drittens

How thick was the stock spacer? My spacer seems to be close to 15mm but at
http://www.mazdatrix.com/b5.htm
they are all in the 8mm range

kenn_chan

as you know there are various sizes depending upon the amount of your endplay sounds like your engine has had the sides lapped once or twice, and maybe even a seriously frankensteinish non-standard rebuild using parts from various models to get a 15 mm spacer. the main thing is that when assembled you must measure the end play with a dial guage and purchase accordingly. I would assemble the motor and then check, chances are with a new set of thrust bearings your end play will probably be fine with the same spacer, (providing you didn't get the side housings lapped) but you will never know without putting it togethor first and measuring it.

kenn

trochoid

iTrader: (6)

The FSM and the Haynes list the stock spacer sizes and thier corresponding letter designation. 15mm sounds like something is way out of range.

Could you give more detail? Is this a new rebuild?

drittens

I got this engine with a supposed 70k on it(no rebuild) as a cheaper way to get the 7 running. I just remeasured it again...I wasnt thinking and said it was about 9/16 not 5/16 like it actually is(stupid mistake huh?) . Not thinking about end play, I pulled off the flywheel and front balance and replaced them with mine. When I put it back together, I checked the end play because there felt to be quite a bit - .032. I made sure the flywheel was on as far as I possibly could...there is a bit of thread beyond the nut(like shown in the Haynes manual). Should I jsut put it back together like it is or should I mess with trying to tighten it up? The thrust washer(I think #2 in the Haynes manual) is jsut a little too think to get rid of the gap the end play makes.

trochoid

iTrader: (6)

Had to get out my Haynes for this one. In figure 1.21 of my Haynes, P. 45, item #7, the spacer is what sets the end play. That spacer has a letter on it. Compare the spacers between the 2 engines. You may need the spacer that went with the old one.

I hope your 0.032 end play was a typo. 0.0035 is max end play.

As an odd thought. Are you using 2 of item #3. The old ones tend to stick in the counter weight and can look like they are a part of the counter weight itself. That may account for the large amount of play.

custom13B

Jlindustrialtools .com has cheap magnetic bases and dial indicators to measure end play. Mazdatrix stocks the spacers and I dont believe thier too expensive. I ended up ordering several sizes and just measured and used the one that gave me the disired end play. You really need a dial indicator for this as its important.

drittens

The spacer has a Y on it. I've got some dial indicators - my dad and I used them when we were installing new innards for my old 66 GTO's rear end. Unless I'm reading it wrong, yes it is .032. My dial reads in .001" and it moved from 0 to 32.


OK! I just went and put everything back together really carefully this time and the ghastly endplay disappeared!(just a hair over .001 now) I think what happened when we were putting it back together we left out the thrust washer(the one that butts up against the counterbalance). Thanks for all of your time and input....I'm sure I'll be calling on it again before it is all said and through.

One things for sure though....my first ride in an Rx-7 will be one of the most gratifying experiences ever! (This is the first and only Rx-7 I've ever even sat in)

trochoid

iTrader: (6)

Good to hear you got it sorted out. I was wondering if you had an extra piece, or missed one in the assembly. It took me the longest time to get the first one right.

custom13B

Me too as these engines are different than anything else. The How to Modify your RX-7 book has great pictures on this endplay and assembly. Any RX-7 owned should have that book IMHO. Its out of print so check ebay for it. Good luck