As I was about to exit the interstate, I heard what sounded like a rock hitting sheet metal. At the entrance to the ramp the "check gages" lite came on. I noticed the water temp at max. I drove the truck to a safe stopping point and shut it down. I raised the hood to find the serp belt all shredded and knotted up. At first thought I would just get the spare and go home. Not so simple. the pulley that runs the fan is not connected to the shaft. It looks like there should have been a bunch of small bolts holding it on. Does anyone know what size these are? Any help would be appreciated. 1999 3500 24v 6spm tran, 230,000 miles probably has all the options [ air ps pb etc ] Thanks

 

I looked at mine and i think there 5/16 fine thread USS unless there metric , Your best bet would be wait til tomorrow and call your dealer .I have no idea what length they are . If there sheared off i would just buy a new pulley they are probably grade 8 or better and to hard to drill out , Sorry i cant be more help .

 

You'll have to take a look at the radiator and the water pump too. The fan may have hit the rad and there must be a reason for these bolts shearing off. (Something having seized up and making lots of heat, you don't need the fan to keep the engine at operating temps while driving more than 30-40 mph )

AlpineRAM

 

isn't that the same pulley that runs the pump?

 

My water pump is driven by the backside of the belt just after ( or before ) this fan only pulley. Now that I have cooled down and looked at it again, it appears that the bolts just fell out. With the aid of a mirror I can see the threaded part of the fanshaft thru the pulley, A 1/4 in bolt is too big to thread into the hole. I guess I will get a few metric sizes before I leave town to be on the safe side.

 

speaking of fans I never put mine back on after the overhaul...never goes over 190 evn towing hvy

 

Anybody got a size for these bolts?

 

Pretty sure they are 10mm.

 

M6X1.25x25mm will get you bolts that you can use. That length is threaded full length, so just take a hacksaw and vise-grips if you need to cut them down to length.

I believe the stock bolts are about 12 or 15mm long, but those can be tough to get.

 

Thanks that what I was looking for. I ended up ordering from the dealer, they should be here this morning.

 

For anybody looking the oem part # is 1-04429668