TurboIIGuy

hey whats up everyone?
I got a 1985 RX7 12A and I just picked up a lightweight steel Racing beat flywheel from a buddy of mine. He never used it so I am not sure how to install it. I'm pretty good with cars, I work on all my cars myself but have never had to pull off a flywheel to swap it for a light steel one before. I have the flywheel and the automatic tranny counterweight that racing beat says i need. But what now???
I have the socket to remove the flywheel nut but how do I keep the flywheel from spinning while I am trying to remove the nut? I am going to be swapping the flywheel while the motor is still in the car. Also what do I line the counterweight up to? does it go on in the same position as the one I am taking off? Also does it matter that the counterweight is from a S4 RX7 with an auto tranny???
I know I have a lot of questions, I hope someone can help. I did a search but couldn't find anything helpful.
Thanx in advance.

inittab

What you need is a flywheel stopper. There are probably other methods of holding the flywheel but you risk damage and injury. Good luck!

frode

You have to get a rear counterweight for a 85 12A. The S4 13B one will fit and work, but you will disurb the balance of the rotating assembly.

The counterweight is hold in place on the eccentric shaft with a key, just like the old flywheel. I would get a flywheel stopper like inittab suggested, that will make the install a breeze.

--
frode

coldy13

To hold the flywheel in place you can use a piece of 1/4" steel plate, about 6" long and 1 1/2" or 2" wide is perfect. Just prop that between the counterweight and one of the recesses in the back plate and it'll hold it good.

Pele

iTrader: (28)

Measure between two clutch plate mounting holes... Be sure the measurement doesn't cross the center.

Get a long steel bar or pipe... The pipe should be long enough so that when one end is on the floor, it reaches the height of the top of the flywheel when your engine is on your engine stand. If the flywheel is on the top of the engine and the engine is being disassembled vertically, slide the engine stand over to a pole or some other unmovable structural object...

Drill two holes, that exact spacing measured above in the bar or pipe... One holes should be near the end.

Get bolts that fit the flywheel... Bolt your long rod to the flywheel, prop the rod against the floor or some other unmovable object as stated above...

Fire away with the impact... Or tie a functioning car to a breaker bar and use the car to pull the breaker bar... Spec on that flywheel nut is something ungodly like 350 Ft/lbs.

coldy13

Tie a car to it!? Just a little extreme don't ya think? I've always used a 4'-5' torque wrench to take it on and off. I don't have much trouble taking it off and putting it on. I had the engine sitting on the ground(no oil pan) and had someone else hold the engine still with a big pipe where the dizzy goes in the front cover while I tightened the nut.

Jeff20B

iTrader: (13)

After you install the correct counterweight ('83-'85 12A), you'll want to align the two alignment bolt holes in the flywheel with the woodruff key on the counterweight. you'll also want to align the pressure plate's two smaller holes with the two alignment bolts. There is sometimes an O or a circle stamped near one of the alignment holes on the pressure plate.

TurboIIGuy

Ok, all great info, now I understand ore or less how to do the whole thing. Since I'm not to far from Mazdatrix will be buying a flywheel stopper from them. But does anyone have pix of the orientation of the counterweight and the flywheel when it's being installed. Jeff20b said "you'll want to align the two alignment bolt holes in the flywheel with the woodruff key on the counterweight. you'll also want to align the pressure plate's two smaller holes with the two alignment bolts." Any pics of this. Once again thanks to all the info from everyone, it sure as hell got me going in the right direction. I just want some pix so I don't start this and then freak out if I'm not completely sure what needs to be done by visual association.

Jeff20B

iTrader: (13)

The two alignment bolts are just two out of the six that hold the pressure plate on the flywheel. As for the six bolts that hold the flywheel to the counterweight, they're all the same. If you look inside the center hole of a counterweight, you'll see a notch. Align the notch with the alignment holes in the outer circumference of the flywheel.

TurboIIGuy

Ok, it all sounds about right to me now. I have a RX7 repair manual so I was looking at the pix. I know how to work on cars but I've never replaced a flywheel with a lightweights. Thanx for all the info. I'm going to try and do it this week. I'll post after it's done.

BadAssRX-7

i hae done quit a few clutch/ flywheels and light flys. i finally went on and got me a 3/4" impact 2-4 "whacks" and off the nut goes. i rember the hours i spent locking the flywheel and getting a long thing of pipe on my socket and man that sucked. air tools are your friend

Todd Staples

A GOOD 1/2" impact should get the nut off if you have a good compressor. I removed mine last weekend, About half a dozen whacks and tightening the puller bolts and it was off. I had to replace the rear seal. I would recommend replacing the seal while you have the flywheel off. They are only about $9 and you don't have to worry about it later.
TCS

Pele

iTrader: (28)

Air tools rock... I love my Snap-On 1/2 / 3/8 inch (Removable end piece. The gun actually has a splined socket, so I can change square drive pieces.) impact gun...

It's my dad's ******* piece of **** 4 gallon 1/2 HP air compressor... Three or four wheel lugnuts and it's gotta refill the tanks... To get ANY torque out of my gun, I've gotta crank the regulator up to 125 PSI... The gun is supposed to run 90-100 PSI.

mcnannay

i have the same snap-on air impact gun, it freakin rules, i've never even had to lock the flywheel to get the nut off, just spins right off after about 3-4 seconds of "impacting"

the real bitch is the eccentric shaft bolt, thats a big pain in my ***

Jeff20B

iTrader: (13)

I guess I'm lucky I haven't had a problem with my 19mm bolts yet. My 2 1/8" 6 point impact socket works great too.