why would my 523 destroy 3rd gear?

[OmniLuvr]

so ive been driving around my SC for 6 months now with no issues, slowly turning up the boost and messing with cals. ive got a 90 523 small spline with the 3.50 final and a centerforce clutch mounted to a 2.2 cb with t3 pistons, a stock g-head, 89 tbi cam, heavily ported 2 piece intake and log manifold, +40's, s60 turbo, and im running it on e85. ive been running 18 psi for the past 2 months and decided last night to turn the boost up some more, but i never made it that far.

after picking up the chip from my friend i wanted to have a good back to back test, so i went to my favorite on ramp and let it rip, wot at 2500 rpm in second to redline, shift slowly, let the car slow down slightly, engage the clutch and once i reach 3k i hit the petal to the metal, boost kicks in and it sounds like i just lost my bottom end on the freeway. i push in the clutch and drift to the shoulder but realize my engine is still running? put it back in third and the car shakes and grinds, put it in fourth and all is well (kind of, you can still hear 3rd making noise).

so im trying to figure out what may have caused this, because i thought this trans could take the abuse, and i really dont want it to happen again. i would have thought that the centerforce would have let go before the the trans, so any info would be appreciated. also, there was no grinding or other issues before this, i am very hard on my cars, but i build them for battle so i can beat them, whats the next step?

[shadow88]

A couple ways to look at this..

More than 18psi is probably exceeding the designed input of the a-523 so it was just a matter of time. I thought I read the suggested prolonged input torque rating was 200 foot pounds. We all know they're capable of more, but how much more, and for how long?

The ceterforce clutch is probably newish and built within the last 3 years. The a-523, on the other hand is 22 years old.

How about once it's torn down and you snap a few pictures, maybe the underlying cause might be found, or maybe it's just time for it to expire after 22 years.

[Lotashelbys]

I have had this happen before to me on a few of these transes. The gear teeth are very small on the early 523s and no where near as strong as the 568 gears so its very possible to strip the teeth right off. Thats exactly what happened to yours im sure. Time to find an 89 555 or 90 568 and swap out the input shaft and speed gears......

[OmniLuvr]

Thanks, I wasn't sure if the 523 had smaller teeth or not, I have a 91 523 that needs a diff and a ring gear, guess it'll get donated from this trans. Also my friend might have a 93 or 94 523 with a 3.77 ratio, would that be a better candidate than the 91? Strength wise?

[Lotashelbys]

Yes 92+ 523s are stronger than 90-91s

[OmniLuvr]

That's an awesome bummer, good because I have the 93 523 now, sucky because the two 523's I have are only good for hybrids, or are they even good for that? Will I be able to get either of the 3.50 finals (90 & 91) to work in the 93 523?

[135sohc]

Will I be able to get either of the 3.50 finals (90 & 91) to work in the 93 523?

Sure you can. The parts are fully interchangable for what your wanting to do.


Just for fun, here's an early 523 input vs a 92+

[OmniLuvr]

thanks for the replies guys, got me back on track, now i know, and knowing is half the battle...

[turbovanman²]

lol.

[Ondonti]

I would say worn out leads to the failure that only happens when larger amounts of power are applied. Too much slop in the bearings and the shafts are allowed to seperate more and then the weaker teeth unmesh and chew up.

[OmniLuvr]

it was a jy tranny pulled out of a 90/91 daytona shebly (2.5), had 126k, didnt really make any noise while driving around or sitting at idle (ive heard some make the throw out bearing noise, but its not that bearing), but i also just slapped it in, needed the car on the road bad. im sure it was making some good trq with the e-85 and the higher compression, and it didnt help with my persistant beating on it, i just didnt know if they had the same problems like the 525/520/555 trannys. i thought the only difference between the 568 and 523 was the diff being bigger, and integrated into the ring gear.

if i had done more research and had more time, i would have taken better precations in building the trans correctly, and wouldnt have turned the boost past 14psi, because it "felt" as strong at 14 than my other engines ive built at 18, never had time to dyno or take it to the track (even though it was going to the track the day after i blew out third).

good times, il try to get pics, but its not like ultimate carnage, the other gears still work...

[trannybuster]

Sucks doesnt it! As soon as you think your bullet proof, it aint so......kinda like the intermediate timing/pump shaft. Good trans hunting.....

[Ondonti]

I am referring to the two stacks being allowed to separate because they need to be reshimmed.

[Spycker]

Im guessing my 1991 A523 wont be able to take no more than 400HP beating?