NB MX-5 Hey, it's Minnie!

[chiefmg]

The weather finally got warm enough to get some work done. Hoisted her into the air, pulled and calibrated the wideband O2 sensor which I hoped would correct some surging I had when I took her out the other day. Then I moved to the rear. Removed the lower diffuser and my temporary muffler hanger (which had been installed for something like two years). I then set up the new hanger I bought:

I need to buy myself some proper ViseGrip welding pliers to make this easier the next time. I didn't have any stainless stock to practice on and my first attempt (which was vertical) was barely good enough to get it stuck in place. I ended up removing the muffler to do flat welding. Not the best I have ever done but it's solid and only ended up a little off-set:

Once that was done I put it all back together. I forgot how much of a PITA a couple of the screws at the back of the diffuser were to get in place. I literally was straining to put the middle one on the passenger side together. If I did any sort of bulk exercise I would have been screwed. In any event it is all back together and as can be seen, the muffler is well clear of the previous impact zone on the diffuser:

 

[chiefmg]

Last Saturday I got out to the garage repack my new hubs. I followed the how-to listed here:
https://www.miataturbo.net/suspensio...ont-hub-75372/
I should note that when I disassembled my bearings the retainer with the protrusions that is shown as being for the outboard bearing in the above thread was in my inboard bearing. Don't know why the difference, I recommend doing yours one at a time and making sure you don't mix up the parts. Other than that one change, everything else worked well. Here are some pictures of the hub as delivered, one of the bearings disassembled, the retainer with protrusions:

You can see I put the separated bearing parts into a labelled cut down water bottle so I didn?t mix them up.

I used the following cleaner I picked up at Tractor Supply:

Diluted it with water and put it in a container I bought to use as my cleaner:

Wiped off all the grease before I put the parts into the solution. Swished things around a little to clean them, then removed them and wiped them down. Some compressed air helped with the backside of the retainers (they are slotted), a Q-tip worked great to clean the recesses for the balls in the retainers. After that I assembled everything, greased it with some Redline CV-2 and set them aside.

Monday I went about replacing the hubs. Pretty straightforward with the right tools. Since I was doing this job I decided to put the correct dust shields on for my new Sport brakes. For anyone thinking about doing the same, here are the part numbers for the right ones:

Kind of hard to see it, but these have a protrusion that fits behind the caliper bracket (it's on the left side of the left-hand shield in the picture) that the original shields did not. I cleaned all the stickers off before installation. Here's a shot comparing the two differently sized shields:

Remove all the brake parts (like if you were replacing your rotors). The hardest part of the job was removing the dust cap that covers the hub nut. Used some AeroKroil and then flat-bladed screwdrivers to pry it off. Used my Milwaukee 1/2" impact to remove the hub nut after prying up the staked part. Once that is off the hub slips right off. Dust shield is held on with three bolts, pulled that off and cleaned everything up. After that it's just a matter of assembling in the reverse order. You have to jiggle the new hub a little to coax it to slide on. I put the hub nut on and hit it lightly with the impact to give it an initial seating:

Put all the brake components back and put the wheel on with the center cap removed. I torqued the lug nuts before the hub nut. You need to have some of the car's weight on the wheel before trying to torque the hub nut. I used 170 lb-ft for my setting, this is recommended by Mazda Motorsports for racing use. My final setting is a bit less because I have to use a short extension between the socket and my torque wrench for clearance.

Once the hub nut was torqued I jacked her back up, removed the wheel and then staked the hub nut. Put the dust cap back on (tapped it in using a dead-blow hammer) and then put the wheel on for the final time. Test drive showed everything to be good.

 

[chiefmg]

That’s finally up to the present. Anything moving forward will be current.

 

[chiefmg]

She’s been acting strangely so I did some datalogging yesterday while driving to two C&C gatherings. Looking through them I didn’t see anything out of the ordinary. Checked some settings and found that Boost Control was turned on along with some strange drivers for the injectors. I got rid of those and burned the changes to the MS. Today while out driving she wasn’t running right, I shut her off to cycle things and then she wouldn’t restart. I had my computer connected so restored to a previous save point, which allowed her to start. Headed for home and she exhibited bouncing of the AFR with surging and other strangeness. I don’t see anything in the MS that is obvious so I’m going to check all my connectors and wiring to make sure nothing is loose or chewed by varmints.

With my new welder on hand I realized I could do the brake master cylinder brace myself. While looking to be sure I knew the material of the shock brace, I found that Moss has a brace designed to bolt directly to the Cobalt two point shock brace. It will give me all I need, and hopefully it is long enough to span the opening on my shock brace so I can just weld it in (it not then I will be doing some filling). That is on order so I can get that job done soon.

 

[chiefmg]

The master cylinder brace arrived today. Here is what you get:

There are also a couple of nuts/bolts used to attach it to the other shock brace but I don’t care about those.

I positioned it so the body of the brace was wholly on the left side mount of the shock brace, but that won’t work:

In order to have the brace touch the master cylinder I was looking at only having a couple of threads engaged in the long nut. So, on to the next idea:

I screwed the brace into the long nut and then messed with where I could put the body. I was thinking I might have to get some stainless plate and make a L shape, but looking at everything I will be able to weld all around the body including on the back side. That should give me more than enough strength.

 

[chiefmg]

Made a run to Harbor Freight to pick up some pliers etc for welding. When I got home pulled some pieces off so that I could target the MC brace where I would weld it:

Pulled the shock brace off and commenced to welding. Again, not my best as I am still coming to grips with setting up the wire feed welder. But hey, grind some of the ugly down and it isn’t too bad:

Assembled everything back together, adjusted the MC brace bolt and voila:

Haven’t gone for a drive yet, but pushing on the brake pedal while sitting shows a pedal that has zero give. Can’t wait to see how this impacts my braking (I have driven other cars with a MC brace and it does great things for braking feel).

 

[chiefmg]

As mentioned I have been having drivability issues. Took several datalogs. I was getting surging under many modes (including steady-state throttle), gas consumption was way up and I just couldn’t trust not having problems. In looking through the logs I was trying to spot any inconsistencies (there is a lot of data to absorb so pretty difficult). One thing I noticed was fluctuation in the TPS (throttle position sensor) %, even when it was in a steady state. I also performed the calibration of the TPS within the MegaSquirt, and found differences each time in the zero setting. With the thinking that the last thing you touched probably being the cause, yesterday I swapped back to the original TPS that I had changed out last year while chasing my stumbling issue. Took her on a short drive this morning to get the tank filled, and there were zero issues. Feeling lucky I then drove to a C&C. Freeway miles along with in-town, and I am happy to report everything was still good. I feel certain I solved the problem at this time. Lesson learned for me, I will not be buying any more cheap electronic parts in the future.

 

[CTt3P5]

What a great journey, thanks for sharing it with us Mike!

 

[chiefmg]

My pleasure. It's been a pain sometimes, but also a lot of fun.

After a couple of search attempts, I found the rear 949 subframe brace at my storage. Crawled underneath and installed that this morning. With the new muffler hanger in place, I have space between the brace and the exhaust which means I can leave it on. This makes me happy.

Neglected to post it, but after several drives now with the MC brace in place I am really pleased with the brake pedal feel now.

New rear bearings have arrived.

 

[chiefmg]

Swung by the dealer and ordered the correct larger brake dust shields for the rear.

Hoisted her up into the air to try adjusting the muffler position. Accomplished this by whacking the new muffler hanger with a hammer. I’ll see if this lets it maintain correct position side to side. If not then I will probably cut the hanger off and reweld it.

The four nuts that connect the upper and lower rear diffuser pieces are a royal PITA to get in place. I have some construction adhesive that I used to glue down the stopper for the wife’s car that seemed to work well, so I gave that a shot. Put some around the perimeter of the nuts, then put them in place with the screws and left for a while to harden up before assembly.

This worked on three out of four, the last one came loose but it was one that I was able to reach. Maybe once the adhesive hardens overnight it will be good.

 

[chiefmg]

A few weeks ago I took the plunge on a new set of door bushings. These are made by a friend over in Greece who has started a business producing certain Miata parts (you can find him at https://www.instagram.com/dcbe.tech/). It took a little over two weeks for me to receive them via USPS. What sets these apart from the usual Delrin type is they have a solid core with a rubberized coating. The cross-section is different as well. New type is on the left in the pictures:

He also includes stainless socket head cap screws as part of the package. Installation is like other door bushings. I did have to mess with the passenger door bushing a few times to get it just right (probably something to do with that door on my car). End result is great. Same feeling of solidity with a much easier closure of the doors with no sanding of the bushing. I can recommend these.

 

[chiefmg]

Finally set about repacking my new rear wheel bearings. Followed basically the same procedure as I used for the fronts with some slight differences. There are two seals on the rears and I didn’t see any way of removing them without damage so they stayed in. I did end up removing the backing spring as they kept popping out and that was easier (don’t lose them). Same for the balls and retainers, everything was tight in there. I wedged pennies between the two inner races, drove out the first one then flipped the bearing over and drove out the second one. It seemed like there was a slight difference in the curvature of the two races so I made sure not to mix them up. I wiped out as much of the old grease as I could, it was white which I have never seen in a bearing grease. Then I soaked it in hot water and the same Oil Eater cleaner I used on the fronts. Took several washes/blowing out with air in order to remove the old grease since nothing could be taken apart. Then in with the new synthetic grease, install the seal springs and put the races back in. Note with this step you have to be careful that the lip of the seal doesn’t get folded under the race. Those are both done and ready for installation.

 

[chiefmg]

Washed her dirty butt two days ago. Also started the installation of my air line from the compressor location to the hose reel by the garage door (finally).

Had to order a couple of fittings to finish, those came in today. This means I won’t have to run the air hose from the compressor all the time when I need it in the driveway. I am a little concerned about others using it because of the proximity of the hose reel to the Miata, but I can fix that while I’m gone.

 

[chiefmg]

Today I finally got around to adding an electrical receptacle by the garage door. I did this mainly to make things easier when using the Miata’s battery charger while gone. Bonus is it means I won’t have to run an extension cord when vacuuming cars outside etc. No pictures as all I had to do was drill a hole through two 2X4s, go into the attic and run the wire, figure out which circuit breaker fed the receptacle I was tying into, then hook everything up and check for voltage. Just a simple little up-and-down job.

 

[chiefmg]

Gave her a bath, pulled into the garage and connected the battery charger for her nap.

 

[bazooka joe]

Great thread!

 

[chiefmg]

Thanks Mark.

I won't get to see it for a few months, and once installed no one will know it is there, but I purchased something from my friend Harry B. Y'all gonna have to wait until September or thereabouts to find out just what it is.

 

[bazooka joe]

Harry B? Should we know him..?

 

[chiefmg]

Sure, if you got out more... I bought my door bushings from him, I posted his Instagram a few posts back. He's in Greece and has started producing some parts for Miatas (he has an NB). He is working towards a website but for now everything is via his Instagram.

 

[bazooka joe]

Sure, if you got out more... I bought my door bushings from him, I posted his Instagram a few posts back. He's in Greece and has started producing some parts for Miatas (he has an NB). He is working towards a website but for now everything is via his Instagram.

But in all fairness, I don’t think you mentioned his name!
I’ll check him out