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Discussion Starter #1
Well, it finally happened. We all knew it was coming. Too many drag pulls have took its toll on my flex plate and it finally cracked. Still moves, but damn is it noisy! At idle it sounds like the engine is falling apart. In reverse or under load the sound goes away. A peek inside the converter access cover reveals a crack and much louder noise when removed.

Anyway, main point of this thread is to ask if anyone has seen an upgraded flex plate that is supposed to be more durable. I'm open to aftermarket and swaps from other vehicles as long as everything lines up.
 

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No upgrade as far as I know.

You should know already, manufacturers usually doesn't offer warranties if used for racing. When my first flexplate broke, the new one lasted about 30 days, then the next one another 30 days. The last one still working fine.

I don't do drag racing (not on this ugly brick, have other vehicles for racing), but I do a lot of heavy trailering.

When I started drag racing, I learned that parts are installed and upgraded to "win that race", so now I know parts doesn't last very long, you should be ready to keep replacing parts.

If you ever find a stronger flexplate, better find an stronger transmission too.
 

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Discussion Starter #3
All so true. Trans upgrades are in the works. Plotting out what I need and saving up. Probably going to find a low miles used one and upgrade it myself, but the Jasper reman looks tempting.

Strange that with this being a fairly common failure that there isn't a supersession after 4800696AA.

As for drag racing the van. I prefer an all purpose vehicle for all of my needs. Plus the shock factor when little coupes get chopped by a van is pretty nice. Not recommended for people not wanting to do a bit of modding and extra maintenance.
 

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I've wondered if "doubling up" the flexplate is a possibility. Usually there is some room after unbolting the torque converter, to push it into the transmission a bit more. Why not use that extra room to put a second, modified flexplate on? One that only goes out to the torque converter holes and fits inside of the tone ring. Use a little longer bolt on the torque converter and crankshaft to make up for the added thickness. Just an idea I had after reading the last broken flexplate thread. This is too much of a common problem with these vans, so about time someone tried to fix it (since Chrysler never will).
 

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There must be a misaligned part somewhere causing what appears to be fatigue cracking.
Hank
 

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Discussion Starter #6
I've wondered if "doubling up" the flexplate is a possibility. Usually there is some room after unbolting the torque converter, to push it into the transmission a bit more. Why not use that extra room to put a second, modified flexplate on? One that only goes out to the torque converter holes and fits inside of the tone ring.
I thought about the possibility of doing something sort of like that. Going all the way to the ring gear would make the plate too rigid and not allow it to flex at all. But I think if you were to do that, but only to the edge of the relief holes it might strengthen the common failure area enough without sacrificing flex.

I'm going to get a new one, but I might pick up a used one later on and reinforce it as a backup. I figure I can weld my broken one back together and cut out its center to use as the reinforcement. They always say welds are stronger than the metal they bind.
 

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I think you're on to something there! Basically increasing the spring tension of the steel plate, but not too much (as in doubling it). I did try to clarify out to the tone ring, not ring gear. Basically just past the holes for the converter. That might have been overkill though.

One other thought, is that the engine-to-transmission mating isn't strong enough and the flex in that area makes the flex plate flex TOO much, resulting in all these failures. Toyota likes to use cast iron stiffener braces that bolt to the lower sides of the block, and curve downward and bolt to the bottom of the bellhousing. When I was pulling the engine from my 2001, I noticed the bottom of these engines don't have that. Maybe the 3.6 does? It's been 3 years since we had our 2011 5th gen and we didn't even have it for 2 years so I didn't get too familiar with it. Anyway, if the engine and transmission are always flexing downward where they meet, the flex plate is "working" more than designed and prematurely failing. Maybe the bellhousing bolts loosen a little, or become elastic with heating and cooling? Might be a good thing to check the torque on those once in a great while.

BTW, saw your thread on the coolant bypass/thermostat housing upgrade. Nice work!
 

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Discussion Starter #8
Another thing that I thought of was if a flex plate were made that had more smaller reliefs and several more "spokes". That's if spreading out the flex more gently might help.

Your ideas on bellhousing shifting might have some merit. The front and rear mounts are situated directly at the point of connection between engine and transmission. The rear mount bolts to the trans and front to the engine. This could definitely cause some torsional forces. Whether it does flex will require some looking into.

Unfortunately the coolant crossover mod was not necessary, since the Dorman prototype I had been hunting for finally made it to production shortly before I did it. If I had known it was finally available I would have gone that route to keep the extra clearance on that side.
 
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