net seven

I'm to that step on my engine, and I dont have the proper tools for measuring the end play. What should I use and where can I find it? How important is this anyways?

Judge Ito

Everybody hold a minute...... the problem here is not that he has to much end play. the problem is that he does not have enough. The larger the end play spacer the more end play you will have. The letter C is smaller then the letter D.. You need to try the letter E and you will be with in specs.

Judge Ito

This is very, I mean very important. If you do not adjust to proper end play, you will find engine bearing failure over a period of time. When engine parts heat up they expand and if there is no room to grow then the stationary front and rear main bearings will try to walk.. Porper end play is also a mod for reliability. I always run a little more then .0025 in all my engine giving the engine enough to room to grow (side to side) and not jam the front and rear main bearings.

Lynn E. Hanover

Well,



That is the point of the 400 paper. It lets you remove small amounts of material in a very slow operation.



So you had 0.004" end play with a 0.316 spacer. You needed to remove .001" from

the spacer, to get to 0.315" To get to 0.003" end play. In the zone for Mazda and Judge Eto.



You removed 0.003" to get a 0.313" spacer, or 0.002" too much.



Buy the right spacer.



Lynn E. Hanover

Lynn E. Hanover

You need a magnetic base stand, and a dial indicator. Harbor Freight tools. Less than $25.00.



The thrust bearings are cheap enough that they should be replaced, since it's apart anyway.



The bearings control crank end play. If you have a distributor or a crank angle indicator, excess end play alters timing. Too little end play can be reduced to zero when the crank flexes and fail a bearing. You can build the engine with zero end play, or zero with a bunch of preload, and the engine will run fine for a while, but the bearings will fail. Both bearings are used to locate the crank fore and aft.



The rear bearing takes the additional load of the clutch release bearing being extended to release the clutch.



Very important.



Lynn E. Hanover

93BlackFD

the mazda manual says "if the end play is more than specified replace the spacer with a thinner one, if the end play is less than specified, replace the spacer with a thicker one"



i was confused too but i was going by the manual



http://www.iluvmyrx7.com/3rdgen/manuals/93...copy;engine.pdf

pengaru

what ito said is right only after he removed too much material and got down to .001, he was too big initially.

Wargasm

Since we're on the topic of the front cover stuff....



I had an 87 TII engine spin the front and rear bearings after a few thousand miles. I believe that what happened is that I put in a very heavy duty pressure plate when I did the rebuild and the 15 year old front thrust plate in the front cover cracked because of this and let things move around too much.



When I took the engine apart, the front thrust plate that the thrust bearings ride on was split into two pieces! The needle thrust bearings were all messed up. It could be clearly seen that the side of the eccentric shaft rotor lobe had collided with the flat surface of the front iron plate... there were bad burn marks on the front iron all over the area inside the oil seal tracking marks. It was some major destruction!



Ever since then I always use a new thrust plate and I also recommend that people put the "upgraded" thrust bearing in there on an FC. Mazdatrix sells them. They are the same thickness, but they have more needle rollers in them to better take the load.



Brian

Judge Ito

Wait a minute it was to early in the morning when I read this thread. I think like 5:30 am and I must have been half a sleep. Ok your telling us that you got .005 of an inch then .004. That is five thousands of and inch and 4 thousands of an inch. way to much. Yes grinding down the spacer will make it smaller and giving you less end play. You tried the letter C and D .. D is larger then C, I would order the letter B and the letter A just to be on the safe side and try them and re-measure.

93BlackFD

went to rick engman's shop and let him inspect it, he ended up with a C spacer and the end play is .0030, that's perfectly fine



thanks for the help guys glad i didn't try to run it with .001 ;-)