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Old May 4th, 2013, 14:35
DanMan2k06 DanMan2k06 is offline
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Cracked flex plate? Now bent flex plate???

1998 - AW4 - 231 - 90,000 miles - Ok here's the scoop. Picked up a new Jeep super cheap from a small up and coming shop that seemed to be cherokee enthusiasts. When I bought it, the seller told/showed me there was a noise, and leaned REALLY hard towards a cracked flexplate or something transmission related.

Got the Jeep home, started it up, and the noise sounded EXACTLY like serious rod knock. Towards the back on the block, so maybe it was the TC bolts or a crack? Or cylinder(s) 5/6 knocking? Checked all the TC bolts, tight. Checked for any cracks, couldn't see anything. Did some basic engine diag and came up empty handed. So I dropped the oil pan and all the bearings, looking for any destructive evidence. With such low mileage I found it hard to believe something engine related would have gone wrong so soon. Reassuringly, everything on the bottom end was fine.

Decided to pull the trans. One that was out I could see the the flexplate was not only cracked, but it was completely broken. The center section that bolts to the crank had completely broken away from the remaining part of the flexplate. I've never seen this. I'll get a pic soon.

Got a new flex plate and threw it in. Along with all new bolts, and a new spacers that sits in front of the flexplate. Now when I start the jeep, there's a horrid noise of the starter skipping teeth on the flexplate. With someone under the jeep and the cover off, we can see that the flex plate isn't spinning true. It's "wobbling", like too much runout. When a certain part of the plate gets around the the starter, there's not enough engagement to keep it moving and the starter skips. I figured maybe the shaft on the TC is bent, causing the flexplate to also bend. So I disconnected the torque converter bolts, and pulled the injector plugs so the jeep wouldn't start. The flexplate is still spinning crooked, and still skipping teeth. Could I have gotten a warped flexplate from the get-go? Could the end of the crank be warped? The palte was seated and torqued properly. It's a rock auto special, so I was weary from the start.
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Old May 4th, 2013, 16:55
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ParadiseXJ ParadiseXJ is offline
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Re: Cracked flex plate? Now bent flex plate???

If you haven't driven it any extended period, gotten it hot etc. and you're dead sure that it's installed correctly, and the torque converter is seated properly, then yes. It's entirely possible that you got a bum flexplate.
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Old May 4th, 2013, 17:00
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kastein kastein is offline
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Re: Cracked flex plate? Now bent flex plate???

There have been some shitty runs of flexplates recently... I know for a fact there was a bad run of renix ones, didn't know there was a run of bad OBD ones however. Yikes.
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Old May 4th, 2013, 20:19
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four_shot four_shot is offline
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Re: Cracked flex plate? Now bent flex plate???

Tug the trans and double check the flex plate to crank connection.
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Old May 5th, 2013, 08:50
Talyn Talyn is offline
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Re: Cracked flex plate? Now bent flex plate???

Quote:
Originally Posted by DanMan2k06 View Post
Got a new flex plate and threw it in. Along with all new bolts, and a new spacers that sits in front of the flexplate.
Where did you put this spacer? Its crank, flexplate, "spacer", bolts. But I still think you have a faulty flex plate. Was it a dealer item?
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Old May 5th, 2013, 08:55
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kastein kastein is offline
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Re: Cracked flex plate? Now bent flex plate???

It's actually a large pressure spreader/multi hole washer I believe, not a spacer - but either way, I agree with Talyn, it goes over the flexplate and under the bolt heads not vice versa.
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Please do not PM me about the AW4 info thread unless you have a truly unique question that is not covered by it or info to add. I do not respond to questions answered by the thread.
Definitely do not hunt down my phone number at 3AM, text me about it, and then threaten violence when I am not helpful. It will not get you what you want.
CTeunuch: Sometimes I really wonder if this sport makes you insane, or it just attracts the mentally unstable.
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Old May 5th, 2013, 19:14
DanMan2k06 DanMan2k06 is offline
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Re: Cracked flex plate? Now bent flex plate???

Yes, that's how the spacer was installed. I made sure to triple check it before torquing the bolts down. My logic is that if it was a bent input shaft or something of that nature, the trans would be making a TON of ruckus. It's an aftermarket flex plate. Sad part, as I just found out, is it was more expensive than an oem one. Oem is only $67. No trouble there, I just hate pulling this jeep trans in the driveway. I pulled the inspection cover on my '99 to see how it looks when running, and it spins straight as an arrow, so something is definitely not right. Looks like there's no way around it
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Old May 7th, 2013, 15:31
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Locked98GC Locked98GC is offline
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Re: Cracked flex plate? Now bent flex plate???

My trials and tribulations.

http://www.naxja.org/forum/showthread.php?t=1081459
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Old May 7th, 2013, 20:22
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Ecomike Ecomike is offline
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Re: Cracked flex plate? Now bent flex plate???

Quote:
Originally Posted by kastein View Post
There have been some shitty runs of flexplates recently... I know for a fact there was a bad run of renix ones, didn't know there was a run of bad OBD ones however. Yikes.
China quality just seems to be going from bad to worse. I did a plumbing job 2 weeks ago, 2" schedule 40 galvanized steel pipe (way over priced too), and had 4 leaks, each at a union. Pulled the unions out and every one was an obvious machining error on the di-electric sealing faces. Never seen such poor craftsmanship. Reminded me of the brand new off center, by 1/4", brake drum I got 3 years ago.

I had not seen it in plumbing pipe before. There was no possible way those unions could ever seal.
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