Here's the scoop.
My stock 89 XJ is on it's third flexplate. This will be the 3rd time in a year I will be pulling the tranny again.
I can only get a after market (Dorman). The dealer discontinued selling them otherwise I would get it from them.
I do not drive it my O'lady drives it so it's not getting beat on from hard acceleration.
I already swapped the tranny 3 months ago with a new flexplate. So we can rule out the tranny.
I checked the end play of the crank shaft and it's got quite a bit of play. So much I think the thrust bearings are worn badly. It aways cracks around the crank shaft.
Just want advise from you guys see if anyone else had this issue and if replacing the crank bearings should fix the problem for a few years

 

how much is quite a bit of play? can you get a dial indicator in there?

 

simple rule of thumb.. if you can grab the crank and move it back and forth and hear it go clunk clunk... its bad lol....

 

yeah, but .005-.010 play won't break a flexplate. so if you're trying to fix one problem at a time, it's good to know if that's what is causing the flexplate to break.

 

Sounds like the torque converter is not square to the crank. That would put the plate in a bind and cause a serious fatigue issue as it was running. Basically imaging pulling on the top of the plate and pushing on the bottom, then running it while the top and bottom points stay in those positions. That would crack the plate right around the crank very quickly.

 

I think it's alot more than that. And I know the bell housing is properly bolted to the motor.
I'm leaning toward crank endplay. Just wanna make sure. I'll try to get a dial in there and measure so I know for sure.

 

What about the torque converter?

 

You didn't say how many miles but I'm thinking crank end play.

short term...I'd get a OEM flexplate from the JY.

 

X2. very good point. the torque converter can very well cause the flexplate to break. the reason that i want u to use an indicator is that, you need to isolate the problem. sure you know that your crank has an endplay, but you might possibly have more than one problem. you know what i mean?

 

im having the same problem this time i got stuck in ca befor chrismas i live in or