daking Posted December 13, 2015 Share Posted December 13, 2015 So, stated driving the jeep a bit more. Started to hear knocking, like rod knock. Sucked, cause its a new stroker with less then ~500mi. Some research showed a common mis diagnosis of rod knock turns out to be cracked flex plate. So, I removed inspection plate on the transmission, and used a "snake camera" attached to my cell to look at the plate. And sure enough, there is a fresh crack. From center going to a hole. And some other spider cracks. This good news, as its not the engine. Bad news, though, cause the damn transmission was just installed 3 weeks ago. I always use failure as an opportunity to upgrade. I can't find any performance flex-plates for the Jeep AW4, like billet. Anyone ever see any performance ones? Image Not Found Image Not Found Link to comment Share on other sites More sharing options...
HOrnbrod Posted December 13, 2015 Share Posted December 13, 2015 Bummer. Was that a new flexplate? And no, I've never seen any performance flexplates for the AW4 / A340 transmissions, and I've looked. Link to comment Share on other sites More sharing options...
gogmorgo Posted December 14, 2015 Share Posted December 14, 2015 I'm not sure you'd want anything other than the oem one. The flexplate is already pretty light, and there's not much material to remove. Since it is intended to flex a little (to make up for slight engine-trans misalignments, hence the name) I don't think you could switch to any of the common lightweight alternatives to steel, such as aluminum, because of the reduced fatigue life. Going up a a few grades in steel quality would reduce its flex and possibly decrease drivetrain losses by a smidge, but would also increase wear on the crankshaft and trans input bearings. Of course I could be completely off base. Link to comment Share on other sites More sharing options...
daking Posted December 21, 2015 Author Share Posted December 21, 2015 pulled the transmission. The plate was totally broken. I'm surprised it lasted as long as it did. What sucks, I just paid a transmission shop to rebuild my Transmission. You would think they would have seen the cracked plate. I have to spend a weekend worth of time pulling and reinstalling a transmission to replace a ~$40 part. Image Not Found You can see where to converter bolts wore loose. most likely causing the failure. It was making the noise before the transmission rebuild, I may not have torqued em when I installed the transmission last year. Image Not Found Image Not Found Link to comment Share on other sites More sharing options...
gogmorgo Posted December 21, 2015 Share Posted December 21, 2015 I've heard people say that you shouldn't reuse the bolts, although it apparently has been done successfully. Judging by the torque spec, (120lb-ft + 90 degrees, iirc) I'd guess that they are torque-to-yield bolts. I reused them after swapping my cracked plate out, but that motor only went another 5000 or so miles after that. About a month before I noticed my cracked plate making noise I had the engine out (a couple bellhousing bolts broke off/stripped the holes), and the shop must have hunted for anything they could possibly up-sell (they recommended an extra $1200 in work) in addition to inspecting everything for damage caused by driving without the engine bolted to the trans. They also missed my cracked plate. Link to comment Share on other sites More sharing options...
daking Posted February 23, 2016 Author Share Posted February 23, 2016 Well, SOME BEACH!@ Less then ~30 starts. Brand new ATP Flex plate.... Guess for a 3rd time in just as many months the transmission is coming out.... $@#%%#$^% Image Not Found Link to comment Share on other sites More sharing options...
Tanner Posted February 23, 2016 Share Posted February 23, 2016 Well, SOME BEACH!@ Less then ~30 starts. Brand new ATP Flex plate.... Guess for a 3rd time in just as many months the transmission is coming out.... $@#%%#$^% Image Not Found I feel your pain brother, I have pulled and reinstalled mine 3 times in the last two months for various reasons as well. I'm investing in a trans floor Jack at this point haha. Link to comment Share on other sites More sharing options...
ftpiercecracker1 Posted February 25, 2016 Share Posted February 25, 2016 Well, SOME BEACH!@ Less then ~30 starts. Brand new ATP Flex plate.... Guess for a 3rd time in just as many months the transmission is coming out.... $@#%%#$^% Image Not Found What the hell? How could that have happened? Any ideas what went wrong? Are they going to warranty it? Link to comment Share on other sites More sharing options...
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