I guess U can't find out what internal repairs have been done to the motor. So going with the HB is logical even if it seems not so bad. It is crazy to think someone would un-time the balance shaft or put in unbalanced pistons/rods but maybe the wrong HB, but that seems really dumb. I'm not sure what HB would fit. Never heard of it, though I'm thinking it possible. Maybe match up the new one to check it out. If it does have the wrong HB than the diameter may be different with different belt on it too. That would make some sense in all this I suppose. UR parts dealer may be able to tell U if another HB, wrong for the engine could fit into it. I'm not sure of a production line change to an updated HB was made. Possibly out of a junk yard with the original broken with the removal of the timing cover. Really grasping huh ?

 

You never know! LOL It looks like the correct balancer to me. Has the Ford OEM sign on it. Somewhere around 2000 the 4.2 was externally balanced and the HB on the engine is for internally balanced engines so I would assume it's a match. I will post an update when I find anything out. I am not real sure how to check the casting numbers to see what the year model is on the block. Does anyone know where the numbers you decode are found and how to read them?

 

I don't know about the casting numbers, but if there is still a barcode sticker on the driver's side valve cover it has the engine build date on it. This assumes the valve cover is what came with the engine!

Now, if you don't know the history of the truck, it is VERY possible the engine has been replaced. The 97 and early 98 4.2's had defective lower intake and front cover gaskets, leading to coolant leaks and hydrolock.

 

I would follow thru with the notion of an engine swap and investigate.

 

The sticker on the VC is gone so I will do some research on the casting #'s. The local parts store wanted $160 for a Dorman HB and I purchased one for 1/2 the price on RockAuto. Thanks for that reference, glc!

 

Ur block number is by starter. Most important now.

 

Some of the mimbers should be the same as the vin but that tag is gone.

 

Ran the number on the HB and on the block today. Block came back as a 99 4.2 and the HB came back as a 3.8 balancer off of a 2002-2004 mustang. Hopefully this is the cause of my vibration mystery!!

 

A 99 block? Looks like it WAS replaced, probably due to hydrolock.

If it's a 99, you need to send the HB you bought back and get a Dorman 594081.

 

The 99 has the pulley actually on the balancer, right? All of the numbers on the accesories and brackets are for a 97...so, by the looks of the 99 balancer the crank pulley won't line up with the others. By the looks of the 99 balancer they do not have the same crank position sensor as the 97-98 but that is a RockAuto picture, too..

 

Hmm - I'm just going by the Rock Auto catalog, the part numbers between the 97 and 99 are definitely different.

 

This is turning into a circle jerk!! Ordered another HB and they sent one that is for a 2002 3.8. I can't find a crank pulley for the 4.2 HB I ordered from Rockauto...What gives? The Ford dealership don't even show it as a separate option. Are the factory 4.2 HBs a one piece design and will interchange with a 3.8 or what? Never had so much trouble with a part before.

 

Possibly this can help if wrong parts are inside motor.

http://www.enginebuildermag.com/Cont...0000003366.gif

http://www.enginebuildermag.com/Item...8l_engine.aspx