R. Rallycross Miata Shock Replacement
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My son and I finally got to run the Rallycross Miata in a rallycross on January 26, 2014. We traveled to Sweetwater, TN to run the car at East Tennessee Region's first rallycross event for the year.
Well, everything was going well until we pulled up to the starting line on our second run and were told the rear of the car was sagging badly. The old original shocks had given up. However, they were still in tact mechanically, so we kept running and bottoming out the suspension on every bump. That sure made it hard to drive, but we had fun anyway.
By the time we finished, the drivers side front was also sagging.
So, on the way home Matt researched shocks using his I-phone. We decided on Bilstein HD shocks for the car if they were the problem.
The next day, I put the car on jack stands and removed the wheels to inspect the shocks.
This was the drivers side front shock. It was leaking oil badly.
The rear shocks were not leaking, but both had only remnants of bump stops remaining inside the dust boots.
All the shocks on the car appeared to be original and the car has 280,000 miles on it so a new set was definitely necessary. We found the best price for the Bilstein shocks on line at AJ-USA and I ordered them on Monday morning.
I used these instructions I found on Miata.net http://www.miata.net/garage/shocks.html to remove the rear shocks. They came out easily.
I started removing the front shocks, but stopped after removing the lower shock mounting bolts. I will need to decide how to proceed based on the suggestions listed.
I did look at using a spring compressor with the shocks still on the car as suggested on Miata.net, but the OEM Spring Compressor I bought at Autozone will not fit while the front shocks are still on the car.
So, I decided to remove the ball joint and get some help to push down the A-arm. That can wait until this weekend.
The shocks arrived today (Friday 2/1/2014) despite the snow storm that crippled Atlanta, but the bump stops have yet to be delivered. Hopefully, they will be here this evening.
Matt came over Saturday morning and we finished removing the shocks. All that was left to do was to separate the upper ball joint and remove the shock.
First, we removed the two bolts holding the brake caliper and moved the caliper out of the way suspended on a short bungee cord. Then the cotter pin was removed and the castle nut loosened about 1/4". Leave the nut on the ball joint to protect it for the next step. Next the ball joint is separated as described below.
We have found that two 3 lb. sledge hammer struck on each side of the casting where the ball joint is mounted in will cause the ball joint to just pop out. The trick is to smack the part with both hammers at the same time. It only takes one smart lick with both hammers arriving at the same time to make it happen.
Only problem is that it is very difficult to swing the hammers under the fender and getting them to strike together takes many attempts. Your arms may fatigue before it pops, but it will work. I turned the wheel to the left to get more room on the driver's side to manage the hammers. This resulted in fewer attempts after I turned the wheel since I could control the hammers better. Both sides were removed this way.
I tried just one hammer smacking the part, but never had any success that way. You do not have to over do it and try to break the parts. I have also tried to strike the nut to get the joint free. All I have ever accomplished that way is to ruin the nut, or worse, damage the threads.
The locations to strike are under the upper A-arm and on the casting holding the ball joint shown by the two arrows below. Do not strike the A-arm or the brake parts!
Now Matt pushed the front lower A-arms down with his foot while I pushed down on the upper A-arms and removed the front shocks.
The FCM bump stops we ordered arrived just after all the shocks were removed. What luck! Now we could finish the job.
We marked the orientation of the top of each spring to the perch before Matt and my oldest son, Justin, used the spring compressor and removed the old shocks and installed the new ones. We also installed the new FCM bump stops and reused the old dust boots.
Once Matt and Justin had the first shock ready, I started re-installing them. Just reverse the steps listed in the instructions from Miata.net. Be sure to torque the bolts properly.
This is how the car looks the new shocks installed.
I forgot to mention that the springs were sport springs. Now that the Bilstein HD shocks have been installed, the Rallycross Miata rides like my 1999 AE.
We are now ready for another Atlanta Region Rallycross on 02/09/2014 at Durhamtown Plantation Sportsman's Park. I hope the weather cooperates.
I sure do enjoy Rallycross!