Broken Flexplate

[jimf-68sporty]

I have a 1998 Jeep Cherokee sport. I am going on my 3rd flexplate replacement in as many years. I was just wondering if there is a known problem or if this is specific to my vehicle. Please HELP!!!

[fredjacksonsan]

What happened to the first two flexplates?

(and I saw your original post about the deer accident. I take it that prior to the deer, there wasn't a problem? If the deer 'tweaked' the front end just a little, that would throw off the alignment of everything and the weakest point would break down due to an angle in the driveline.)

[jimf-68sporty]

actually, the owner previous to me also replaced flexplate, so deer accident had nothing to do with break. the plates are cracking right around bolt holes in center. no marks on teeth so that rules out starter breaking it. Harmonic balancer maybe? something amiss with torque converter? HELP!!!

[fredjacksonsan]

It sounds like something is just a little off in the alignment of the drivetrain. My brother had a similar issue on his Dodge truck - everything was fine for about 30000 miles, then the transmission case cracked. He replaced it, had everything realigned, and 30k later, cracked again. When it cracked a third time 30k later, he gave up and traded it.

So...I wish I had a solution for you. It sounds like either you're going to get really good at replacing your flex plate over time, or that next time you replace it, it'll be time to trade it in before it goes bad again.

Someone else might be along with better info, but that's what I've got to contribute. Good luck with it, post back if you find a better solution.

[hundahunta]

has the trans or converter been replaced??. if you look at the center of the converter there is a snout, which centers in the middle of the crank, the center snout of the converter helps to offset some of the weight and load of the converter. sort of like a pilot bearing or bushing on a manually trans.

[MagicRat]

This failure does pop up occasionally with these vehicles. The crack can be caused by torque converter bolts that loosen up slightly. This allows the converter to vibrate a bit, and causes a scraping/clunking sound. eventually, the vibration will fatigue the plate and crack it.

I suggest use brand new converter bolts, installed with some blue Loctite. Torque them to specs.
Then, after a couple of weeks driving, retorque them and just make sure none have loosened up.
Also, listen for the characteristic scrape/clunk noise, and tighten the bolts, if you hear it.