I have a '98 4Runner Ltd. with 72k miles and the flywheel crackked. I caught it before it broke down. What would case this to happen? Has it happened to anyone else? Thanks.

 

Can you take some pictures and post them?

Cracking is usually caused by the rapid cooling of a very hot part.

 

Haven't seen that many come through the shop but I can get one to your front door for 282.35 including shipping. If you're interested send me an email.

Todd

 

Is this on an auto tranny vehicle? Seen plenty of flex plates crack on a variety of brands, have not seen a flywheel for a manual tranny crack to best of my memory.

 

LTD's only came in AUTO form.

 

Then its a flexplate, not flywheel (unless they came with Allison ATs )
Flexplates tend to crack at crank mounting holes, generally because bolts were not tight and its the weakest point on the flexplate due to a bunch of holes in a small space (swiss cheese effect). But sometimes they crack for no obvious reason at all, bolts were tight and everything fine.

Edited to add- Flexplates are stamped steel whereas flywheels are generally of cast iron except in high performance apps. Stamped steel can crack at flaws and other stress points.

 

thanks, but anything I may have done to cause this - like start the engine when it was already running, shift from drive to 2 abrubtly (engine braking), spin the tire aggressively in snow or sand, etc? These were some of the reason I came up with.

 

This is really odd. Do you know the history of the vehicle? Are you the original owner?

I garantee that I put my old 98 Limited Tacoma through as much, if not more than anything you could have thrown at your vehicle. I floored it constantly, burned out in snow, sand, dirt and on pavement. I held gears and bounced off the rev-limiter. You name it, I probably did it. That tranny held up to it all. No problems. This is freaky. A first for me.