new to explorer,broken crank already!

[dbake]

Soooo I take 3 months choosing what to buy,decide on 97 or newer,sohc 4.0, find one with perfect interior, 100000 miles, engine uses no oil, runs strong. First vacation 4 wks after purchase, I'm pulling a light trailer at about 30 mph and the front 3 inches of the crankshaft break off. I have since removed engine replacing with ford rebuild warranted for 3 years.
In my 40 years of driving I have never had this happen.
Has this happened to any of you?? What can I expect from this engine????

 

[Howard]

Firstly welcome.

It is very unusual to break the crankshaft. It sounds like you were just very unlucky and got one with a manufacturing defect. There are people here with way over 200,000 on an sohc with no problems. I hope this doesn't put you off. The rest of us love our x's. Now that you have got that sorted let the modding begin!!!

 

[section525]

Breaking a crank is very uncommon. Especially in a stock motor. But I once broke the output shaft in my tranny. ooops. Lack of oiling problem. Maybe something similar happened in your case. The good news is the odds aren't in favor of you doing it again.

 

[Mbrooks420]

The damper on the front of the motor may not have been working. Was there any vibration before it happened? This would twist a crank in short orfer.

 

[Magicfan25]

that is pretty odd, and the only explorer ive heard of. My friends bone stock 00GT snapped the crank in half though.

 

[Runnin'OnEmpty]

Actually this is a more common problem than it should be! Do a search for "broken crank"; there are many threads concerning it. They all break directly forward of the front main journal, and at about 80-100K miles.

It seems to be caused by a tolerance "stack-up" in manufacturing. This apparently causes an oil starvation problem, causing the crank to score and eventually break (similiar to cutting a piece of glass with a glass cutter).