Flex Plate recommendation, cool pictures

Jamie · Post by **Jamie** » Thu Nov 25, 2010 6:22 pm

Howdy. Car developed a chatter to it and it wasnt knock. Thought the trans that I Just rebuilt was taking a dump so I decided to go ahead and do the Manual swap. When I got the trans out this is what I found. Im lucky it didnt come apart and I stopped driving it when I did. Check these out...

So I obviously need something more than a stock flex plate. I do have a modular stage 4 clutch that is going on with the swap.

Is anyone running an upgraded flex plate, maybe one of the NHRA approved plates? I'm open for suggestions

JeffB#2 · Post by **JeffB#2** » Thu Nov 25, 2010 7:35 pm

It's actually not completely uncommon, especially in a 2.4 car for some reason. Normal cause is loose bolts that hold the trans to the engine. It's a stress crack that has worked it's way all the way around. If the trans moves in such a way that the center lines of the crank shaft and trans input shaft are able to move off-center from each other, it will set up a stress crack in any flexplate, stock or aftermarket. If they're not bolted together securely with zero movement, a crack can start. Once started it will continue to grow even if the bolts are later tightened up properly. A crack can also start for no reason at all, it just happens occasionally.

There are also offset dowel pins sold to align engines to transmissions when it can be determined how far off they are from each other. But that's for a slightly different purpose.

The 2.4 I just swapped in my '95 NYG winter car came to me as having a "broken timing belt". I quickly found the problem, it looked exactly like that except that the broken center section would no longer turn the rest of it.

There are two different versions of the flexplate. The one you have with a welded on ring gear and a different one that is one single piece of stamped sheet metal that includes the teeth for the starter drive. Either one works as well as the other. The stamped on is slightly lighter but nothing significant.

Post by **occasional demons** » Thu Nov 25, 2010 10:13 pm

There is also supposed to be a metal ring that acts like a common washer for the bolts to seat against. The bolt heads might have caused stress risers in the metal.

4471933 PLATE, Drive Plate Backing $3.70

Edit: Borrowed from dbesade

gtxtreme19 · Post by **gtxtreme19** » Thu Nov 25, 2010 10:30 pm

I have 3 of those little plates sitting in my garage... cool flexplate.

JeffB#2 · Post by **JeffB#2** » Thu Nov 25, 2010 10:34 pm

No idea why I didn't note the missing plate in the pictures. Too much food maybe..... that plate is critical to have in place between the bolts and the flexplate.

Post by **occasional demons** » Thu Nov 25, 2010 10:37 pm

I just recently did an engine replacement in the GF's Sundance, so it was still fresh in my mind.

JeffB#2 · Post by **JeffB#2** » Thu Nov 25, 2010 10:44 pm

And I know I put one on when I put the flexplate on the rebuilt 2.4 last month. Had to think about that for a minute, that would have been really poor on my part not to have done it. yikes.....

Jamie · Post by **Jamie** » Thu Nov 25, 2010 10:44 pm

Thats pretty good info about the stress cracks. As a matter of fact about 2 months ago I did a torque check on all the bolts around the engine bay and sure enough the bolts on the lower support bracket and the rear mid bracket were working themselves loose. It makes perfectly good sense how it all could have went down.

do you think the added stress could have caused abnormal wear on the input shaft for the auto trans? I would like to sell it but I may give it a once over just to make sure. It has good parts in it and an RMVB.

As far as that plate around the bolts for the fly wheel... I never saw it. I have had it apart about two years prior and dont remember the ring either so even that could be a contributing factor. I may have to call up a dodge dealer here in the 32765 zip and see if they have one if they are only 4 bucks.

Yet another trophy to hang on my garage wall. Thanks guys oh and by the way swapping out pedals are a royal pain in the ass for those considering it... be warned lol.
J