Description of 1st Generation RX-7 ('79-'85) Front End Workby Scott Lelievre
A word of warning when it comes to RX-7 front end work. If you need to replace just about any part of the suspension you'll need to almost entirely disassemble the front suspension. Examples are: To replace the sway bar you'll need to remove the tension rods and the sway bar/tension rod mounting bracket. All of the bolts are very large and very stubborn to remove. If you've got the tension rods out, you might as well put new bushings on there now. If you are going to replace the lower control arms you'll need to remove the sway bar endlinks, tension rods, strut assemblies, tie-rod ends. Also if you live in the rust belt like me, every one of these parts will be almost impossible to remove without breaking or stripping half the bolts in the process. Enough ranting heres the more involved description of everything I did to the front end:
I replaced the lower control arms with new ones from Mazda. They have poly bushings in them now. To press out the rubber bushings I used a vice. I put a socket large enough for the bushing to fit in on one side. Then I used a smaller deep socket to push the bushing through the arm. So basicly, I have sandwiched it in the vise: a large socket - control arm - small deep socket. Then just tighten up the vice. The poly bushing pressed right in with the vice and no "special tools" were required.
Replaced all the tie-rod ends and idler arm. This was actually pretty easy and straight forward. Just remember to get an alignment when your done!!!
Replaced the springs and struts. These were a pain in the ass!!! I fought way too many rusty bolts here. There are two bolts that hold the strut assembly to the steering arm. On both sides, I broke one bolt and stripped out the other. I had to use a 1/2" ratchet with a 6' "persuading" bar just to move the damn things. I also heated and sprayed them down with penetrant. I figured I'll have the strut tubes repaired at the local machine shop, no big deal.
Put in poly bushings on the tension rods. Another pain job. The nuts holding the tension rod to the bracket are huge. You'll need to go out and buy two wrenches to fit these. It will make the job much easier. My bushings were way gone all cracked and nasty looking. I started by removing the tension rod from the lower control arm. Then removed the front/outer nut to get the tension rod seperated from the bracket. Then I found that because my bushings were gone, the bracket had worn into the tensions rods. So again I got some used parts from good old Cali. When reinstalling these Mazda specs out there should be .423" +/-.039 of tension rod sticking out past the nut and the nut torqued to 100ft lbs. The trick here is getting the back nut in the right place so that when you have a 100ft lbs on the front nut you have the right amount of tension rod sticking out. A bit of pain but not too bad.
Put in a suspension techniques sway bar. This seems real easy at first but here are the catches- You must remove the mounting brackets from the body. This involves also removing the tension rods. And of course you have to take out the sway bar endlinks. The kit came with new endlinks, so if you break these removing them, no big deal.. Now here's where you learn from my mistakes. Install the sway bar bushings and the bushing retainer/bracket before putting the sway bar/tension rod bracket back on the car. I didn't try to put the bushings on until I had the thing 3/4 of the way back togethor. It took some persuassion and disassembly to get them on when you screw up like I did. Be sure to grease the bushings with some teflon based grease. Also another thing I like to do is cut the endlinks to length so that the bar sits parallel when the car is sitting on the ground. I believe the bar doesnt work as well when it's away from the flat position when installed.
Replaced the brake backing plates. My backing plates had seen better days. They were pretty rotted and holey. I bought new ones from Mazda for something like $35 a piece.
Repainted the calipers. I sandblasted then painted my calipers. I used plasti-kote (available at Pep-Boys everywhere) 500deg. engine enamel. The stuff sticks like nobody business and should hold up well to the brake heat.
I sandblasted and painted everything else. Everything else that wasn't replaced was sandblasted and then primered with a 2-part epoxy primer then painted gloss black. The list of stuff done like this was: engine cross member, brake caliper brackets, swaybar/tension rod bracket, tension rods (remember to cover the threads when painting),.
So now the whole front suspension either is brand new or looks it!!!
written by: Scott Lelievre