Hello everyone. I just replaced the fan blade on my 93 yesterday with a brand new mopar parts fan because it was making a great deal of noise which I discovered was because every blade was cracked! The new fan has about 40 miles on it and started making the same noise. Funny enough when I popped the hood I found it to have cracks in every blade that were new. Fan is mounted to original fan clutch and there is no damage to the blades as if they struck an object. Could this be a problem with the fan clutch?

 

Yeah, pics would help. What kind of sound is it making? Does it sound like its scraping something, or hitting something?

 

Do you have the new 9000 rpm governor spring? Sorry. I little Cummins humor. Don't have any idea what would cause a new fan to crack other than impact or really really really fast rotation!

 

sorry for the delay. have no camera but the cracks were at the point where the individual blades attacked to the fan hub. about 3 inches up fron the center. No other damage to the fan as if from impact. Also the fan I fust replaced had fractures on every blade in all the same spots. The sound is like a super loud rattle from the fan area but I think it is from the blades shaking after cracking

 

Is there any slop in the fan clutch as in can you wiggle it front to back? If so, that may be allowing some weird orbiting of the blade while it rotates.

The same goes for the actual fan/clutch mount bearings.

Further, obstructing the airflow be it from the front or the rear can cause weird flexing of the blades due to odd pressure zones both fore and aft.

 

no play or obstructions. I ordered the upgraded mopar clutch from the sticky. Also moparpartsamerica.com sent me right to my local dealer for a mopar warranty exchange on the fan which was cool, but I am worried that after the $70 fan and $130 clutch replacement it might happen again.

 

Put in another new fan today with a new clutch, both mopar, upgrades from sticky. Same noise from under hood and I saw that there is some play in the wterpump shaft that I didn't notice with the fan off. Dealer service guy said that the waterpump must be replaced. Anybody ever had this problem?

 

Whats loose? where the fan mounts or the water pump? I have replaced 2 water pumps 1 on my truck ( sold ) and one on a street sweeper powerplant ( just a b series vacuum cleaner ). My truck had 230,000 miles and the powerplant had 3 thousand hours on it.

 

the shaft coming out of the water pump. the fan has about 1/2 in wobble at the blade tips front to back and left to right.

 

The fan doesn't attach to the water pump. The fan is attached to a "jack shaft". Basically just a shaft attached to a block with a bearing in it. Somewhere on here is the part number for that bearing should be ~$70 for the bearing. Just have to press the old one out and the new one in.

If you are looking at the front of the engine the water pump is to the left and down just below the automatic belt tensioner. You can actually remove the water pump without taking the fan off.

Aaron

 

Thanks aaron. I thought that was the case but the dealer did not agree. I had the dealer look more into it and he stood corrected. Is it the bearing that mopar whants between 150-250 dollars for that has previously been talked of as a Fan support bearing?

 

Yes, that's what they call it.

 

Thanks for the help everyone. I ordered the part through "applied" from a previous post. They gave an updated part number of ntn df0766lluacs32. It was $70 plus shipping. Not bad compared to the 150 plus from cummins/dodge. Also case carries it under part number j910739 but it was still $120, but they had it in stock. Thanks again and I hope this fixes my problem.

 

Realized when changing the bearing that the fan support itself had a crack in it. Replaced it with a support I got from "redlinear" off ebay and it worked great. thanks again.