My 03 DII has had a tick for ever it seems. My wife finally got sick of it and agreed that we need to replace the motor. Due to financial restraints we could not afford a used 4.6 let alone a new one. So i found a 4.0 motor that was stated to be in good shape. As I started slowly taking the motor apart to replace gaskets and the such i noticed that rod bearings 8,7, and 4 are very bad. There is about 1/2 inch play left to right on just these rods. The others are tight with no play. I need to decide what to do. I dont have a way to measure the crank journals so i am considering taking it to a machine shop to have them measure it. I wanted to get some advice from you guys first. With the bearings being this worn do you think there would be other issues? If i get it measured and the propper bearings installed should it be good to go? Not to sure where to go with this one. I am pretty good with a wrench but never got into the tolerances and minute measurements. If i do go ahead and replace them where would be the cheapest place to get the bearings and bolts? Thanks for any help
John

 

If there is 1/2" play in rod bearings then something is seriously ****ed.
Have someone take a look at it before you throw money away.

 

Maybe im exagerating 1/2 inch (im pretty upset right now) but definately enough to make loud clicking noise

 

when you say left to right, are you talking clearance between the rods, or bearing clearance?

 

not between the rods. From side to side. I pulled the bearing cap off of the one closest to the rear of motor and there was NO bearing in it. WOW. The next one was completely spun

 

that sucks. sounds like you'll probably have to grind the crankshaft and get the next size bigger bearings. But if you are going to all of that work, you could probably just repair whatever is wrong with the 4.6L

 

from what i have read and heard there is no repair. Mis-aligned dowel pins in front cover.

 

not if you've got 130k miles. That would trash the oil pump way sooner than that. Anyway, you have a nice new block that's the same. The 4.0 and the 4.6 have the same bore, same block. It's just the crank, pistons, cam and maybe rods that are different.

 

But wouldnt one or all of hose things be bad if the truck is knocking? ive read where people have thrown all kinds of parts at it and still never fixed the knock. Besides i believe the person that i got the block from is sending me another crank and some rod bearings

 

Well it's good that they are sending parts to fix it. I was just thinking that if you are going down the road of actually having to pay money to rebuild the bottom end, you might as well rebuild the 4.6