In June, I decided it was due time to replace the existing KYB AGX struts on my 90 GXL with new ones. During month of June, KYB was offering a $25 rebate on set of four struts. I bought them from Rockauto using their discount code. So, I got a good deal on set of four KYB's using Rock's 5% discount code and the KYB rebate. My existing KYB's had over 149k miles and had been on my car for about 17 years. I kept my existing springs, which were the Eibach Pro-Kit variable rate springs.

Last month, I replaced the rears first and about two weeks later replaced the fronts. I had the MazdaSpeed competition upper strut mounting blocks (p/n FBY1-34-380) on the front. These mounting blocks had 149k miles and I wanted to replace them with the same, but found out after talking to Mazda Motorsports (MMS) that they were back ordered for 30 days, maybe 60 days or even longer. Atkins had them, but I didn't want to spend $95 each when I could get them from MMS for $65 each. I ordered the Mazda stock mounting blocks (p/n FB01-34-380C) online for about $80 each. BTW, the dealer told me that there were only 7 of these left in Mazda inventory in North America.

Most of the old rubber bushings were shot. Here are some photos.






I replaced the rear spring cushions (p/n FB01-28-040) and rear bellows/bumper (p/n FB01-28-014) with original Mazda parts. As you can see, they are torn-up badly. Time does take it's toll on these rubber bushings. Actually, I just ordered a couple more new bushings from Mazda for the rear, and am going to replace them when the parts arrive. The rears were really easy to do since I didn't even need to use a spring compressor. I didn't even need to removed the rear wheels for this job.

The front's probably took a little more time, but not much more. Here are couple photos of the front.





The thing that really worried me about the fronts were that rusted mounting flange. Actually, if you look at it carefully, it appears to be bulging between the two bolt holes. This is the main reason why I really wanted to replace these guys. I also replaced the rubber spring cushions. You can see how torn-up they are. The front and rear spring cushions were last replaced about 22 years ago. The front bellows/bumper were the original that came with the car. So, they had over 30 years on them. I replaced the front bellows with Mevotech (p/n MP63621) that I also bought from Rockauto. The Rockauto website listed these particular bellows as rubber versus the other brands which were plastic. When I received them, I found out that they were not rubber, but also plastic.

My impressions are as follows. I have probably put 100-200 miles on these struts so far. I have both the fronts and rears set at position number 2, which is usually what I had the old ones set at. At position number 2, on all four corners, the new AGX's appear to be a slightly softer than the old ones. I used to have a weird vibration that now appears to be gone. This vibration would occur when I was neither accelerating nor decelerating. Kind of hard to explain, but it would happen when I was cruising on level road with foot steady on the gas pedal. Not sure what was causing this. The upper strut mounting bearings looked okay. It might have been due to the rubber isolators in the mounting blocks. Like I mentioned earlier, these suspension rubbers will go to $hit after 17 years. The car is a pleasure to drive now. So far, I've cruised at about 80 mph, and it's smooth and handles like it's on rails.

 

take that literally, they don't stock much stuff in the USA.

boy those bushings are all really bad,

 

Yeah, just today I ordered the top bushing (F044-28-015) and metal plate (FB01-28-020), as are shown in photo #3. The dealer told me that there were only two of these busing left in Mazda inventory at their Irvine warehouse.