Copper 2007 FX35 AWD build thread!

Hi everyone, I could use some help with my transmission fluid level. When I replaced the pan and rubber hoses going to the rad/cooler, about 7 quarts drained out. Capacity is 10.9. I didn't check the level before draining, but since the FX has only been serviced at the dealer, I figured the level would be correct. I refilled with about 6.5 to make sure I didn't overfill, but when I checked the level, it was reading crazy high, like at least one quart over. I wasn't sure if the fluid to the cooler is controlled by a thermostat, so I drove it around town for a bit, hoping the thermostat would open and let the fluid go into the cooler, but even after that the fluid level is still way too high and it doesn't look like it went down. I'm following the level checking in the FSM where you rotate the dipstick around 180* before inserting. No matter which way I insert the dipstick, it doesn't want to go down smoothly, and I have to force it a bit. Is this normal?

Now I need to figure out if I simply try to match the amount that drained out, hoping the dealership did it correctly, or if I trust the wonky dipstick and drain some out. I know overfilling is bad, but so is underfilling. What are your thoughts?
 
Ever since we bought the FX, I knew that there was a good amount of rust on stuff under the car, but from what I could tell, the body of the car was in very good shape. I wanted to remove the worst offenders, clean them up, and then paint them with POR15 so they wouldn't get any worse. I figured I would start with the three cross braces, front, mid, and rear. The mid brace was by far the worst. Sounds easy enough, right?

Except I made mistakes every step of the way, which made the project spiral out of control, and ended up taking something like a month to complete. Thankfully, my wife has been working from home during the pandemic, otherwise we would have really been screwed. I at least learned quite a bit from my mistakes, so when I do a similar project on my I30, it should go much smoother.

The front brace came off without issue, since I had just had it off to replace the trans pan. The problems started when I went to remove the mid brace. There are four M10 bolts towards the front, and then three M8 bolts on each side at the rear. I recently purchased a fancy new big Milwaukee impact gun to help out when my compact Dewalt wouldn't cut it, and I was eager to use it. First mistake. The six M8 bolts at the rear were looking pretty rusty, but due to being about 3" from the gas tank, I didn't want to use my MAP torch to heat them up. Well, I hit them with the Milwaukee, and two came off, then one broke. Not thinking about what really just happened, I moved to the other side, and all three snapped off. Oh crap. I'm pretty sure that if I had removed them by hand, this wouldn't have happened, but I was too eager to think clearly about what was needed in the situation. We'll come back to this problem later.

I made another mistake when I went to remove the rear brace. Before starting, I looked at it and noticed that if I remove the nuts holding the brace on, that would also allow the rear subframe to come down, as the nut supported both the brace and the subframe. But I quickly forgot about that somehow in the rush to do things, and just zapped the nuts off without really thinking about what was about to happen. Well, wouldn't you know it, the rear of the subframe dropped down hard when I removed the second nut. Oh crap! If I had just supported the diff or subframe with a jack, that wouldn't have happened, but I just wasn't thinking clearly. We'll come back to this problem later as well.....
 
Let's break up the wall of text, and skip ahead to some actual progress pictures. I'll get back to how I worked through those problems later.

My painting process went like this:
Grind off all rust with wire wheels and angle grinder
Soak parts in Evaporust
Grind off more rust
Prep surface with POR15 degreaser and metal prep products
Paint with POR15, usually three coats

Here's how the front brace went. It was in pretty good shape to begin with.

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Cleaned up and soaked in Evaporust

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Painted

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Now for the mid brace. This was the impetus behind the whole project, this thing was looking like swiss cheese, and I wanted to fix it rather than spend $250 to buy a new one. It kept getting worse and worse the more I ground off the rust. Even though it lost a lot of material, it should still serve its function.

Here are the offending bolts that snapped off:

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Here's how it looked when I pulled it off the car:

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Then I ground it down:

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I could only fit so much of it in my 5 gallon bucket of Evaporust, so you can see the area that wouldn't go in the bucket:

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Ground it down some more....

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After the POR15 prep stuff

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And painted:

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It ain't pretty, but it should last another 10 years now.
 
The rear brace was in pretty good shape, but I wanted to paint it anyways. It looks like I forgot to take pics before I cleaned it up with the wire wheels.

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After POR15 prep:

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And painted:

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After I removed the braces, I noticed that the areas on the body that they attached to were looking a little crusty, so I gave them the same treatment. I figured that these are areas that can trap moisture and debris against the body, so painting would be a good idea.

Front brace:

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Mid brace areas before cleaning (this is the rear):

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Ground down:

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Prepped:

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Painted:

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And this is the front:

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And the area above the rear brace:

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During this process I tried to reuse some nuts and bolts. To do this I would clean them up with a wire wheel, soak them in Evaporust, and then wire wheel them again. I then painted some as well to keep rust from coming back.

These are the ones for the front brace:

Wire wheeled:

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After Evaporust:

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And wire wheeled again:

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Finally painted with some high temp caliper paint:

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Now I only have one 5-gallon bucket of Evaporust, and clearly these braces weren't going to fully submerge in it, so I had to flip them around and sometimes get creative on how to get the center areas submerged.

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And these are my POR15 products:

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Before I started this job, I knew there was a small exhaust leak somewhere, but I didn't know where. Once it was up on the lift, I quickly found the location at the muffler:

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The FSM says to remove the muffler by removing the metal support arms, but since mine were so rusty, and I had just snapped off a bunch of bolts for the mid brace, I decided to just wrestle off from the rubber hangers. It worked, but just barely.

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I cleaned up the area around the flange and the hole just kept getting bigger....

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But a new OEM muffler is like $750, and I sure as hell didn't want to install a Bosal replacement, so I had a buddy (thanks Brian!) weld it up for me.

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I had planned on painting the muffler since we bought the car to keep it from rusting further, and now was as good of a time as any, so I got busy and cleaned it up. Here's how it started out:

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After cleaning with the angle grinder:

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Then after the POR15 metal prep. This stuff really dissolved a lot of surface rust very quickly!

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And painted with some high temp header paint I had lying around:

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Then it was time to polish these dirty tips:

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Some 000 steel wool and Mothers Mag & Aluminum polish cleaned things up real nice:

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And with that, my muffler is as good as new, maybe better!
 
Aside from the rusty braces under the car, there was one other piece that really pushed me into this preventative rust repair project, which was the box that houses the EVAP stuff by the gas filler neck.

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Yeah, that's a scary thing to see under your car. And I didn't know what lied above it since I couldn't see very much. So with the muffler out of the car, I figured oh what the hell, I might as well do this now too. So I removed the box, and luckily only snapped a single little bolt off in the process.

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I also pulled the exhaust hangers:

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The tow hook thing:

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And another metal piece that was on top of the EVAP stuff:

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I cleaned it all up with the angle grinder and soaked everything in Evaporust again, and it started looking like this:

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But I didn't like all those jagged edges, so I cut out a square with my dremel to make the damage less obvious:

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I had the lower control arms off (that's another story...) so I cleaned them up too and got them ready for POR15.

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The hardware got cleaned up too:

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I somehow forgot to take pics of everything after paint, which is disappointing since it was all so shiny and pretty, but oh well. You can see the assembled pictures later.
 
And now we can move onto the rust repair at the rear of the vehicle. I was able to get a much better look at things with the muffler out of the way, and I knew I had to take care of this stuff now before it got out of hand. Hooray, more work!

Here's the area around the EVAP stuff with the two metal pieces out of the way:

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EVAP stuff removed:

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Then I got real busy with the angle grinder and some tiny wire wheels on my Dremel:

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Thankfully nothing had gone through the metal, so it could easily be saved. To prep for POR15, you first have to use their degreaser product, then their metal prep product. Except that after each one of those, you have to thoroughly rinse the area off with water. Well, that's a large surface to clean, and wet paper towels weren't going to cut it. So I brought the hose into my garage, laid down so buckets, and sprayed everything down to clean it up. It was messy, but necessary and worth it. I then hit everything with my leaf blower to speed the drying process along. The following day, it was ready for paint.

I painted all parts with three coats of POR15, and I'm very happy with how it all turned out. Anything that was rusty before was now coated in POR15, and would not rust again. For the larger areas that hadn't started rusting, I did something else. I sprayed the outer surfaces with Corrosion-X, and then I sprayed the internal cavities with 3M Cavity Wax Plus. I have some long nozzles for the CWP that allow it to spray in a 360* pattern so all four sides of the "boxed" sections receive a coating of the wax. I sprayed CWP in two coats until it started dripping out of all the holes. It dries to a firm coating that prevents any moisture from coming in contact with the metal and should make it so these areas can't rust out from the inside. I think it's now pretty safe to say that the rear 1/3 of this vehicle will not rust any time in the future. POR15 and the CWP are permanent coatings, the Corrosion-X may need to be reapplies in some areas over time.

Here's how it all turned out. You can see the Corrosion-X all over everything, it's still wet here and makes everything look shiny.

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Reinstalled the EVAP stuff and boxes:

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The heat shield:

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Tow hook:

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Control arms and muffler:

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And with that, the project was done. Oh wait, it wasn't? Crap, guess I need to keep posting things that nobody is ever going to read.
 
So during this whole process, lots of pieces of rust fell off various parts of the car. None were from the actual body, just things like the braces, and this one piece of super rusty metal that seems to be some sort of heat shield behind the fuel tank and in front of the rear subframe. For the life of me I can't figure out what it's purpose is aside to rust and drop rust all over me. So I started making a pile of all the rust that came off the car:

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It kept growing, until it evolved into its final form:

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Like I said, 90% of that came from that weird heat shield divider thing that serves no purpose.

I mentioned previously that when I was removing the mid "W" brace, four of the six rear bolts snapped off when I went to remove them. This was mostly my fault since I was over-eager to use my new super powerful Milwaukee impact gun, which was way too powerful for bolts this size. I'm pretty sure if I had used my smaller Dewalt, or taken them out by hand, I wouldn't have broken nearly as many. Unfortunately, they are all about 3" from the gas tank, and I wasn't comfortable applying my Map torch to them to help loosen them up, as that would have undoubtedly helped. Either way, I had to extract four of these damn things, and to make a long story short, I made even more mistakes trying to extract them, and spent a good full three days getting them out and rethreading the holes. It was truly a miserable experience, but I thankfully learned a whole lot in the process, so I hope to not make those mistakes again.

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I also mentioned how I made a terrible mistake when removing the rear brace, and dropped the rear half of the rear subframe down in the process:

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This, of course, led to a cascade of new problems, which led to much more work. I first attempted to press the subframe up from the rear diff with my trans jack, but it would only go so far before lifting the rear of the car off the lift.

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After many hours of trying different things, it dawned on me that the rear springs probably needed to be removed. So I then read the FSM on how to remove the rear springs, and it said I should loosen the inner eccentric bolts for the lower control arm that holds the springs. Sure, no problem, right? Hahahaha, no, of course it was a problem! The PS LCA came off without too much fuss:

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But the inner eccentric nut/bolt were completely seized together on the DS.

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No amount of penetrating oil, heat, and super powerful Milwaukee impact gun could loosen the nut. After much cursing and frustration, I somehow ended up making the entire eccentric bolt/washer/nut assembly spin 360*, which completely rounded out the vertical slot that held the eccentric in place. Jesus Christ, what have I done?

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And still, I couldn't separate the nut from the bolt, so I had to get out my Dremel and a cutoff wheel and saw it in half.

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Which left me to deal with this mess:

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Yeah, those raised edges on either side of where the eccentric used to be are supposed to be straight, not rounded.

So I got some new hardware:

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And begged my super talented buddy Brian to do a freaking house call with his TIG welder, and add material back to the freaking aluminum subframe. Thank god I have a 220v outlet in my garage, but I had to buy an adapter so his TIG could plug in. After 20 minutes or so, I had material back:

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But of course I needed to grind it down to the correct dimensions to the eccentric would fit. Many hours later....

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What a clusterfcuk that was. But at least when I removed the rear springs, the rear subframe went back into place very easily!

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Hey, that's a little progress!
 
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Ever since we bought the FX, we knew the shocks needed to be replaced. The rear of the car would become unsettled when hitting irregularities on the highway. As far as I could tell, they were original and 13 years old, and had 130,000 miles on them. They weren't leaking, but I knew they were done. Since everybody rants and raves about how awesome the BC Racing coilovers are, I decided to install a set of those, since I wanted to lower the FX a bit. I have been running BCs on my I30 since 2011 and have had good results, so why not?

Because this car hates me, that's why. Something as simple as removing the rear shocks ended up taking hours. The large lower bolt came out without too much fuss, although the threads were still super rusty even after I cleaned them up with my Dremel, but the smaller nuts on top were a real pain.

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First, I had to use one of my weird S shaped wrenches to get them loose, as no sockets could fit between the body of the shock and sit flush on the nut, and I was not about to round those suckers off. But the thread on the studs were so rusty that the nuts just stopped turning at one point and wouldn't go up or down. And this is after I had everything soaking in penetrating oil and had cleaned up the threads with my Dremel. So I brought out my diamond tipped file set, and had to clean up each thread, one at a time, to clean out the rust buildup that was preventing the nut from moving.

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I couldn't use my tap/die kit as there wasn't enough room. Thankfully the files worked, and with a little help from my Map torch I was able to finally remove all of the nuts. With the shocks removed, I was able to chase the threads with my tap/die set and got them into acceptable condition. I'm really pissed that Infiniti made these part of the body, and not a removable part that could be replaced. If I had snapped one of these studs off I would have been really fcuked!

From there, it was just a matter of using my pass through socket set to swap the top mount from the stock shocks to the BCs:

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The paper gaskets at the top were completely worn out, and since Infiniti wants freaking $35 for each of them, I decided to make my own out of thicker gasket material:

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The fronts were pretty easy:

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I bought new nuts for all the stuff in the front, as of course the stuff I took off was rusty as hell:

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Mmmm, camber adjustment!

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And with that, the FX was reassembled, and we took it to RRT, a local BMW race shop where I take all my cars to get aligned. Of course, when they went to adjust the rear camber, those eccentric bolts/nuts were also seized, so they couldn't adjust them. But the rear camber was close enough, so rather than risk breaking even more things, I said it would be fine and we picked the car up. I was worried about how the drop and heavy 20" wheels would affect the ride quality, but since we were coming from blown stock stuff, ride quality actually seemed to improve a bit. You can feel that those wheels are heavy, as they clomp around over some potholes, but overall it feels good. I can tell the suspensions is definitely "breathing" with the road a lot better now, which is a nice feeling. I have both front and rear BCs at 10/30. I love the steering of the FX, there's no dead spot around center, and it's got a good hefty weight to it.
 
I washed the poor FX for the first time in a long time, and it shined up good! It does need some light correction, but not much.

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I think those 20mm spacers are going to be installed soon...

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Damn it looks good!

And with that, this project is complete. It feels really good to undo so much rust damage, and prevent it from coming back. I was only able to do this project because of Covid and my wife working from home, thus allowing me to keep it in the garage for over a month straight. It was a ton of work, and even more frustration, but it was all worth it in the end. I'm no longer scared to look under the FX when I put it on the lift. There will be more rust repair/preventative maintenance, but this should be the bulk of it.
 
Nice work! love your stance with the BCs, that’s exactly the drop I want when I purchase coils. Do you know exactly how much you dropped front + back? And is dialing in camber easy with the BCs ?
 
Nice work! love your stance with the BCs, that’s exactly the drop I want when I purchase coils. Do you know exactly how much you dropped front + back? And is dialing in camber easy with the BCs ?

I wish I did, the car had been inside on the lift for a while before I bought them, so I didn't get good before and after measurements. It looks like it's a 2" drop out of the box. I wouldn't mind it being a little higher, but I'm not sure if they can do that. Dialing in front camber is easy due to the camber plates, and rear would be easy if all my nuts and bolts weren't seized together! It's got a little more negative camber in the rear than I would like, but unless I get new eccentric bolts I probably can't do anything about it.
 
Great thread! You're car looks amazing with the paint correction and the lowered stance! I would maybe raise it a tad and that should reduce your rear camber a bit. Post pics when you get the spacers!
 
Hey Nick, thanks! So this is how the BC's look straight out of the box? I wonder if they are factory preset at the highest stance and can only go lower? Just something I want to confirm before purchasing. Keep up the good work!
 
Great thread! You're car looks amazing with the paint correction and the lowered stance! I would maybe raise it a tad and that should reduce your rear camber a bit. Post pics when you get the spacers!

Thanks! I'll definitely post up when I get the spacers installed. It may be a month or two, we'll see how it goes.

Hey Nick, thanks! So this is how the BC's look straight out of the box? I wonder if they are factory preset at the highest stance and can only go lower? Just something I want to confirm before purchasing. Keep up the good work!

Yup, this is straight out of the box for the BCs. I meant to call their tech support to ask that question but never got around to it.
 
While working on the FX's rust repair I was doing a lot of stuff around and in front of the rear wheels under the vehicle. This put me precariously close to the corners of my lift, which I inevitably bumped into multiple times with my head. One time I hit a corner so hard with the top of my head that I heard a nice crack (was it my skull? My neck?) and did some good bleeding. I vowed I would fix those damn edges before I got started on either of my two future projects that will put me in that area again, and this weekend I finally got around to doing them. Here's what those bastards looked like, there are eight in total:

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I started with a cutoff wheel, then a grinding disc, and finished up with a flap wheel. Now when I hit them it will simply hurt instead of causing potential brain damage.

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