I'm building a T2 motor (s5 irons, everything else is s4 and from the old motor rebuilt 5k ago) and my endplay reading is like 30 thousandths of an inch! The motor had been rebuilt like 5k ago with new stationary gear and rotor bearings. But those don't affect endplay right? Did I install something wrong, or what do I need to replace? Is it because I have s5 irons with s4 everything else? I have been following the FSM procedure and have been using the Bruce Turrentine video as reference.

I can feel the slop as I pull up on the counterweight with a prybar to read the endplay. On the front side I had the spacer, needle bearing, thrust washer, counterweight, and then the two drive gears. I know I didn't pinch the front needle bearing because that's unlikely with the motor out of the car and it would also result in zero endplay. The front bolt was torqued to 80 foot pounds and I even double checked it. I have the clutch and flywheel installed with the flywheel nut tightened by my air impact gun on full torque.

Should I just get a new thrust washer, "V" spacer (I thought most engines used V spacers from the factory), and needle bearing? Or could something else random be wrong? Nothing seemed to obviously be in bad shape when I pulled it apart, and there are no thickness specs for the needle bearing or thrust washer. A friend of mine was helping me a while back and he installed my front stationary gear from my old front iron to my new s5 front iron and i presume he installed the thrust plate and other stuff correctly. I know he torqued it down. But all the stuff behind the thrust plate doesn't affect endplay does it?

Thanks for any help. I just want to order whatever brand new OEM parts I need to get this motor together correctly.

 

Usually when there is too much endplay, you have worn needle bearings. Once you install new bearings, check the endplay again. If it is still out of spec, then buy a spacer that will get you in spec.

 

i pulled off the thrust plate and the rear needle bearing was crushed due to improper installation of the spacer.

 

^ good luck i will be doing the same one day.

 

We see this all the time on failed DIY builds that are sent in for re-rebuilding, most people don't catch the proplem before they install the engine and run it, which creates all kinds of problems...

 

Well that would to it.

Also keep in mind that you only need to apply moderate pressure with the pry bar. All the pictures make it look like people put all their weight on it, but that's not true. Put enough weight on it and the plates start to deflect giving an artificially large reading. Just a firm pressure with one hand is enough.

 

Good job figuring it all out!!

CAnt wait to do my first one.

 

FWIW,

When installing the front stack, keep the engine vertical the entire time. It'll minimize the chances of things getting out of order/pinching. I've been close to having that happen before....

 

Been there, done that, seen the aftermath first hand. Good luck getting it back together. At least you didn't do what I did and run the engine all summer like that. I didn't build the engine though so I can pass the blame.

 

i do not necessarily agree with keeping it vertical but everyone has their own personal preference, my preference is paying attention and not pushing or pulling on the shaft before tightening down the front e-shaft bolt and use thick oil or vaseline to keep things stuck together.

 

It's interesting. When you pinch the front needle bearing, you are supposed to get zero endplay. When you pinch the rear needle bearing, you get a crapload of it. Oh well. $12 lesson (Malloy Mazda ftw) learned. I am determined not to be that guy who threw his first motor together carelessly and then just gave up when it didn't run right. Oh and I didn't push too hard on the pry bar. In the Bruce Turrentine video he gives it some effort but doesn't exactly throw his body into it.

Just out of curiosity, what would have happened if I had run it with that bearing crushed and 30 thousandths of endplay?

 

Well, if it gets as bad as mine did, the front counterweight will start hitting the front cover when you push the clutch. The oil pump will be scored badly, and there would be a lot of steel shavings in the oil pan. My engine completely ate the rear torrington bearing and the washer started wearing away the retaining plate. The retaining plate actually cracked in about 4 or 5 places. It made for some nice carnage. There are some pics on this thread:https://www.rx7club.com/showthread.p...+Shaft+Endplay

 

worst case scenario would be a siezed motor with about maybe more than half usable parts. best case scenario would be if you ran the motor it would just need half a new front bearing stack and an oil pump, and fresh oil filters every 500 miles for about 3-5 oil changes using decent filters(OEM), alternately you can flush out the oil cooler if you can find a shop to do it. you might get severely lucky and none of the debris having gotten sucked up by the oil pickup tube though but i would check the pump and be weary of metal in the system anyways.

 

I had to replace the entire front stack pretty much. I also replaced the oil pump with a TII pump and the pressure regulator. I cleaned the oil pan and pick up tube, flushed the cooler, and built new cooler lines.

 

Well, this is starting to turn into a mess.



I ordered a new needle bearing from Mazda for an FC. That's on the left there. But that doesn't match the needle bearing that was in my car, the one there on the right. Is that an FD needle bearing? Or aftermarket of some sort? Whatever it is, the edge is shaped differently (almost like a bevel to it) from the one I just bought and it is noticeably thinner. Now I am beginning to question what kind of mix-and-match game somebody played with this motor. In its last incarnation it was professionally built by someone reputable whom I will not mention. But the professional builder was rebuilding a very short-lived motor that had spun a rotor bearing due to a timing problem.

I've got a Y spacer on there right now. What are the odds that the thrust washer or that other washer thing (behind the thrust plate) are somehow FD parts or something?

 

I may be wrong on this so if someone actually knows correct me if I'm wrong. I noticed the same thing when I ordered new bearings from Mazda for my engine in the fall. I just thought that Mazda redesigned the bearings, or possibly replaced the FC bearing stock with the same bearing that they use in the Renisis. All possiblilites. If I were you, I'd assemble the front stack temporarilly with those new bearings and measure the endplay again. If it is close enough that with an available spacer it would be in spec, I'd assemble it and give it a try.

 

Dont worry MAZDA did change the shape of the bearing a couple of times,i have torn down motors with the new and old style bearings mix together and they ran fine,the FD bearing is bigger in fact all the front stack on a FD motor is bigger,thicker and stronger cause of the pull type clutch setup

 

Mazda has changed the bearings many times over the years. That one is an FC and it is fine. FD parts have a much larger ID and OD.

 

Left is S4, right is S5 (at least, thats what I've found in the various series engines I've torn down)

 

interesting. I ordered that bearing using the part number from the s4 parts fiche.

 

it may have been superceeded. I've just seen the smaller needle type in all of the (seemingly..) original S4 TII engine's I've torn down. The one on the right I've found in S5's though. Just an observation, I've never had to order any so I don't know exactly what they have to sell at this point.

 

I installed the new needle bearing (so I am mixing the two as in the picture I posted) and checked the endplay with the Y spacer I already had. It was about 1.75 thousandths of an inch, so very much in spec. I guess it doesn't make a whole lot of difference then.

 

How did u improperly install the spacer?

 

To clarify, a friend had transferred my front stationary gear from my old front iron to the new one. He also installed the thrust plate, the rear needle bearing, and the other thick plate thing behind that. Well I just dropped the spacer in on top without removing the thrust plate and verifying that the needle bearing would be centered properly on the spacer rather than falling behind it.

Mazdatrix has some pics of what can happen to a needle bearing. http://www.mazdatrix.com/faq/pulley.htm :

 

FWIW, it's good practice to install the spacer as soon as you can, then slide over the plates and bearings around it.

Add me to the list of those who find it easier to do these steps with the engine vertical (resting on the flywheel-clutch plate pins on a piece of wood).