was lining up the ball joint with the hub. I used my floor jack to nudge it up into the hub.
With that, the lower control arm was installed. At this point, I torqued all of the bolts to spec, including the burly 34mm nut on the axle. Also, I punched the flange to lock that thing in place.
In order to get access to both the axle and control arm I took off the brake caliper and rotor. When I looked at the rotor, I noticed it basically resembled a vinyl record. Not awesome. I'm sure that's what was causing the wobble when we'd brake at higher speeds. So I ordered a new pair for the front wheels.
When I installed new brake pads last year, I didn't swap out the rotors. It was time.
In fact, K and I think the guy who owned Maverick before we bought him slammed into a curb or something on the driver's side. That would explain the wrecked axle and lower control arm. My theory about the rotor goes like this: with both of those out of whack, the pads wore the rotor differently than the passenger side (which didn't show the same signs of wear). Either way, it'll be good to have new rotors and the job was super-simple.
Though the pads were in great shape, I took the time to apply anti-seize and silicone lube to the calipers, guide pins, and pads. No need for them to squeak. In short order the driver's side was done and I whipped off the passenger side wheel to repeat. Worth noting: since the new rotors were slightly thicker than the old, I kept the bottom pad in place and used a C-clamp to quickly compress the caliper.
Also, for reference the following tools were used for changing the rotors:
- 17mm socket for the caliper bolts (torque 70 ft-lbs)
- 7mm hex socket for the guide pins (torque 19 ft-lbs)
Then it was done. For fun, I took some photos of the passenger-side axle and lower control arm.
At that point, I could put the wheels back on and lower the car to the ground. Then torque the lug nuts to 75 ft-lbs.
The final step was dealing with the lost transmission fluid. We ran to Autozone and I picked up a quart of 75W-90 GL-4 gear oil. It didn't take long to locate the transmission fill and drain plugs (red and blue, respectively, in the second photo below, both 23mm).
Never having filled manual transmission oil before, I figured there was a reason it came in a squeeze bottle. The fill hole points down, after all. So I awkwardly squeezed oil up until it started to drip out, almost a full quart. I assumed that meant the fluid level was topped off. Also, that was about the amount I measured which had spilled into a yogurt container.
With that, the job was complete. I took Mav out for a test drive. Solid. Except K and I could still hear a clunk from the passenger side. I'm hoping that'll be fixed by installing the other lower control arm that came in the set. The catch is that side looks like it'll require jacking up the engine in order to remove the 19mm bushing bolt. That'll be good times.
All in all, this job was really satisfying. Also, now I know more about a vehicle's suspension and a little more about the transmission. Really, like I confessed to K, I only work on our cars so I can buy tools. Just kidding. But seriously…
